complex Workers and wearables: NIOSH webinar explores ‘opportunities and complexities’ of sensor technology By www.safetyandhealthmagazine.com Published On :: Sun, 29 Mar 2020 00:04:00 -0400 Experts on NIOSH’s Total Worker Health approach hosted a webinar exploring the “opportunities and complexities” of sensor technology. Full Article
complex Fresh Inset Brings Vidre+ Complex to U.S. By www.foodengineeringmag.com Published On :: Wed, 28 Aug 2024 10:50:00 -0400 Vidre+ makes fresh produce packaging and label functional and adaptable into a smart version with adjustable protection against the negative effects of ethylene. Full Article
complex Designing inclusive playgrounds in Switzerland: why is it so complex? By ezproxy.scu.edu.au Published On :: Thu, 01 Jun 2023 00:00:00 -0400 Children's Geographies; 06/01/2023(AN 164286256); ISSN: 14733285Academic Search Premier Full Article SWITZERLAND PLAYGROUND design & construction UNIVERSAL design SOCIAL integration CHILDREN with disabilities INTERPERSONAL relations FOCUS groups
complex Grand Peaks buys rental complex near Boca Raton for $91M –– a slight discount from its last sale price By therealdeal.com Published On :: Mon, 11 Nov 2024 20:30:00 +0000 Grand Peaks bought a 448-unit apartment complex near Boca Raton for $90.9 million, marking a slight discount from its last sale price five years ago. Denver-based Grand Peaks scooped up The Seven at West Boca at 10235 Boca Entrada Boulevard in unincorporated Palm Beach County from Tampa-based American Landmark Apartments, according to records and real […] The post Grand Peaks buys rental complex near Boca Raton for $91M –– a slight discount from its last sale price appeared first on The Real Deal. Full Article Uncategorized Boca Raton Multifamily Multifamily Market Palm Beach County
complex Morrison family’s firm pays $17M for apartment complex with workforce units near West Palm Beach By therealdeal.com Published On :: Tue, 12 Nov 2024 19:35:00 +0000 The Morrison family’s Sympatico Real Estate scooped up an apartment complex with some workforce units near West Palm Beach for $17 million. Sympatico bought the 56-unit Aviara Green at 2157 South Haverhill Road in unincorporated Palm Beach County from Delray Beach-based MAG Real Estate & Development, according to records and a news release from the […] The post Morrison family’s firm pays $17M for apartment complex with workforce units near West Palm Beach appeared first on The Real Deal. Full Article Multifamily Multifamily Market Palm Beach County Sympatico Real Estate West Palm Beach Workforce Housing
complex Participatory topological mapping: A novel approach for exploring and communicating situated knowledge of complex socio-ecological systems By ifp.nyu.edu Published On :: Sun, 03 Nov 2024 23:59:11 +0000 Methodological Innovations, Ahead of Print. Land use change impacts on Sámi reindeer husbandry are well-documented, but existing maps often fail to capture socio-ecological relationships between herders, reindeer and nature. Conventional Geographic Information Systems (GIS) simplify these relationships, lacking local context and excluding valuable knowledge due to their rigid structure. This paper introduces participatory topological mapping, […] The post Participatory topological mapping: A novel approach for exploring and communicating situated knowledge of complex socio-ecological systems was curated by information for practice. Full Article Open Access Journal Articles
complex Why do people use cryptocurrency despite all the fraud and complexity? By english.pravda.ru Published On :: Tue, 08 Sep 2020 11:33:00 +0300 With the continuous and rapid evolution of the technological era, digital currencies are gaining popularity daily. They have been gaining traction from the past half-decade. Despite the fluctuations in bitcoin and other cryptocurrencies' value, more and more people start seeing cryptocurrency as a profitable investment. For instance, if we talk about Bitcoin, one of the most popular types of cryptocurrency, it has taken over the digital currency market. If we further discuss its fame, you'll see that it is being used in some of the biggest business names around the globe, including Microsoft, Overstock, and AT&T, now accept it as a method of payment. Here, you might be thinking, why do people use cryptocurrency and cryptocurrency wallets? What are their pros and cons? Is it worth investing in cryptocurrency wallets in 2020? If you have such questions, get them answered here. But first, let us tell you about the MOST USEFUL cryptocurrency wallets. A lot of wallets are designed solely for the storage of cryptocurrencies. At a time when there was a peak in online currency exchanges and thefts, there was a need to create a wallet that will provide ultimate protection. OWNR Wallet is one of the safest bitcoin wallets to buy crypto in 2020. It helps people in keeping their digital money safe from external threats. Along with security, OWNR Wallet offers a variety of useful features for both holders and traders. Full Article Business
complex September 2006 Post of the Month: Irreducible Complexity as an Evolutionary Prediction By www.talkorigins.org Published On :: Added October 19, 2006: Full Article
complex Entrepreneurship and Democracy: A Complex Relationship By www.newswise.com Published On :: Tue, 05 Nov 2024 09:30:22 EST Full Article
complex New AI-Based Natural Language Feature Makes Complex Searches in Dimensions Faster and Easier By www.newswise.com Published On :: Thu, 07 Nov 2024 09:00:19 EST Digital Science's flagship product Dimensions has launched a beta of a new AI-based Natural Language to Query search technology. Full Article
complex Leo and Pisces Compatibility: Why Their Relationship Is Complex but Worth It By entertainment.howstuffworks.com Published On :: Sat, 09 Nov 2024 05:00:05 -0500 Explore Leo and Pisces compatibility, uncovering their strengths, weaknesses, and whether these zodiac signs can make their relationship work. Full Article
complex Synthesis and structural study of the partially disordered complex hexagonal phase δ1-MnZn9.7 By journals.iucr.org Published On :: A detailed structural characterization of the δ1-MnZn9.7 phase is presented. Full Article text
complex Synthesis and structural study of the partially disordered complex hexagonal phase δ1-MnZn9.7 By journals.iucr.org Published On :: 2024-10-02 A detailed structural analysis of the Zn-rich δ1-MnZn9.7 phase using single-crystal X-ray diffraction is presented. The δ1 phase has been synthesized by the high-temperature synthetic route. The structure crystallizes in space group P63/mmc (Pearson symbol hP556) with unit-cell parameters: a = b = 12.9051 (2) Å and c = 57.640 (1) Å. The 556 atoms are distributed over 52 Wyckoff positions in the hexagonal unit cell: seven ordered Mn sites, 37 ordered Zn sites and eight positionally disordered Zn sites. The structure predominantly consists of Frank–Kasper polyhedra (endohedral icosahedra Zn12 and icosioctahedron Zn16) and four distinct types of glue Zn atoms. The structure comprises a 127-atom supercluster (Mn13Zn114), a 38-atom extended Pearce cluster (Mn3Zn35), a 46-atom L-tetrahedron (Mn4Zn42), a Friauf polyhedron (Zn17), a disordered icosahedral cluster (MnZn12) and four glue Zn atoms. Positionally disordered Zn sites around an Mn site can be visualized as the superimposition of three differently oriented Zn12 icosahedra. Full Article text
