Molecule of the month

Three new monocyclic C₆H₆ isomers which are highly strained have been made in recent years.     

Molecule of the month

A novel way to isolate the highly reactive cyclobutadiene molecule is by trapping it inside a much larger molecule.     

Molecule of the month

The structure, properties and synthesis of a bowl shaped molecule, which resembles a fragment of fullerene, are described here.     

Molecule of the month

Electrochemical reduction of a cryptate yielded a neutral species with the properties of an expanded atom.     

Molecule of the month

The structure of a large and extremely toxic natural product is described.     

Molecule of the month

Studies on a highly strained hydrocarbon are discussed.     

Molecule of the month

A stable hexacationic benzene derivative has been prepared by the displacement of all the fluorine atoms of hexafluorobenzene by six molecules of 4-dimethylaminopyridine.     

Molecule of the month

Several facets of adamantane chemistry are highlighted.     

Molecule of the month

Reichardt’s dye A, shows spectacular solvatochromism having solutions coloured red in methanol, violet in ethanol, blue in isopropyl alcohol, green in acetone and greenish-yellow in anisole.     

Molecule of the month

Yellow crystalline mercurous nitrite was first reported by P C Rây¹ in 1896. In 1966, Allred et al reported that using Rây’s method, they had isolated the compound but that it turned into some ‘unidentified solid’ immediately. This resulted in a controversy that lasted four decades on whether it was possible to isolate mercury(I) nitrite or not. In 2011, A Chakravorty et al, on the 150th birth anniversary of Rây, delineated the synthesis as well as X-ray structural characterization of mercurous nitrite.     

Molecule matters

4-(N,N-dimethylamino)benzonitrile, popularly known as DMABN, has received tremendous attention for nearly five decades. In this article, we outline some of the features of the molecule that have made it such an interesting system to study, such as fluorescence emission in two wavelengths. The article also highlights how limited our understanding of the excited state structure of a small molecule like DMABN is, despite the availability of various resources to investigate it. Anunay Samanta is a professor of chemistry at the University of Hyderabad. Mainly he is interested in photophysics and time-resolved spectroscopy. Design of fluorosensors and study of photophysical response of molecular systems in ionic liquids are two of his current research topics of interest.     

Molecule matters

The first stable compound with a ‘quintuple bond’ reported recently is an exciting development that raises fundamental questions in theoretical and experimental chemistry.     

Molecule matters

The synthesis of a Fe^VI complex in an octahedral coordination geometry has been achieved recently by Wieghardt and coworkers. This is only the second hexavalent iron complex known after the tetrahedral ferrate ion, [FeO₄]^2?. The synthesis of the new Fe^VI complex involves a low temperature photolysis of an Fe^IV(N₃) precursor which leads to the formation of the Fe^VI complex containing a Fe≡N triple bond. The structural characterization of the Fe^VI complex has been achieved by a variety of spectroscopic techniques including Mössbauer spectroscopy and X-ray absorption spectroscopy. Experimentally it is found that the Fe^VI complex is diamagnetic. Theoretical calculations reveal that the Fe^VI complex has an electronic configuration 3d² (S = 0); the d electrons are paired in a d_xy orbital.     

Molecule matters

Carbon dioxide is a fascinating molecule; its gaseous, liquid, solid and even supercritical fluid states have unique properties and applications. The linear triatomic structure of carbon dioxide molecule with two carbon-oxygen double bonds is all too familiar. However a whole new world has been opened up by high pressure-high temperature experiments that effected the polymerization of this small molecule into a covalent network structure with carbon-oxygen single bonds. The crystalline and amorphous forms of carbonia are built up of linked tetrahedral CO₄ units.     

Molecule matters

Ever since its isolation in 1820, Quinine has played a crucial role in the development of organic chemistry, chemical industry and modern medicine. The total synthesis of quinine, widely regarded as an event of epochal importance was claimed by Woodward and Doering in 1945. This work, however, heavily relied on unsubstantiated literature reports and it appears that Woodward’s work fell short of a total synthesis of quinine. The first stereoselective total synthesis of quinine was accomplished only in 2001, by Stork, who incidentally is the originator of the concept of stereoselectivity in total synthesis. Naturally, this work has been attested as a landmark in organic synthesis by leaders in the field.