Main group metal lone-pair⋯π(arene) interactions: a new bonding mode for supramolecular associations

Crystal structures of the heavier main group elements in low oxidation states have been evaluated for the presence of supramolecular elementIJlp)⋯π(arene) interactions that are structure-directing. It is revealed that when present, these interactions lead to zero-dimensional, binuclear aggregates but higher-nuclearity species are sometimes observed, with one-dimensional supramolecular chains of varying topology being prominent. By contrast, two-dimensional aggregation based on elementIJlp)⋯π(arene) interactions are rare. In summary, interactions of main group metal lone-pairs with aromatic rings are revealed as synthons capable of assembling molecules into supramolecular aggregates

Inverse coordination chemistry: A novel chemical concept

Inverse Coordination Chemistry: A Novel Chemical Concept presents the fascinating array of inverse coordination complexes, from monoatomic centres to those with organic molecules as centres, in a systematic manner with full-colour illustrative examples. This book is a timely and comprehensive introduction to this largely overlooked field of inverse coordination in inorganic chemistry

Serendipitous compositional and structural diversity in urotropine adducts of binary cadmium xanthates

Three new compounds, Cd(S2COMe)2(hmta) (1), Cd(S2COEt)2(hmta)0.5 (2) and Cd(S2COiPr)2(hmta) (3), have been isolated from a systematic study of adduct formation between Cd(S2COR)2, R=Me, Et and iPr, precursors and potentially polydentate hmta; hmta is urotropine (hexamethylenetetramine). The compounds have been characterised by a variety of spectroscopic techniques including a photoluminescence study in both solution and the solid-state, as well as by thermal methods. Crystallography shows 1 to have μ2-bridging hmta leading to a one-dimensional coordination polymer. This framework is essentially repeated in 2 but with a μ3-bridging hmta so that Cd(S2COEt)2 entities decorate the chain. By contrast, a binuclear zero-dimensional aggregate with terminally bound hmta is found in 3. The influence of steric bulk of the alkyl substituents in Cd(S2COR)2 is pivotal in determining the ultimate structural outcome

{4-Phenyl-1-[1-(1,3-thia­zol-2-yl)ethyl­idene]­thio­semicarbazidato}{4-phenyl-1-[1-(1,3-thia­zol-2-yl)ethylidene]­thio­semi­carbazide}nickel(II) chloride mono­hydrate

In the title compound, [Ni(C12H11N4S2)(C12H12N4S2)]Cl·H2O, the NiII ion is chelated by two 2-acetyl­thia­zole-3-phenyl­thio­semicarbazone ligands, forming a distorted octa­hedral complex. The metal ion is coordinated via the thia­zole nitro­gen, imine nitro­gen and thione sulfur atoms from each thio­semicarbazone ligand, and two coordinating units lie almost perpendicular to each other give dihedral angle = 81.89 (1)°]. One thio­semicarbazone unit is found to bind a chloride anion through two hydrogen bonds, while the other is linked with the disordered crystal water molecule. Two mol­ecules are connected to each other through an inter­molecular N—H⋯S inter­action, forming a centrosymmetric dimer. Dimers are linked into sheets by π–π stacking of two phenyl rings [shortest C⋯C distance = 4.041 (3) Å]

Special features of the 9^9Be→\to2He fragmentation in emulsion at an energy of 1.2~A~GeV

The results of investigations of the relativistic $^9$Be nucleus fragmentation in emulsion which entails the production of two He fragments of an energy of 1.2~A~GeV are presented. The results of the angular measurements of the $^9$Be$\to$2He events are analyzed. The $^9$Be$\to^8$Be+n fragmentation channel involving the $^8$Be decay from the ground (0$^+$) and the first excited (2$^+$) states to two $\alpha$ particles is observed to be predominant.Comment: 10 pages, 6 figures, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 2005 (Author's translation