complex Crystal structures of three uranyl–acetate–bipyridine complexes crystallized from hydraulic fracking fluid By journals.iucr.org Published On :: 2024-01-01 Hydraulic fracking exposes shale plays to acidic hydraulic fracking fluid (HFF), releasing toxic uranium (U) along with the desired oil and gas. With no existing methods to ensure U remains sequestered in the shale, this study sought to add organic ligands to HFF to explore potential U retention in shale plays. To test this possibility, incubations were set up in which uranyl acetate and one organic bipyridine ligand (either 2,2'-, 2,3'-, 2,4'-, or 4,4'-bipyridine) were added to pristine HFF as the crystallization medium. After several months and complete evaporation of all volatiles, bulk yellow crystalline material was obtained from the incubations, three of which yielded crystals suitable for single-crystal analysis, resulting in two novel structures and a high-quality structure of a previously described compound. The UO2VI acetate complexes bis(acetato-κ2O,O')(2,2'-bipyridine-κ2N,N')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,2'-bipyridine]UVIO2(CH3CO2)2, (I), and bis(acetato-κ2O,O')(2,4'-bipyridine-κN1')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,4'-bipyridine]2UVIO2(CH3CO2)2, (III), contain eight-coordinate UVI in a pseudo-hexagonal bipyramidal coordination geometry and are molecular, packing via weak C—H...O/N interactions, whereas catena-poly[bis(2,3'-bipyridinium) [di-μ-acetato-μ3-hydroxido-μ-hydroxido-di-μ3-oxido-hexaoxidotriuranium(VI)]–2,3'-bipyridine–water (1/1/1)], (C10H9N2)2[U3(C2H3O2)2O8(OH)2]·C10H8N2·H2O or {[2,3'-bipyridinium]2[2,3'-bipyridine][(UVIO2)3(O)2(OH)2(CH3CO2)2·H2O]}n, (II), forms an ionic one-dimensional polymer with seven-coordinate pentagonal bipyramidal UVI centers and hydrogen-bonding interactions within each chain. The formation of these crystals could indicate the potential for bipyridine to bind with U in shale during fracking, which will be explored in a future study via ICP-MS (inductively coupled plasma mass spectrometry) analyses of U concentration in HFF/bipyridine/shale incubations. The variation seen here between the molecular structures may indicate variance in the ability of bipyridine isomers to form complexes with U, which could impact their ability to retain U within shale in the context of fracking. Full Article text
complex Human transforming growth factor β type I receptor in complex with kinase inhibitor SB505124 By journals.iucr.org Published On :: 2024-10-23 The crystal structure of the intracellular domain of transforming growth factor β type I receptor (TβR1) in complex with the competitive inhibitor SB505124 is presented. The study provides insights into the structure and function of TβR1 in complex with SB505124, and as such offers molecular-level understanding of the inhibition of this critical signalling pathway. The potential of SB505124 as an avenue for therapy in cancer treatment is discussed on basis of the results. Full Article text
complex Exploiting Friedel pairs to interpret scanning 3DXRD data from complex geological materials By journals.iucr.org Published On :: A new processing technique for synchrotron scanning 3D X-ray diffraction data is introduced, utilizing symmetric Bragg reflections hkl and hkl, known as Friedel pairs. This technique is designed to tackle the difficulties associated with large, highly deformed, polyphase materials, especially geological samples. Full Article text
complex Crystal structure of a solvated dinuclear CuII complex derived from 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) By journals.iucr.org Published On :: In the title compound, [Cu2(L)2]·2CH2Cl2, the CuII ions coordinate two (S,O)-chelating aroylthiourea moieties of doubly deprotonated furan-2,5-dicarbonylbis(N,N-diethylthiourea) (H2L) ligands. The coordination geometry of the metal centers is best described as a flat isosceles trapezoid with a cis arrangement of the donor atoms. Full Article text
complex Exploiting Friedel pairs to interpret scanning 3DXRD data from complex geological materials By journals.iucr.org Published On :: 2024-11-08 The present study introduces a processing strategy for synchrotron scanning 3D X-ray diffraction (s3DXRD) data, aimed at addressing the challenges posed by large, highly deformed, polyphase materials such as crystalline rocks. Leveraging symmetric Bragg reflections known as Friedel pairs, our method enables diffraction events to be precisely located within the sample volume. This method allows for fitting the phase, crystal structure and unit-cell parameters at the intra-grain scale on a voxel grid. The processing workflow incorporates several new modules, designed to (i) efficiently match Friedel pairs in large s3DXRD datasets containing up to 108 diffraction peaks; (ii) assign phases to each pixel or voxel, resolving potential ambiguities arising from overlap in scattering angles between different crystallographic phases; and (iii) fit the crystal orientation and unit cell locally on a point-by-point basis. We demonstrate the effectiveness of our technique on fractured granite samples, highlighting the ability of the method to characterize complex geological materials and show their internal structure and mineral composition. Additionally, we include the characterization of a metal gasket made of a commercial aluminium alloy, which surrounded the granite sample during experiments. The results show the effectiveness of the technique in recovering information about the internal texture and residual strain of materials that have undergone high levels of plastic deformation. Full Article text
complex Crystal structure of a solvated dinuclear CuII complex derived from 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) By journals.iucr.org Published On :: 2024-11-08 Reaction between equimolar amounts of 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) (H2L) and CuCl2·2H2O in methanol in the presence of the supporting base Et3N gave rise to a neutral dinuclear complex bis[μ-3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thioureato)]dicopper(II) dichloromethane disolvate, [Cu2(C16H22N4O3S2)2]·2CH2Cl2 or [Cu2(L)2]·2CH2Cl2. The aroylbis(thioureas) are doubly deprotonated and the resulting anions {L2–} bond to metal ions through (S,O)-chelating moieties. The copper atoms adopt a virtually cis-square-planar environment. In the crystal, adjacent [Cu2(L)2]·2CH2Cl2 units are linked into polymeric chains along the a-axis direction by intermolecular coordinative Cu...S interactions. The co-crystallized solvent molecules play a vital role in the crystal packing. In particular, weak C—Hfuran...Cl and C—Hethyl...Cl contacts consolidate the three-dimensional supramolecular architecture. Full Article text
