Among different types of polymorphism, disappearing polymorphism deals with the metastable kinetic form which can not be reproduced after its first isolation. In the world of coordination polymers (CPs) and metal–organic frameworks (MOFs), despite the fact that many types of supramolecular isomerism exist, we are unaware of disappearing supramolecular isomerism akin to disappearing polymorphism. This work reports a MOF with dia topology that could not be reproduced, but subsequent synthesis yielded another supramolecular isomer, a double-pillared-layer MOF. When perylene was added in the same reaction, the disappeared dia MOF reappeared with perylene as a guest in the channels. Interestingly, the photoluminescence of the dia MOF with a perylene guest is dominated by the emission of the guest molecule. The influence of guest molecules on the stabilization of the supramolecular isomers of a MOF opens up a strategy to access MOFs with different structures.

While studying bats recently at the Academy of Natural Sciences in Philadelphia, Smithsonian mammalogist Kristofer Helgen discovered a new species of flying fox bat from […]

The post Smithsonian Scientist Discovers Two New Bat Species Hiding in Museum Collections for More Than 150 Years appeared first on Smithsonian Insider.

A new Smithsonian study that examines 10 million years of the evolution of tiny coral-like organisms called cupuladriid bryzoans has revealed that some species of this organism lingered on earth for more than one million years after the event that ultimately caused their extinction: the rising of the Isthmus of Panama.

The post Fossils of tiny cupuladriid colonies reveal extinction can lag more than one million years after its cause appeared first on Smithsonian Insider.

Successes in animal health care presents many new challenges for veterinarians. Longer life spans in captivity mean zoo animals are now experiencing age-related health problems that their zoo predecessors never lived long enough to develop—like diabetes in cheetahs, arthritis in big cats and dental issues for coatis.

The post Golden years at the Zoo: Veterinarians work to help animals live longer, stay healthy appeared first on Smithsonian Insider.

Invasive species, contaminants, excessive nutrient's and sediment are just some of the many factors threatening sensitive wetlands and seagrass beds.

The post Smithsonian to lead study on degradation of nearshore coastal habitats of the Chesapeake appeared first on Smithsonian Insider.

New world megafauna such as mammoths, bison and camelids that were alive at the end of the Pleistocene epoch (some 13,000 years ago) would have produced massive amounts of methane-rich flatulence and belching, thanks to the cellulose-digesting microbes in their guts.

The post Killing of methane-producing megafauna may have caused cooling 13,000 years ago appeared first on Smithsonian Insider.

Using the ancient magnetic field recorded in these rocks, a Smithsonian research group revealed Santa Marta’s 2,200-kilometer journey from northern Peru to its modern position on the Caribbean coast of Colombia during the past 170 million years.

The post Earth’s highest coastal mountain range moved 1,367 miles in 170 million years appeared first on Smithsonian Insider.

Known as one of the greatest racehorses of his day and sire to more winning horses than any other American thoroughbred before or since, this Smithsonian loan returned the legendary Lexington's remains to the town of his birthplace some 160 years after he was born.

The post One hundred sixty years after his birth a racehorse’s bones return to Lexington appeared first on Smithsonian Insider.

Tiny Antarctic marine creatures collected 100 years ago by British Royal Navy explorer Robert Falcon Scott are giving scientists new clues about polar environmental change.

The post Tiny creatures collected 100 years ago confirm accelerating carbon uptake in Antarctic Ocean appeared first on Smithsonian Insider.

Astronomers have just discovered an amazing pair of white dwarfs whirling around each other once every 39 minutes. This is the shortest-period pair of white dwarfs now known. Moreover, in a few million years they will collide and merge to create a single star.

The post Two dying stars to be reborn as one…in a few million years appeared first on Smithsonian Insider.

A remarkable 5,000-year-old deposit of bones representing an entire herd of Persian gazelles recently discovered in northeastern Syria is firm evidence, scientists say, of an ancient hunting practice largely responsible for the near extinction of gazelles in this region today.

The post Archaeological evidence confirms mass hunting of gazelles 5,000 years ago appeared first on Smithsonian Insider.

