Synthesis, structure and coordination of the ambiphilic ligand (2-picolyl)BCy2.

The new pyridine-borane compound (2-picolyl)BCy2, readily prepared from 2-picolyllithium and ClBCy2, adopts a head-to-tail dimeric structure in the solid state as indicated by X-ray diffraction analysis and according to NMR and DFT studies, the dimeric form equilibrates in solution with a strained monomeric structure; the ambiphilic behavior of the new compound is illustrated by its bridging coordination to the (p-cymene)RuCl2 unit.

Synthesis and theoretical study of a series of dipalladium(I) complexes containing the Pd2(mu-CO)2 core.

The complex [PBu4]2[Pd2(mu-CO)2Cl4] has been prepared in high yields by carbonylation of [PBu4]2[Pd2Cl6]. Methanol, potassium acetate, or CO readily reacted under ambient conditions to quantitatively afford a series of dipalladium(I) complexes, namely [Pd2(mu-CO)2Cl3(OCH3)]2-, [Pd2(mu-CO)2Cl3(OC(O)CH3)]2-, [Pd2(mu-CO)2Cl3(CO)]-, and [Pd2(mu-CO)2Cl2(OCH3)(CO)]-, all of which have the Pd2(mu-CO)2 core preserved. All these complexes have been characterized by infrared and NMR spectroscopies; the high nu(CO) stretching wavenumbers observed and the diamagnetic character of these complexes prompted us to perform theoretical calculations to describe the electronic structure of the Pd2(mu-CO)2 core and to gain an intimate description of the Pd-CO bonds.

Fluxionality and Isomerism of the Bis(dihydrogen) Complex RuH(2)(H(2))(2)(PCy(3))(2): INS, NMR, and Theoretical Studies.

To study the fluxionality of the bis(dihydrogen) complex RuH(2)(H(2))(2)(PCy(3))(2) (1), NMR spectra were recorded in Freons (mixture of CDCl(3), CDFCl(2), and CDF(2)Cl). 1 was found to remain fluxional at all temperatures, but the presence of CDCl(3) necessary for its solubilization induces its transformation into, first, RuHCl(H(2))(2)(PCy(3))(2) (3) and the new ruthenium(IV) dihydride RuH(2)Cl(2)(PCy(3))(2) (4). 4 is produced selectively in pure CDCl(3) but reacts further to give a mixture of chloro complexes.