complex Using cryo-EM to understand the assembly pathway of respiratory complex I By journals.iucr.org Published On :: 2024-02-19 Complex I (proton-pumping NADH:ubiquinone oxidoreductase) is the first component of the mitochondrial respiratory chain. In recent years, high-resolution cryo-EM studies of complex I from various species have greatly enhanced the understanding of the structure and function of this important membrane-protein complex. Less well studied is the structural basis of complex I biogenesis. The assembly of this complex of more than 40 subunits, encoded by nuclear or mitochondrial DNA, is an intricate process that requires at least 20 different assembly factors in humans. These are proteins that are transiently associated with building blocks of the complex and are involved in the assembly process, but are not part of mature complex I. Although the assembly pathways have been studied extensively, there is limited information on the structure and molecular function of the assembly factors. Here, the insights that have been gained into the assembly process using cryo-EM are reviewed. Full Article text
complex The ABC toxin complex from Yersinia entomophaga can package three different cytotoxic components expressed from distinct genetic loci in an unfolded state: the structures of both shell and cargo By journals.iucr.org Published On :: 2024-05-01 Bacterial ABC toxin complexes (Tcs) comprise three core proteins: TcA, TcB and TcC. The TcA protein forms a pentameric assembly that attaches to the surface of target cells and penetrates the cell membrane. The TcB and TcC proteins assemble as a heterodimeric TcB–TcC subcomplex that makes a hollow shell. This TcB–TcC subcomplex self-cleaves and encapsulates within the shell a cytotoxic `cargo' encoded by the C-terminal region of the TcC protein. Here, we describe the structure of a previously uncharacterized TcC protein from Yersinia entomophaga, encoded by a gene at a distant genomic location from the genes encoding the rest of the toxin complex, in complex with the TcB protein. When encapsulated within the TcB–TcC shell, the C-terminal toxin adopts an unfolded and disordered state, with limited areas of local order stabilized by the chaperone-like inner surface of the shell. We also determined the structure of the toxin cargo alone and show that when not encapsulated within the shell, it adopts an ADP-ribosyltransferase fold most similar to the catalytic domain of the SpvB toxin from Salmonella typhimurium. Our structural analysis points to a likely mechanism whereby the toxin acts directly on actin, modifying it in a way that prevents normal polymerization. Full Article text
complex Chromic soft crystals based on luminescent platinum(II) complexes By journals.iucr.org Published On :: 2024-06-11 Platinum(II) complexes of square-planar geometry are interesting from a crystal engineering viewpoint because they exhibit strong luminescence based on the self-assembly of molecular units. The luminescence color changes in response to gentle stimuli, such as vapor exposure or weak mechanical forces. Both the molecular and the crystal designs for soft crystals are critical to effectively generate the chromic luminescence phenomenon of Pt(II) complexes. In this topical review, strategies for fabricating chromic luminescent Pt(II) complexes are described from a crystal design perspective, focusing on the structural regulation of Pt(II) complexes that exhibit assembly-induced luminescence via metal–metal interactions and structural control of anionic Pt(II) complexes using cations. The research progress on the evolution of various chromic luminescence properties of Pt(II) complexes, including the studies conducted by our group, are presented here along with the latest research outcomes, and an overview of the frontiers and future potential of this research field is provided. Full Article text
complex On the structure refinement of metal complexes against 3D electron diffraction data using multipolar scattering factors By journals.iucr.org Published On :: 2024-08-15 This study examines various methods for modelling the electron density and, thus, the electrostatic potential of an organometallic complex for use in crystal structure refinement against 3D electron diffraction (ED) data. It focuses on modelling the scattering factors of iron(III), considering the electron density distribution specific for coordination with organic linkers. We refined the structural model of the metal–organic complex, iron(III) acetylacetonate (FeAcAc), using both the independent atom model (IAM) and the transferable aspherical atom model (TAAM). TAAM refinement initially employed multipolar parameters from the MATTS databank for acetylacetonate, while iron was modelled with a spherical and neutral approach (TAAM ligand). Later, custom-made TAAM scattering factors for Fe—O coordination were derived from DFT calculations [TAAM-ligand-Fe(III)]. Our findings show that, in this compound, the TAAM scattering factor corresponding to Fe3+ has a lower scattering amplitude than the Fe3+ charged scattering factor described by IAM. When using scattering factors corresponding to the oxidation state of iron, IAM inaccurately represents electrostatic potential maps and overestimates the scattering potential of the iron. In addition, TAAM significantly improved the fitting of the model to the data, shown by improved R1 values, goodness-of-fit (GooF) and reduced noise in the Fourier difference map (based on the residual distribution analysis). For 3D ED, R1 values improved from 19.36% (IAM) to 17.44% (TAAM-ligand) and 17.49% (TAAM-ligand-Fe3+), and for single-crystal X-ray diffraction (SCXRD) from 3.82 to 2.03% and 1.98%, respectively. For 3D ED, the most significant R1 reductions occurred in the low-resolution region (8.65–2.00 Å), dropping from 20.19% (IAM) to 14.67% and 14.89% for TAAM-ligand and TAAM-ligand-Fe(III), respectively, with less improvement in high-resolution ranges (2.00–0.85 Å). This indicates that the major enhancements are due to better scattering modelling in low-resolution zones. Furthermore, when using TAAM instead of IAM, there was a noticeable improvement in the shape of the thermal ellipsoids, which more closely resembled those of an SCXRD-refined model. This study demonstrates the applicability of more sophisticated scattering factors to improve the refinement of metal–organic complexes against 3D ED data, suggesting the need for more accurate modelling methods and highlighting the potential of TAAM in examining the charge distribution of large molecular structures using 3D ED. Full Article text
complex Structure–property relationship of a complex photoluminescent arylacetylide-gold(I) compound. I: a pressure-induced phase transformation caught in the act By journals.iucr.org Published On :: 2024-08-23 A pressure-induced triclinic-to-monoclinic phase transition has been caught `in the act' over a wider series of high-pressure synchrotron diffraction experiments conducted on a large, photoluminescent organo-gold(I) compound. Here, we describe the mechanism of this single-crystal-to-single-crystal phase transition, the onset of which occurs at ∼0.6 GPa, and we report a high-quality structure of the new monoclinic phase, refined using aspherical atomic scattering factors. Our case illustrates how conducting a fast series of diffraction experiments, enabled by modern equipment at synchrotron facilities, can lead to overestimation of the actual pressure of a phase transition due to slow transformation kinetics. Full Article text
