In honour of scientist and astronomer Nicolaus Copernicus (1473-1543), the discovering team around Professor Sigurd Hofmann suggested the name copernicium with the element symbol Cp for the new element 112, discovered at the GSI Helmholtzzentrum für Schwerionenforschung (Center for Heavy Ion Research) in Darmstadt. It was Copernicus who discovered that the Earth orbits the Sun, thus paving the way for our modern view of the world. Thirteen years ago, element 112 was discovered by an international team of scientists at the GSI accelerator facility. A few weeks ago, the International Union of Pure and Applied Chemistry, IUPAC, officially confirmed their discovery. In around six months, IUPAC will officially endorse the new element's name. This period is set to allow the scientific community to discuss the suggested name copernicium before the IUPAC naming.

Darmstadt, June 10, 2009

The new element 112 discovered by GSI has been officially recognized and will be named by the Darmstadt group in due course. Their suggestion should be made public over this summer.

Everyone knows that elemental nitrogen exists in the atmosphere as dinitrogen, N₂. There is a triple bond between the two nitrogen atoms. This is true - but under certain conditions, a fascinating N-N single bonded phase has been characterized.

In 1985 it was predicted that at high pressure, nitrogen would transform to a solid with a single-bonded crystalline structure called polymeric nitrogen. Later, it was proposed that it whould have a cubic gauche (cg-N) structure. Experimental evidence was scant however until 2004 when a team of scientists from Germany and Russia managed to make the compound directly from molecular nitrogen at temperatures above 2000 K and pressures above 110 GPa using a laser-heated diamond cell. The material was characterized by X-ray and Raman scattering methods we have identified this as the polymeric nitrogen (cg-N).

The phase is a stiff with a bulk modulus ≥300 GPa. This is characteristic of strong covalent solids. The polymeric nitrogen is metastable. The structure of N is polymeric with each nitrogen bound to three other nitrogen atoms. At a pressure of 115 GPa, each N-N bond length is 1.346 ± 0.004 Å. The N-N-N angles are all about 108.8°, very close to the ideal tetrahedral angle of just over 109°.

It did not prove possible to recover the polymeric nitrogen by releasing the pressure - in other words the polymer reverts to normal dinitrogen. The authors speculate that this form of nitrogen is a new class of single-bonded nitrogen materials that may have unique energy capacity properties (more than five times that of the most powerful energetic materials).

References

1. "Single-Bonded Cubic Form Of Nitrogen", M.I. Eremets, A.G. Gavriliuk, I.A. Trojan, D.A. Dzivenko, and R. Boehler, Nature (Materials), 2004, 3, 558. [doi:10.1038/nmat1146]

Scientists at the Lawrence Berkeley National Laboratory in California, USA, have discovered that nanocrystals of germanium embedded in silica glass don't melt until the temperature rises almost 200 degrees Kelvin above the melting temperature of germanium in bulk. What's even more surprising, these melted nanocrystals have to be cooled more than 200 K below the bulk melting point before they resolidify. Such a large and nearly symmetrical "hysteresis" -- the divergence of melting and freezing temperatures above and below the bulk melting point -- has never before been observed for embedded nanoparticles.

It's great to see a new book about the periodic table and this one is written by Eric Scerri, a world authority on the periodic table!

Dr. Eric Scerri is a leading philosopher of science specializing in the history and philosophy of the periodic table. He is also the founder and editor in chief of the international journal Foundations of Chemistry and is a full-time lecturer at UCLA where he regularly teaches classes of 350 chemistry students as well as classes in history and philosophy of science. You can buy this book from our WebElements Amazon Store or our WebElements Amazon UK Store.

The Periodic Table: Its Story and Its Significance

The periodic table is one of the most potent icons in science. It lies at the core of chemistry and embodies the most fundamental principles of the field. The one definitive text on the development of the periodic table by van Spronsen (1969), has been out of print for a considerable time. The present book provides a successor to van Spronsen, but goes further in giving an evaluation of the extent to which modern physics has, or has not, explained the periodic system. The book is written in a lively style to appeal to experts and interested lay-persons alike.

The Periodic Table begins with an overview of the importance of the periodic table and of the elements and it examines the manner in which the term 'element' has been interpreted by chemists and philosophers. The book then turns to a systematic account of the early developments that led to the classification of the elements including the work of Lavoisier, Boyle and Dalton and Cannizzaro. The precursors to the periodic system, like Döbereiner and Gmelin, are discussed. In
chapter 3 the discovery of the periodic system by six independent scientists is examined in detail.