Gray whales survived many cycles of global cooling and warming over the past few million years, likely by exploiting a more varied diet than they do today, according to a new study by University of California, Berkeley, and Smithsonian Institution paleontologists.

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On Aug. 10, 1846, U.S. President James K. Polk signed the legislation that established the Smithsonian Institution as a trust administered by a Board of […]

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Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way. Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.

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An international team of scientists has discovered an ‘ordinary’ black hole in the galaxy Centaurus A. This is the first time that a normal-size black hole has been detected away from the immediate vicinity of our own Galaxy.

The post “Ordinary” black hole discovered in a galaxy 12-million-light-years away appeared first on Smithsonian Insider.

Scientists have discovered an incredible story of fungal fidelity among certain species of ants.

The post Fungal fidelity: some ants have been eating the same meal for 5 million years! appeared first on Smithsonian Insider.

Found in well preserved shale deposits the fossils are so detailed that scientists were able to determine they represent two previously unknown species.

The post Discovery of new prehistoric mosquitoes reveal these blood-suckers have changed little in 46 million years appeared first on Smithsonian Insider.

All bear species except for one live in either temperate or tropical woodlands. Only the polar bear is a stranger to the forest, living and […]

The post Polar bears in a warming world: Q&A with Don Moore of the National Zoo appeared first on Smithsonian Insider.

Unique among Earth’s creatures, turtles are the only animals to form a shell on the outside of their bodies through a fusion of modified ribs, […]

The post Discovery: Turtle shells appeared 40 million years earlier than previously believed appeared first on Smithsonian Insider.

Did you know the Smithsonian created the world’s first full cast of a whale? It was a blue whale exhibited in 1904 at the St. […]

The post 100 Years of Whales @ Smithsonian! appeared first on Smithsonian Insider.

In 2009, during an expedition by a Russian research ship, a small length of yellow flesh about 5 centimeters long was dredged up from the […]

The post Last seen 140 years ago, deep sea worm resurfaces, delighting scientists appeared first on Smithsonian Insider.

Sometime during the Middle Eocene a prehistoric mosquito slurped down a final blood meal then died and sank to the bottom of a pond in […]

The post Blood molecules preserved for millions of years in abdomen of fossil mosquito appeared first on Smithsonian Insider.

  Tiny spherules pepper a sandy surface in this 3-centimeter (1.2-inch) square view of the Martian surface. The largest one is broken in half and […]

The post 10 years roving across Mars appeared first on Smithsonian Insider.

Giant pandas. Grizzlies. Polar bears. You’ve probably heard a lot about these bear species, but what about Andean bears? To the Quechua and Aymara, the […]

The post 6 Things You Probably Didn’t Know About Andean Bears appeared first on Smithsonian Insider.

How soon after the Big Bang could water have existed? Not right away, because water molecules contain oxygen and oxygen had to be formed in […]

The post Water may Have Been Abundant in First Billion Years after big bang appeared first on Smithsonian Insider.

For the first time, a team from the Smithsonian Conservation Biology Institute’s (SCBI) Center for Conservation Education and Sustainability collected photo evidence of an Andean […]

The post Scientists Find Andean Bears with Camera Traps In Peru appeared first on Smithsonian Insider.

The world’s coasts are home to more than 70 percent of the human population and experience intense development as a result. The rate of environmental […]

The post Smithsonian Environmental Research Center Marks 50 Years of Making a Difference appeared first on Smithsonian Insider.

New fossils found in Northeastern China have revealed a remarkable evolutionary coincidence: an extinct group of insects known as Kalligrammatid lacewings (Order Neuroptera) share an […]

The post Remarkable butterfly look-alike lived 50 million years before butterflies appeared appeared first on Smithsonian Insider.

With over 138 million collection objects, 2.1 million library volumes, and 137,000 cubic feet of archives, the stories of how our collections have made their […]

The post Seventeen Objects for 170 Years (Happy Birthday to us!) appeared first on Smithsonian Insider.