complex Unity gives strength: combining Bertaut's and Belov's concepts and the formalism of aperiodic crystals to solve magnetic structures of unprecedented complexity By journals.iucr.org Published On :: 2024-10-29 Full Article text
complex Solvatomorphism in a series of copper(II) complexes with the 5-phenylimidazole/perchlorate system as ligands By journals.iucr.org Published On :: 2024-07-30 In the course of an investigation of the supramolecular behaviour of copper(II) complexes with the 5-phenylimidazole/perchlorate ligand system (`blend') remarkable solvatomorphism has been observed. By employing a variety of crystallization solvents (polar protic, polar/non-polar aprotic), a series of 12 crystalline solvatomorphs with the general formula [Cu(ClO4)2(LH)4]·x(solvent) have been obtained [LH = 5-phenylimidazole, x(solvent) = 3.3(H2O) (1), 2(methanol) (2), 2(ethanol) (3), 2(1-propanol) (4), 2(2-propanol) (5), 2(2-butanol) (6), 2(dimethylformamide) (7), 2(acetone) (8), 2(tetrahydrofurane) (9), 2(1,4-dioxane) (10), 2(ethyl acetate) (11) and 1(diethyl ether) (12)]. The structures have been solved using single-crystal X-ray diffraction and the complexes were characterized by thermal analysis and infrared spectroscopy. The solvatomorphs are isostructural (triclinic, P1), with the exception of compound 9 (monoclinic, P21/n). The supramolecular structures and the role of the various solvents is discussed. All potential hydrogen-bond functionalities, both of the [Cu(ClO4)2(LH)4] units and of the solvents, are utilized in the course of the crystallization process. The supramolecular assembly in all structures is directed by strong recurring Nimidazole–H⋯Operchlorate motifs leading to robust scaffolds composed of the [Cu(ClO4)2(LH)4] host complexes. The solvents are located in channels and, with the exception of the disordered waters in 1 and the diethyl ether in 12, participate in hydrogen-bonding formation with the [Cu(ClO4)2(LH)4] complexes, serving as both hydrogen-bond acceptors and donors (for the polar protic solvents in 2–6), or solely as hydrogen-bond acceptors (for the polar/non-polar aprotic solvents in 7–11), linking the complexes and contributing to the stability of the crystalline compounds. Full Article text
complex Crystal structure of S-n-octyl 3-(1-phenylethylidene)dithiocarbazate and of its bis-chelated nickel(II) complex By journals.iucr.org Published On :: 2023-11-14 The nitrogen–sulfur Schiff base proligand S-n-octyl 3-(1-phenylethylidene)dithiocarbazate, C17H26N2S2 (HL), was prepared by reaction of S-octyl dithiocarbamate with acetophenone. Treatment of HL with nickel acetate yielded the complex bis[S-n-octyl 3-(1-phenylethylidene)dithiocarbazato]nickel(II), [Ni(C17H25N2S2)2] (NiL2), which was shown to adopt a tetrahedrally distorted cis-square-planar coordination geometry, with the NiSN planes of the two ligands forming a dihedral angle of 21.66 (6)°. Changes in the geometry of the L ligand upon chelation of Ni2+ are described, involving a ca 180° rotation around the N(azomethine)—C(thiolate) bond. Full Article text
complex Crystal structures of the isotypic complexes bis(morpholine)gold(I) chloride and bis(morpholine)gold(I) bromide By journals.iucr.org Published On :: 2023-11-16 The compounds bis(morpholine-κN)gold(I) chloride, [Au(C4H9NO)2]Cl, 1, and bis(morpholine-κN)gold(I) bromide, [Au(C4H9NO)2]Br, 2, crystallize isotypically in space group C2/c with Z = 4. The gold atoms, which are axially positioned at the morpholine rings, lie on inversion centres (so that the N—Au—N coordination is exactly linear) and the halide anions on twofold axes. The residues are connected by a classical hydrogen bond N—H⋯halide and by a short gold⋯halide contact to form a layer structure parallel to the bc plane. The morpholine oxygen atom is not involved in classical hydrogen bonding. Full Article text
complex Synthesis and crystal structures of two related Co and Mn complexes: a celebration of collaboration between the universities of Dakar and Southampton By journals.iucr.org Published On :: 2023-11-16 We report the synthesis and structures of two transition-metal complexes involving 2-(2-hydroxyphenyl)benzimidazole (2hpbi – a ligand of interest for its photoluminescent applications), with cobalt, namely, bis[μ-2-(1H-1,3-benzodiazol-2-yl)phenolato]bis[ethanol(thiocyanato)cobalt(II)], [Co2(C13H9N2O)2(NCS)2(C2H6O)2], (1), and manganese, namely, bis[μ-2-(1H-1,3-benzodiazol-2-yl)phenolato]bis{[2-(1H-1,3-benzodiazol-2-yl)phenolato](thiocyanato)manganese(III)} dihydrate, [Mn2(C13H9N2O)4(NCS)2]·2H2O, (2). These structures are two recent examples of a fruitful collaboration between researchers at the Laboratoire de Chimie de Coordination Organique/Organic Coordination Chemistry Laboratory (LCCO), University of Dakar, Senegal and the National Crystallography Service (NCS), School of Chemistry, University Southampton, UK. This productive partnership was forged through meeting at Pan-African Conferences on Crystallography and quickly grew as the plans for the AfCA (African Crystallographic Association) developed. This article therefore also showcases this productive partnership, in celebration of the IUCr's 75 year anniversary and the recent inclusion of AfCA as a Regional Associate of the IUCr. Full Article text
complex Synthesis, crystal structure and Hirshfeld surface analysis of the tetrakis complex NaNdPyr4(i-PrOH)2·i-PrOH with a carbacylamidophosphate of the amide type By journals.iucr.org Published On :: 2023-11-30 The tetrakis complex of neodymium(III), tetrakis{μ-N-[bis(pyrrolidin-1-yl)phosphoryl]acetamidato}bis(propan-2-ol)neodymiumsodium propan-2-ol monosolvate, [NaNd(C10H16Cl3N3O2)4(C3H8O)2]·C3H8O or NaNdPyr4(i-PrOH)2·i-PrOH, with the amide type CAPh ligand bis(N,N-tetramethylene)(trichloroacetyl)phosphoric acid triamide (HPyr), has been synthesized, crystallized and characterized by X-ray diffraction. The complex does not have the tetrakis(CAPh)lanthanide anion, which is typical for ester-type CAPh-based coordination compounds. Instead, the NdO8 polyhedron is formed by one oxygen atom of a 2-propanol molecule and seven oxygen atoms of CAPh ligands in the title compound. Three CAPh ligands are coordinated in a bidentate chelating manner to the NdIII ion and simultaneously binding the sodium cation by μ2-bridging PO and CO groups while the fourth CAPh ligand is coordinated to the sodium cation in a bidentate chelating manner and, due to the μ2-bridging function of the PO group, also binds the neodymium ion. Full Article text
