Experimental da ta on ligand effects in the chemistry of main group elements are less extensive than in the coordination chemistry of transition elements. The relation between the donor properties of ligands L and the halogen ligands in tin(IV) complexes of the type SnHal 4 L 2 being often uncertain, we performed a systematic N Q R study of tin(IV) complexes of the type Alk„SnHal4_„L2 , where o...

The phase stability of group VB (V, Nb, and Ta) transition metals is explored by first-principles electronic-structure calculations. Alloying with a small amount of a neighboring metal can either stabilize or destabilize the body-centered-cubic phase relative to low-symmetry rhombohedral phases. We show that band-structure effects determine phase stability when a particular group VB metal is al...

Some plants can hyperaccumulate metal ions that are toxic to virtually all other organisms at low dosages. This trait could be used to clean up metal-contaminated soils. Moreover, the accumulation of heavy metals by plants determines both the micronutrient content and the toxic metal content of our food. Complex interactions of transport and chelating activities control the rates of metal uptak...

The influence of quenched disorder on the competition between ordered states separated by a first-order transition is investigated. A phase diagram with features resembling quantum-critical behavior is observed, even using classical models. The low-temperature paramagnetic regime consists of coexisting ordered clusters, with randomly oriented order parameters. Extended to manganites, this state...

We herein described the synthesis of several 3-benzyl-2,5-diarylselenophene derivatives in moderate to good yields using (Z)-benzylselenoenynes as starting material in carbocyclization reactions. The reactions were carried out under mild conditions using only t-BuOK as base, in the complete absence of transition metals or additives. The cyclized 3-benzyl-2,5-diarylselenophenes obtained in the c...

Many transition metal complexes accomplish or catalyze the oxidation of C H, O H, and other -bonds. Under aerobic conditions, metal complexes typically modulate an autoxidation radical chain. In anaerobic reactions, a metal complex can be the reactive species that attacks t c a r h s d ©

We report on a heterocircuit [2]catenane in which a reversible half-rotation of one ring about the other can be induced, and locked in place, by switching the coordination of the interlocked rings between Pd(II) and Co(III).

Recent computational studies of C-H bond activation at late transition metal systems are discussed and processes where lone pair assistance via heteroatom co-ligands or carboxylates are highlighted as a particularly promising means of cleaving C-H bonds. The term 'ambiphilic metal ligand activation' (AMLA) is introduced to describe such reactions.

A salt-elimination reaction between the neodymium monoiodide [Nd(L')(N'')(I)](2) [L' = Bu(t)NCH(2)CH(2){C(NCSiMe(3)CHNBu(t))}; N'' = N(SiMe(3))(2)] and K[FeCp(CO)(2)] affords the first complex with an unsupported 4f-3d metal-metal bond that is sufficiently stable to be isolated; the bond is identified as principally ionic in nature by DFT calculations.