Two chapters are devoted to the discoveries of Mendeleev, the leading discoverer, including his predictions of new elements and his accommodation of already existing elements. Chapters 6 and 7 consider the impact of physics including the discoveries of radioactivity and isotopy and successive theories of the electron including Bohr's quantum theoretical approach. Chapter 8 discusses the response to the new physical theories by chemists such as Lewis and Bury who were able to draw on detailed chemical knowledge to correct some of the early electronic configurations published by Bohr and others.

Chapter 9 provides a critical analysis of the extent to which modern quantum mechanics is, or is not, able to explain the periodic system from first principles. Finally, chapter 10 considers the way that the elements evolved following the Big Bang and in the interior of stars. The book closes with an examination of further chemical aspects including lesser known trends within the periodic system such as the knight's move relationship and secondary periodicity, as well at attempts to explain such trends.

Trace amounts of manganese is essential to human health. Now, a team of scientists from the University of Delaware, Scripps Institution of Oceanography, the University of Hawaii, and Oregon Health and Science University has found that a dissolved form of manganese, Mn(III), is important in waterways such as the Black Sea and Chesapeake Bay. It can keep toxic hydrogen sulfide (sulphide) zones in check.

The research is based on research conducted in 2003 that explored the chemistry of the Black Sea. Nearly 90% of the mile-deep system is a no-oxygen "dead zone," containing large amounts of naturally produced hydrogen sulfide (sulphide), which is lethal to most marine life. Only specialized microbes can survive in this underwater region.

Only carbon from the Group 14 elements forms stable double bonds with oxygen under normal conditions. When frozen, carbon dioxide is known as "dry-ice". A non-molecular single-bonded crystalline form of carbon dioxide (phase V) exists at high pressure.

Amorphous forms of silica (a-SiO₂) and germania (a-GeO₂) are known at ambient conditions but only recently has an amorphous, silica-like form of carbon dioxide, a-CO₂. This is labelled a-carbonia and made by compression of CO₂ at room temperature at pressures between 40 and 48 GPa (that's a staggering 400-500 thousand atmospheres).

An egg-shaped fullerene, or "buckyball egg" has been made and characterized by chemists in America at UC Davis (California), Virginia Tech, and Emory and Henry College in Virginia. They were trying to encapsulate terbium atoms within fullerenes but instead encapsulated terbium nitride within an egg-shaped fullerene.

The compound Tb₃N@C₈₄ was synthesized using an arc-discharge generator by vaporizing composite graphite rods containing a mixture of Tb₄O₇, graphite, and iron nitride as catalyst in a low-pressure He/N₂atmosphere. This gave a complex mixture of products and chromatography gave seven terbium-containing fractions, the fourth fraction of which contained two isomers of Tb₃N@C₈₄. Crystallographc studies show the compound from one angle in particular seems very egg shaped! Remarkable! The Tb₃N unit is clearly visible (terbium in green and nitrogen in blue).

Until the publication of this work it was normally accepted that no two pentagons can touch in a fullerene and are always surrounded by hexagons. However in this case there are two pentagons (the 8 atoms at the pointy part of the egg at the top of the attached image) linked as a bent pentalene fragment.

References

1. "Tb₃N@C₈₄: An Improbable, Egg-Shaped Endohedral Fullerene that Violates the Isolated Pentagon Rule", C.M. Beavers, T. Zuo, J.C. Duchamp, K. Harich, H.C. Dorn, M.M. Olmstead, and A.L. Balch, J. Am. Chem. Soc., 2006, 128, 11352.
2. UC Davis News Service

This is the start of the WebElements periodic table documentation

The BBC is airing some "periodic tales" on Radio 4. Familiar Radio 4 voices introduce elements from the Periodic Table and the unique roles they play in human existence - with a little help from the irreverent Tom Lehrer. Go here to listen in on these ten elements:

• Krypton: Heidli Nicklaus on the Superman element, krypton
• Helium: Brian Perkins dramatises the effects of Helium
• Silver: Trevor Harrison (Eddie Grundy in the Archers) finds some unusual properties of Silver
• Cobalt: Hedli Nicklaus (Cathy Perks) takes on the goblin element of cobalt
• Selenium: Carole Boyd (The Archers' Linda Snell) unearths selenium
• Oxygen: Brian Perkins bravely dramatises the effects of oxygen
• Arsenic: Charlotte Green takes on the deadly history of arsenic
• Mercury: Carole Boyd (Linda Snell) reflects on mercury, the poisonous liquid metal
• Iodine: Charlotte Green on the discovery of iodine's essential place in brain development
• Nickel: Trevor Harrison reveals that the space station Mir is largely made of nickel