Poly(vinyl chloride) undergoes dechlorination in the presence of triethylsilane (EtSiH) and a catalytic amount of [CpZr(NPh)][CHB(CF)] (1 b) at 40-80 °C, with up to 91 % efficiency. Stoichiometric reactivity studies conducted on cyclohexyl chloride as a model suggest that 1 b dechlorinates PVC by initial chloride abstraction, followed by hydride transfer to the cationic PVC chain from EtSiH. Consumer items such as pipe fitting, vinyl disc or electric cable insulation undergo either dechlorination or hydrosilylation of the carbonyl-containing copolymer (polyvinyl acetate) or plasticizer (phthalate).
View Article and Find Full Text PDFWe report the synthesis of a new generation of phenoxy-amidine ligands based on an aryloxy moiety possessing an -linked trisubstituted amidine. The reaction of the phenol-amidine proligands with aluminum and zinc alkyls gave mono- or bis-ligated complexes depending on the metal/ligand ratio used. The solid-state structure of four proligands and thirteen Zn and Al complexes has been determined by X-Ray diffraction analysis.
View Article and Find Full Text PDFEthylene- and phenylene-bridged bis(salicylamidine) ligands have been readily prepared from ethylene or phenylenediamine and iminium chloride derivatives generated from ,-dialkylsalicylamides. The former, in its diprotonated form (FAlenH), reacts with AlMe to afford a zwitterionic dimethyldiphenoxyaluminate complex with the FAlen ligand monoprotonated and in a bidentate κ, fashion. A phenylene-bridged proligand behaves differently, yielding a neutral methylaluminum complex bearing a κ,,-coordinated FAlen ligand.
View Article and Find Full Text PDFTi-imido complex [TiCl(NBu)(BIPP)] [; BIPP = bis(iminophosphoranyl)phosphide ligand] reacts with terminal alkynes R-C≡CH (R = phenyl, isopropenyl, cyclopropyl, and 2-pyridyl) via P-P bond cleavage of the BIPP ligand. The resulting complexes [TiCl(NPN')(NPhPPh)] () contain a pincer-type NPN' phosphide ligand that incorporates the terminal alkyne and the imido ligand from complex . Complexes feature two chiral centers (Ti and P) with interdependent absolute configurations; thus, they are formed stereoselectively.
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