complex Synthesis, crystal structure and Hirshfeld surface analysis of a cadmium complex of naphthalene-1,5-disulfonate and o-phenylenediamine By journals.iucr.org Published On :: 2023-11-30 A novel o-phenylenediamine (opda)-based cadmium complex, bis(benzene-1,2-diamine-κ2N,N')bis(benzene-1,2-diamine-κN)cadmium(II) naphthalene-1,5-disulfonate, [Cd(C6H8N2)4](C10H6O6S2), was synthesized. The complex salt crystallizes in the monoclinic space group C2/c. The Cd atom occupies a special position and coordinates six nitrogen atoms from four o-phenylenediamine molecules, two as chelating ligands and two as monodentate ligands. The amino H atoms of opda interact with two O atoms of the naphthalene-1,5-disulfonate anions. The anions act as bridges between [Cd(opda)4]2+ cations, forming a two-dimensional network in the [010] and [001] directions. The Hirshfeld surface analysis shows that the primary factors contributing to the supramolecular interactions are short contacts, particularly van der Waals forces of the type H⋯H, O⋯H and C⋯H. Full Article text
complex The synthesis and structural properties of a chloridobis{N-[(4-methoxyphenyl)imino]pyrrolidine-1-carboxamide}zinc(II) (acetonitrile)trichloridozincate coordination complex By journals.iucr.org Published On :: 2024-01-01 The title complex, [ZnCl(C12H15N3O2)2][ZnCl3(CH3CN)], was synthesized and its structure was fully characterized through single-crystal X-ray diffraction analysis. The complex crystallizes in the orthorhombic system, space group Pbca (61), with a central zinc atom coordinating one chlorine atom and two pyrrolidinyl-4-methoxyphenyl azoformamide ligands in a bidentate manner, utilizing both the nitrogen and oxygen atoms in a 1,3-heterodiene (N=N—C=O) motif for coordinative bonding, yielding an overall positively (+1) charged complex. The complex is accompanied by a [(CH3CN)ZnCl3]− counter-ion. The crystal data show that the harder oxygen atoms in the heterodiene zinc chelate form bonding interactions with distances of 2.002 (3) and 2.012 (3) Å, while nitrogen atoms are coordinated by the central zinc cation with bond lengths of 2.207 (3) and 2.211 (3) Å. To gain further insight into the intermolecular interactions within the crystal, Hirshfeld surface analysis was performed, along with the calculation of two-dimensional fingerprint plots. This analysis revealed that H⋯H (39.9%), Cl⋯H/H⋯Cl (28.2%) and C⋯H/H⋯C (7.2%) interactions are dominant. This unique crystal structure sheds light on arrangement and bonding interactions with azoformamide ligands, and their unique qualities over similar semicarbazone and azothioformamide structures. Full Article text
complex Crystal structures of sixteen phosphane chalcogenide complexes of gold(I) chloride, bromide and iodide By journals.iucr.org Published On :: 2024-01-01 The structures of 16 phosphane chalcogenide complexes of gold(I) halides, with the general formula R13-nR2nPEAuX (R1 = t-butyl; R2 = isopropyl; n = 0 to 3; E = S or Se; X = Cl, Br or I), are presented. The eight possible chlorido derivatives are: 1a, n = 3, E = S; 2a, n = 2, E = S; 3a, n = 1, E = S; 4a, n = 0, E = S; 5a, n = 3, E = Se; 6a, n = 2, E = Se; 7a, n = 1, E = Se; and 8a, n = 0, E = Se, and the corresponding bromido derivatives are 1b–8b in the same order. However, 2a and 2b were badly disordered and 8a was not obtained. The iodido derivatives are 2c, 6c and 7c (numbered as for the series a and b). All structures are solvent-free and all have Z' = 1 except for 6b and 6c (Z' = 2). All molecules show the expected linear geometry at gold and approximately tetrahedral angles P—E—Au. The presence of bulky ligands forces some short intramolecular contacts, in particular H⋯Au and H⋯E. The Au—E bond lengths have a slight but consistent tendency to be longer when trans to a softer X ligand, and vice versa. The five compounds 1a, 5a, 6a, 1b and 5b form an isotypic set, despite the different alkyl groups in 6a. Compounds 3a/3b, 4b/8b and 6b/6c form isotypic pairs. The crystal packing can be analysed in terms of various types of secondary interactions, of which the most frequent are `weak' hydrogen bonds from methine hydrogen atoms to the halogenido ligands. For the structure type 1a, H⋯X and H⋯E contacts combine to form a layer structure. For 3a/3b, the packing is almost featureless, but can be described in terms of a double-layer structure involving borderline H⋯Cl/Br and H⋯S contacts. In 4a and 4b/8b, which lack methine groups, Cmethyl—H⋯X contacts combine to form layer structures. In 7a/7b, short C—H⋯X interactions form chains of molecules that are further linked by association of short Au⋯Se contacts to form a layer structure. The packing of compound 6b/6c can conveniently be analysed for each independent molecule separately, because they occupy different regions of the cell. Molecule 1 forms chains in which the molecules are linked by a Cmethine⋯Au contact. The molecules 2 associate via a short Se⋯Se contact and a short H⋯X contact to form a layer structure. The packing of compound 2c can be described in terms of two short Cmethine—H⋯I contacts, which combine to form a corrugated ribbon structure. Compound 7c is the only compound in this paper to feature Au⋯Au contacts, which lead to twofold-symmetric dimers. Apart from this, the packing is almost featureless, consisting of layers with only translation symmetry except for two very borderline Au⋯H contacts. Full Article text
complex Crystal structures of ten phosphane chalcogenide complexes of gold(III) chloride and bromide By journals.iucr.org Published On :: 2024-03-12 The structures of ten phosphane chalcogenide complexes of gold(III) halides, with general formula R13–nR2nPEAuX3 (R1 = t-butyl; R2 = i-propyl; n = 0 to 3; E = S or Se; X = Cl or Br) are presented. The eight possible chlorido derivatives are: 9a, n = 3, E = S; 10a, n = 2, E = S; 11a, n = 1, E = S; 12a, n = 0, E = S; 13a, n = 3, E = Se; 14a, n = 2, E = Se; 15a, n = 1, E = Se; and 16a, n = 0, E = Se, and the corresponding bromido derivatives are 9b–16b in the same order. Structures were obtained for 9a, 10a (and a second polymorph 10aa), 11a (and its deuterochloroform monosolvate 11aa), 12a (as its dichloromethane monosolvate), 14a, 15a (as its deuterochloroform monosolvate 15aa, in which the solvent molecule is disordered over two positions), 9b, 11b, 13b and 15b. The structures of 11a, 15a, 11b and 15b form an isotypic set, and those of compounds 10aa and 14a form an isotypic pair. All structures have Z' = 1. The gold(III) centres show square-planar coordination geometry and the chalcogenide atoms show approximately tetrahedral angles (except for the very wide angle in 12a, probably associated with the bulky t-butyl groups). The bond lengths at the gold atoms are lengthened with respect to the known gold(I) derivatives, and demonstrate a considerable trans influence of S and Se donor atoms on a trans Au—Cl bond. Each compound with an isopropyl group shows a short intramolecular contact of the type C—Hmethine⋯Xcis; these may be regarded as intramolecular ‘weak’ hydrogen bonds, and they determine the orientation of the AuX3 groups. The molecular packing is analysed in terms of various short contacts such as weak hydrogen bonds C—H⋯X and contacts between the heavier atoms, such as X⋯X (9a, 10aa, 11aa, 15aa and 9b), S⋯S (10aa, 11a and 12a) and S⋯Cl (10a). The packing of the polymorphs 10a and 10aa is thus quite different. The solvent molecules take part in C—H⋯Cl hydrogen bonds; for 15aa, a disordered solvent region at z ≃ 0 is observed. Structure 13b involves unusual inversion-symmetric dimers with Se⋯Au and Se⋯Br contacts, further connected by Br⋯Br contacts. Full Article text