The center of the Milky Way galaxy is currently a quiet place where a supermassive black hole slumbers, only occasionally slurping small sips of hydrogen […]

The post The Milky Way’s blowout bash 6 million years ago! appeared first on Smithsonian Insider.

“Think of a lion shrunk to the size of a mouse that needs to eat every 20 minutes or so.” That is a shrew, says […]

The post New Costa Rican shrew species named from a single specimen found 44 years ago appeared first on Smithsonian Insider.

The world’s most indestructible species, the tardigrade, an eight-legged micro-animal, also known as the water bear, will survive until the Sun dies, according to a […]

The post Study determines microscopic water bears will be Earth’s last survivors appeared first on Smithsonian Insider.

Using new numerical simulations and observations, scientists may now be able to explain why the Sun’s magnetic field reverses every eleven years. This significant discovery […]

The post 3D simulations reveals why the Sun flips its magnetic field every 11 years appeared first on Smithsonian Insider.

Very early on, cockroach moms found out maternal care gave their offspring a better chance at survival. The cockroach parenting method—which includes feeding, guarding and […]

The post Helicopter cockroach moms have protected their young for millions of years appeared first on Smithsonian Insider.

A mysterious cycle of booms and busts in marine biodiversity over the past 500 million years could be tied to a periodic uplifting of the world's continents, scientists report

The post Boom and bust cycle of marine biodiversity every 60 million years linked to uplifting of continents appeared first on Smithsonian Insider.

Miniature camels and horses, a rhinoceros and a giant bear-dog are among fossils unearthed in the recent excavations of the Panama Canal expansion project. These […]

The post First five years of Panama Canal excavations reveal fossil finds appeared first on Smithsonian Insider.

The post Many years of research are celebrated in the December 2010 birth of two cheetah cubs at the Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

This new PBS Newshour video takes a look at a new exhibit at the Air and Space Museum celebrating NASA's space art program.

The post PBS Newshour takes a look at the new National Air and Space Museum exhibition “NASA | ART: 50 Years of Exploration” appeared first on Smithsonian Insider.

For the first time in nearly 22 years, the Spirit of St. Louis is lowered onto the floor of the Boeing Milestones of Flight Hall. […]

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On World Elephant Day–Saturday, Aug. 12, 2017–the Smithsonian’s National Zoo celebrated Ambika the elephant’s 70th birthday. Hear her keepers of more than 30 years talk […]

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Exquisitely preserved in fossil sediments dating from the Middle Jurassic, the insect, newly named Juracimbrophlebia ginkgofolia, was discovered in 165 million-year-old deposits, as was the ginko-like tree, Yimaia capituliformis, the mimicked plant.

The post Insect mimic of ginko-like leaf discovered 165 million years after its extinction appeared first on Smithsonian Insider.

Corn, known also as maize, is a vital crop in the U.S. and throughout the Americas. First domesticated in Mexico some 9,000 years ago, scientists […]

The post Study dates corn as staple crop in Central America beginning 4,300 years ago appeared first on Smithsonian Insider.

Camouflage is a valuable survival strategy—just ask a chameleon. Scientists have just discovered a new form of mimicry camouflage: beetles that hide by chewing beetle-shaped […]

The post For millions of years these tiny beetles have chewed their way out of sight appeared first on Smithsonian Insider.

There is sufficient evidence from tree rings, boreholes, retreating glaciers, and other proxies of past surface temperatures to say with a high level of confidence that the last few decades of the 20th century were warmer than any comparable period in the last 400 years, according to a new report from the National Research Council.

Rates of physical and sexual abuse of children have declined over the last 20 years, but for reasons not fully understood, says a new report from the Institute of Medicine. Yet, reports of psychological and emotional child abuse have risen in the same period, and data vary significantly as to whether child neglect is increasing, decreasing, or remaining constant.

The National Academies Keck Futures Initiative (NAKFI) is pleased to announce the publication of Collaborations of Consequence - NAKFI’s 15 Years of Igniting Innovation at the Intersections of Disciplines.

On Feb. 26 the National Academies convened leaders from Congress, federal agencies, universities, and industry to explore how to structure science for the next 75 years to respond to the nation’s emerging needs and future challenges.