Synthesis, structures, and olefin polymerization capability of vanadium(4+) imido compounds with fac-N3 donor ligands

Helen R Bigmore; Martin A Zuideveld; Radoslaw M Kowalczyk; Andrew R Cowley; Mirko Kranenburg; Eric J L McInnes; Philip Mountford

doi:10.1021/ic060454i

Synthesis, structures, and olefin polymerization capability of vanadium(4+) imido compounds with fac-N3 donor ligands

Inorg Chem. 2006 Aug 7;45(16):6411-23. doi: 10.1021/ic060454i.

Authors

Helen R Bigmore¹, Martin A Zuideveld, Radoslaw M Kowalczyk, Andrew R Cowley, Mirko Kranenburg, Eric J L McInnes, Philip Mountford

Affiliation

¹ Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.

PMID: 16878953
DOI: 10.1021/ic060454i

Abstract

One-pot reactions of V(NMe2)4 with a range of primary alkyl- and arylamines RNH2 and Me3SiCl afforded the corresponding five-coordinate vanadium(4+) imido compounds V(NR)Cl2(NHMe2)2 [R = 2,6-C6H3(i)Pr2 (1a, previously reported), 2-C6H4(t)Bu (1b), 2-C6H4CF3 (1c), (t)Bu (1d), Ad (Ad = adamantyl, 1e)]. The crystal structures of 1b (two diamorphic forms) and 1c featured N-H...Cl hydrogen-bonded chains. Reaction of 1a-e with the neutral face-capping, N3 donor ligands TACN (TACN = 1,4,7-trimethyltriazacyclononane) or TPM [TPM = tris(3,5-dimethylpyrazolyl)methane] gave the corresponding six-coordinate complexes V(NR)(TACN)Cl2 (2a-e) and V(NR)(TPM)Cl2 (3a-e). The X-ray structures of 2b, 2c, 2d, 3b, 3c, and 3e were determined. When activated with methylaluminoxane, certain of the complexes V(NR)(TPM)Cl2 (3) formed moderately active ethylene polymerization catalysts, whereas none of the compounds V(NR)(TACN)Cl2 (2) were active.