complex Synthesis, crystal structure and properties of the trigonal–bipyramidal complex tris(2-methylpyridine N-oxide-κO)bis(thiocyanato-κN)cobalt(II) By journals.iucr.org Published On :: 2024-04-11 Reaction of Co(NCS)2 with 2-methylpyridine N-oxide in a 1:3 ratio in n-butanol leads to the formation of crystals of tris(2-methylpyridine N-oxide-κO)bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)3]. The asymmetric unit of the title compound consists of one CoII cation two thiocyanate anions and three crystallographically independent 2-methylpyridine N-oxide coligands in general positions. The CoII cations are trigonal–bipyramidally coordinated by two terminal N-bonding thiocyanate anions in the trans-positions and three 2-methylpyridine N-oxide coligands into discrete complexes. These complexes are linked by intermolecular C–H⋯S interactions into double chains that elongate in the c-axis direction. Powder X-ray diffraction (PXRD) measurements prove that all batches are always contaminated with an additional and unknown crystalline phase. Thermogravimetry and differential analysis of crystals selected by hand reveal that the title compound decomposes at about 229°C in an exothermic reaction. At about 113°C a small endothermic signal is observed that, according to differential scanning calorimetry (DSC) measurements, is irreversible. PXRD measurements of the residue prove that a poorly crystalline and unknown phase has formed and thermomicroscopy indicates that some phase transition occurs that is accompanied with a color change of the title compound. Full Article text
complex Synthesis, crystal structure and thermal properties of the dinuclear complex bis(μ-4-methylpyridine N-oxide-κ2O:O)bis[(methanol-κO)(4-methylpyridine N-oxide-κO)bis(thiocyanato-κN)cobalt(II)] By journals.iucr.org Published On :: 2024-04-18 Reaction of Co(NCS)2 with 4-methylpyridine N-oxide in methanol leads to the formation of crystals of the title compound, [Co2(NCS)4(C6H7NO)4(CH4O)2] or Co2(NCS)4(4-methylpyridine N-oxide)4(methanol)2. The asymmetric unit consist of one CoII cation, two thiocyanate anions, two 4-methylpyridine N-oxide coligands and one methanol molecule in general positions. The H atoms of one of the methyl groups are disordered and were refined using a split model. The CoII cations octahedrally coordinate two terminal N-bonded thiocyanate anions, three 4-methylpyridine N-oxide coligands and one methanol molecule. Each two CoII cations are linked by pairs of μ-1,1(O,O)-bridging 4-methylpyridine N-oxide coligands into dinuclear units that are located on centers of inversion. Powder X-ray diffraction (PXRD) investigations prove that the title compound is contaminated with a small amount of Co(NCS)2(4-methylpyridine N-oxide)3. Thermogravimetric investigations reveal that the methanol molecules are removed in the beginning, leading to a compound with the composition Co(NCS)2(4-methylpyridine N-oxide), which has been reported in the literature and which is of poor crystallinity. Full Article text
complex Structure of the five-coordinate CoII complex (1H-imidazole){tris[(1-benzyltriazol-4-yl-κN3)methyl]amine-κN}cobalt(II) bis(tetrafluoroborate) By journals.iucr.org Published On :: 2024-04-18 The title compound, [Co(C3H4N2)(C30H30N10)](BF4)2, is a five-coordinate CoII complex based on the neutral ligands tris[(1-benzyltriazol-4-yl)methyl]amine (tbta) and imidazole. It exhibits a distorted trigonal bipyramidal geometry in which the equatorial positions are occupied by the three N-atom donors from the triazole rings of the tripodal tbta ligand. The apical amine N-atom donor of tbta and the N-atom donor of the imidazole ligand occupy the axial positions of the coordination sphere. Two tetrafluoroborate anions provide charge balance in the crystal. Full Article text
complex Synthesis, crystal structure and anticancer activity of the complex chlorido(η2-ethylene)(quinolin-8-olato-κ2N,O)platinum(II) by experimental and theoretical methods By journals.iucr.org Published On :: 2024-04-30 The complex [Pt(C9H6NO)Cl(C2H4)], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hydroxyquinoline (C9H6NO) coordinates with the PtII atom via the N and O atoms while the ethylene coordinates in the η2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C—H⋯O, C—H⋯π, Cl⋯π and Pt⋯π interactions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC50 values of 0.8 and 0.4 µM, respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethylene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethylene with H2O and the water with the guanine molecule. Full Article text
complex Crystal structure and Hirshfeld surface of a pentaaminecopper(II) complex with urea and chloride By journals.iucr.org Published On :: 2024-05-14 The reaction of copper(II) oxalate and hexamethylenetetramine in a deep eutectic solvent made of urea and choline chloride produced crystals of pentaaminecopper(II) dichloride–urea (1/1), [Cu(NH3)5]Cl2·CO(NH2)2, which was characterized by single-crystal X-ray diffraction. The complex contains discrete pentaaminecopper(II) units in a square-based pyramidal geometry. The overall structure of the multi-component crystal is dictated by hydrogen bonding between urea molecules and amine H atoms with chloride anions. Full Article text
complex Crystal structure of a three-coordinate lithium complex with monodentate phenyloxazoline and hexamethyldisilylamide ligands By journals.iucr.org Published On :: 2024-05-17 The reaction of lithium hexamethyldisilylamide, [Li{N(Si(CH3)3)2}] (LiHMDS), with 4,4-dimethyl-2-phenyl-2-oxazoline (Phox, C11H13NO) in hexane produced colourless crystals of bis(4,4-dimethyl-2-phenyl-2-oxazoline-κN)(hexamethyldisilylamido-κN)lithium, [Li(C6H18NSi2)(C11H13NO)2] or [Li{N(Si(CH3)3)2}(Phox)2] in high yield (89%). Despite the 1:1 proportion of the starting materials in the reaction mixture, the product formed with a 1:2 amide:oxazoline ratio. In the unit cell of the C2/c space group, the neutral molecules lie on twofold rotation axes coinciding with the Li—N(amide) bonds. The lithium(I) centre adopts a trigonal–planar coordination geometry with three nitrogen donor atoms, one from the HMDS anion and two from the oxazolines. All ligands are monodentate. In the phenyloxazoline units, the dihedral angle defined by the five-membered heterocyclic rings is 35.81 (5)°, while the phenyl substituents are approximately face-to-face, separated by 3.908 (5) Å. In the amide, the methyl groups assume a nearly eclipsed arrangement to minimize steric repulsion with the analogous substituents on the oxazoline rings. The non-covalent interactions in the solid-state structure of [Li{N(Si(CH3)3)2}(Phox)2] were assessed by Hirshfeld surface analysis and fingerprint plots. This new compound is attractive for catalysis due to its unique structural features. Full Article text
complex Trifluoromethanesulfonate salt of 5,10,15,20-tetrakis(1-benzylpyridin-1-ium-4-yl)-21H,23H-porphyrin and its CaII complex By journals.iucr.org Published On :: 2024-05-21 The synthesis, crystallization and characterization of a trifluoromethanesulfonate salt of 5,10,15,20-tetrakis(1-benzylpyridin-1-ium-4-yl)-21H,23H-porphyrin, C68H54N84+·4CF3SO3−·4H2O, 1·OTf, are reported in this work. The reaction between 5,10,15,20-tetrakis(pyridin-4-yl)-21H,23H-porphyrin and benzyl bromide in the presence of 0.1 equiv. of Ca(OH)2 in CH3CN under reflux with an N2 atmosphere and subsequent treatment with silver trifluoromethanesulfonate (AgOTf) salt produced a red–brown solution. This reaction mixture was filtered and the solvent was allowed to evaporate at room temperature for 3 d to give 1·OTf. Crystal structure determination by single-crystal X-ray diffraction (SCXD) revealed that 1·OTf crystallizes in the space group P21/c. The asymmetric unit contains half a porphyrin molecule, two trifluoromethanesulfonate anions and two water molecules of crystallization. The macrocycle of tetrapyrrole moieties is planar and unexpectedly it has coordinated CaII ions in occupational disorder. This CaII ion has only 10% occupancy (C72H61.80Ca0.10F12N8O16S4). The pyridinium rings bonded to methylene groups from porphyrin are located in two different arrangements in almost orthogonal positions between the plane formed by the porphyrin and the pyridinium rings. The crystal structure features cation⋯π interactions between the CaII atom and the π-system of the phenyl ring of neighboring molecules. Both trifluoromethanesulfonate anions are found at the periphery of 1, forming hydrogen bonds with water molecules. Full Article text
complex Synthesis and crystal structures of three organoplatinum(II) complexes bearing natural arylolefin and quinoline derivatives By journals.iucr.org Published On :: 2024-05-21 Three organoplatinum(II) complexes bearing natural arylolefin and quinoline derivatives, namely, [4-methoxy-5-(2-methoxy-2-oxoethoxy)-2-(prop-2-en-1-yl)phenyl](quinolin-8-olato)platinum(II), [Pt(C13H15O4)(C9H6NO)], (I), [4-methoxy-5-(2-oxo-2-propoxyethoxy)-2-(prop-2-en-1-yl)phenyl](quinoline-2-carboxylato)platinum(II), [Pt(C15H19O4)(C10H6NO2)], (II), and chlorido[4-methoxy-5-(2-oxo-2-propoxyethoxy)-2-(prop-2-en-1-yl)phenyl](quinoline)platinum(II), [Pt(C15H19O4)Cl(C9H7N)], (III), were synthesized and structurally characterized by IR and 1H NMR spectroscopy, and by single-crystal X-ray diffraction. The results showed that the cycloplatinated arylolefin coordinates with PtII via the carbon atom of the phenyl ring and the C=Colefinic group. The deprotonated 8-hydroxyquinoline (C9H6NO) and quinoline-2-carboxylic acid (C10H6NO2) coordinate with the PtII atom via the N and O atoms in complexes (I) and (II) while the quinoline (C9H7N) coordinates via the N atom in (III). Moreover, the coordinating N atom in complexes (I)–(III) is in the cis position compared to the C=Colefinic group. The crystal packing is characterized by C—H⋯π, C—H⋯O [for (II) and (III)], C—H⋯Cl [for (III) and π–π [for (I)] interactions. Full Article text
complex Structural characterization of the supramolecular complex between a tetraquinoxaline-based cavitand and benzonitrile By journals.iucr.org Published On :: 2024-05-31 The structural characterization is reported of the supramolecular complex between the tetraquinoxaline-based cavitand 2,8,14,20-tetrahexyl-6,10:12,16:18,22:24,4-O,O'-tetrakis(quinoxaline-2,3-diyl)calix[4]resorcinarene (QxCav) with benzonitrile. The complex, of general formula C84H80N8O8·2C7H5N, crystallizes in the space group Poverline{1} with two independent molecules in the asymmetric unit, displaying very similar geometrical parameters. For each complex, one of the benzonitrile molecules is engulfed inside the cavity, while the other is located among the alkyl legs at the lower rim. The host and the guests mainly interact through weak C—H⋯π, C—H⋯N and dispersion interactions. These interactions help to consolidate the formation of supramolecular chains running along the crystallographic b-axis direction. Full Article text
complex Syntheses and crystal structures of the five- and sixfold coordinated complexes diisoselenocyanatotris(2-methylpyridine N-oxide)cobalt(II) and diisoselenocyanatotetrakis(2-methylpyridine N- By journals.iucr.org Published On :: 2024-06-07 The reaction of CoBr2, KNCSe and 2-methylpyridine N-oxide (C6H7NO) in ethanol leads to the formation of crystals of [Co(NCSe)2(C6H7NO)3] (1) and [Co(NCSe)2(C6H7NO)4] (2) from the same reaction mixture. The asymmetric unit of 1 is built up of one CoII cation, two NCSe− isoselenocyanate anions and three 2-methylpyridine N-oxide coligands, with all atoms located on general positions. The asymmetric unit of 2 consists of two cobalt cations, four isoselenocanate anions and eight 2-methylpyridine N-oxide coligands in general positions, because two crystallographically independent complexes are present. In compound 1, the CoII cations are fivefold coordinated to two terminally N-bonded anionic ligands and three 2-methylpyridine N-oxide coligands within a slightly distorted trigonal–bipyramidal coordination, forming discrete complexes with the O atoms occupying the equatorial sites. In compound 2, each of the two complexes is coordinated to two terminally N-bonded isoselenocyanate anions and four 2-methylpyridine N-oxide coligands within a slightly distorted cis-CoN2O4 octahedral coordination geometry. In the crystal structures of 1 and 2, the complexes are linked by weak C—H⋯Se and C—H⋯O contacts. Powder X-ray diffraction reveals that neither of the two compounds were obtained as a pure crystalline phase. Full Article text
complex Crystal structures of four gold(I) complexes [AuL2]+[AuX2]− and a by-product (L·LH+)[AuBr2]− (L = substituted pyridine, X = Cl or Br) By journals.iucr.org Published On :: 2024-06-18 Bis(2-methylpyridine)gold(I) dibromidoaurate(I), [Au(C6H7N)2][AuBr2], (1), crystallizes in space group C2/c with Z = 4. Both gold atoms lie on twofold axes and are connected by an aurophilic contact. A second aurophilic contact leads to infinite chains of alternating cations and anions parallel to the b axis, and the residues are further connected by a short H⋯Au contact and a borderline Br⋯Br contact. Bis(3-methylpyridine)gold(I) dibromidoaurate(I), [Au(C6H7N)2][AuBr2], (2), crystallizes in space group C2/m with Z = 2. Both gold atoms lie on special positions with symmetry 2/m and are connected by an aurophilic contact; all other atoms except for one methyl hydrogen lie in mirror planes. The extended structure is closely analogous to that of 1, although the structures are formally not isotypic. Bis(3,5-dimethylpyridine)gold(I) dichloridoaurate(I), [Au(C7H9N)2][AuCl2], (3) crystallizes in space group Poverline{1} with Z = 2. The cation lies on a general position, and there are two independent anions in which the gold atoms lie on inversion centres. The cation and one anion associate via three short H⋯Cl contacts to form a ribbon structure parallel to the b axis; aurophilic contacts link adjacent ribbons. Bis(3,5-dimethylpyridine)gold(I) dibromidoaurate(I), [Au(C7H9N)2][AuBr2], (4) is isotypic to 3. Attempts to make similar compounds involving 2-bromopyridine led instead to 2-bromopyridinium dibromidoaurate(I)–2-bromopyridine (1/1), (C5H5BrN)[AuBr2]·C5H4BrN, (5), which crystallizes in space group Poverline{1} with Z = 2; all atoms lie on general positions. The 2-bromopyridinium cation is linked to the 2-bromopyridine molecule by an N—H⋯N hydrogen bond. Two formula units aggregate to form inversion-symmetric dimers involving Br⋯Br, Au⋯Br and H⋯Br contacts. Full Article text
complex Two chromium(II) acetate complexes with N-heterocyclic carbene (NHC) coligands By journals.iucr.org Published On :: 2024-06-28 Tetrakis(μ-acetato-κ2O:O')bis{[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene-κC2]chromium(II)} tetrahydrofuran disolvate, [Cr2(C2H3O2)4(C27H36N4)2]·2C4H8O or [Cr2(OAc)4(IDipp)2]·2C4H8O (1), and tetrakis(μ-acetato-κ2O:O')bis{[1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene-κC2]chromium(II)}, {Cr2(C2H3O2)4(C21H24N2)2] or [Cr2(OAc)4(IMes)2] (2), were synthesized from anhydrous chromium(II) acetate [Cr2(OAc)4] and the corresponding NHC (NHC = N-heterocyclic carbene) in toluene as solvent. Both complexes crystallize in the triclinic system, space group Poverline{1}. The molecular structures consist of Cr2(OAc)4 paddle-wheels that carry two terminal NHC ligands. This leads to a square-pyramidal coordination of the chromium atoms. Full Article text
complex The crystal structure of a mononuclear PrIII complex with cucurbit[6]uril By journals.iucr.org Published On :: 2024-06-25 A new mononuclear complex, pentaaqua(cucurbit[6]uril-κ2O,O')(nitrato-κ2O,O')praseodymium(III) dinitrate 9.56-hydrate, [Pr(NO3)(CB6)(H2O)5](NO3)2·9.56H2O (1), was obtained as outcome of the hydrothermal reaction between the macrocyclic ligand cucurbit[6]uril (CB6, C36H36N24O12) with a tenfold excess of Pr(NO3)3·6H2O. Complex 1 crystallizes in the P21/n space group with two crystallographically independent but chemically identical [Pr(CB6)(NO3)(H2O)5]2+ complex cations, four nitrate counter-anions and 19.12 interstitial water molecules per asymmetric unit. The nonacoordinated PrIII in 1 are located in the PrO9 coordination environment formed by two carbonyl O atoms from bidentate cucurbit[6]uril units, two oxygen atoms from the bidentate nitrate anion and five water molecules. Considering the differences in Pr—O bond distances and O—Pr—O angles in the coordination spheres, the coordination polyhedrons of the two PrIII atoms can be described as distorted spherical capped square antiprismatic and muffin polyhedral. Full Article text
complex Synthesis, crystal structure and photophysical properties of a dinuclear MnII complex with 6-(diethylamino)-4-phenyl-2-(pyridin-2-yl)quinoline By journals.iucr.org Published On :: 2024-06-28 A new quinoline derivative, namely, 6-(diethylamino)-4-phenyl-2-(pyridin-2-yl)quinoline, C24H23N3 (QP), and its MnII complex aqua-1κO-di-μ-chlorido-1:2κ4Cl:Cl-dichlorido-1κCl,2κCl-bis[6-(diethylamino)-4-phenyl-2-(pyridin-2-yl)quinoline]-1κ2N1,N2;2κ2N1,N2-dimanganese(II), [Mn2Cl4(C24H23N3)2(H2O)] (MnQP), were synthesized. Their compositions have been determined with ESI-MS, IR, and 1H NMR spectroscopy. The crystal-structure determination of MnQP revealed a dinuclear complex with a central four-membered Mn2Cl2 ring. Both MnII atoms bind to an additional Cl atom and to two N atoms of the QP ligand. One MnII atom expands its coordination sphere with an extra water molecule, resulting in a distorted octahedral shape. The second MnII atom shows a distorted trigonal–bipyramidal shape. The UV–vis absorption and emission spectra of the examined compounds were studied. Furthermore, when investigating the aggregation-induced emission (AIE) properties, it was found that the fluorescent color changes from blue to green and eventually becomes yellow as the fraction of water in the THF/water mixture increases from 0% to 99%. In particular, these color and intensity changes are most pronounced at a water fraction of 60%. The crystal structure contains disordered solvent molecules, which could not be modeled. The SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–18] was used to obtain information on the type and quantity of solvent molecules, which resulted in 44 electrons in a void volume of 274 Å3, corresponding to approximately 1.7 molecules of ethanol in the unit cell. These ethanol molecules are not considered in the given chemical formula and other crystal data. Full Article text
complex Crystal structures of seven gold(III) complexes of the form LAuX3 (L = substituted pyridine, X = Cl or Br) By journals.iucr.org Published On :: 2024-07-31 The structures of seven gold(III) halide derivatives of general formula LAuX3 (L = methylpyridines or dimethylpyridines, X = Cl or Br) are presented: trichlorido(2-methylpyridine)gold(III), [AuCl3(C6H7N)], 1 (as two polymorphs 1a and 1b); tribromido(2-methylpyridine)gold(III), [AuBr3(C6H7N)], 2; tribromido(3-methylpyridine)gold(III), [AuBr3(C6H7N)], 3; tribromido(2,4-dimethylpyridine)gold(III), [AuBr3(C7H9N)], 4; trichlorido(3,5-dimethylpyridine)gold(III), [AuCl3(C7H9N)], 5; tribromido(3,5-dimethylpyridine)gold(III), [AuBr3(C7H9N)], 6, and trichlorido(2,6-dimethylpyridine)gold(III), [AuCl3(C7H9N)], 7. Additionally, the structure of 8, the 1:1 adduct of 2 and 6, [AuBr3(C6H7N)]·[AuBr3(C7H9N)], is included. All the structures crystallize solvent-free, and all have Z' = 1 except for 5 and 7, which display crystallographic twofold rotation symmetry, and 4, which has Z' = 2. 1a and 2 are isotypic. The coordination geometry at the gold(III) atoms is, as expected, square-planar. Four of the crystals (1a, 1b, 2 and 8) were non-merohedral twins, and these structures were refined using the ‘HKLF 5’ method. The largest interplanar angles between the pyridine ring and the coordination plane are observed for those structures with a 2-methyl substituent of the pyridine ring. The Au—N bonds are consistently longer trans to Br (average 2.059 Å) than trans to Cl (average 2.036 Å). In the crystal packing, a frequent feature is the offset-stacked and approximately rectangular dimeric moiety (Au—X)2, with antiparallel Au—X bonds linked by Au⋯X contacts at the vacant positions axial to the coordination plane. The dimers are connected by further secondary interactions (Au⋯X or X⋯X contacts, `weak' C—H⋯X hydrogen bonds) to form chain, double chain (`ladder') or layer structures, and in several cases linked again in the third dimension. Only 1b and 7 contain no offset dimers; these structures instead involve C—H⋯Cl hydrogen bonds combined with Cl⋯Cl contacts (1b) or Cl⋯π contacts (7). The packing patterns of seven further complexes LAuX3 involving simple pyridines (taken from the Cambridge Structural Database) are compared with those of 1–8. Full Article text
complex Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2'-(4H-1,2,4-triazole-3,5-diyl)diacetate By journals.iucr.org Published On :: 2024-08-30 The title compound, bis[μ-2,2'-(4H-1,2,4-triazole-3,5-diyl)diacetato]bis[diaquacopper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octahedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitrogen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxylate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water molecules. Two additional solvent water molecules are linked to the title molecule by O—H⋯N and O⋯H—O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supramolecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) interactions. The crystal studied was twinned by a twofold rotation around [100]. Full Article text