Dioxotungsten(VI) Complexes with N2O Tridentate Ligands. Synthesis and Structure of the Chloro and Alkyl Derivatives

A new series of N2O tridentate ligands HLn (n = 2−5) have been prepared through N-methylation or N-benzylation of 2-N-(2-pyridylmethyl)aminophenol (HL1). Treatment of these ligands with WO2Cl2(DME) (DME = 1,2-dimethoxyethane) in the presence of triethylamine leads to the formation of cis-dioxotungsten(VI) complexes WO2(Ln)Cl (n = 1−5). Reaction of WO2(L1)Cl with Me3SiCH2MgCl gives the alkyl derivative WO2(L1)(CH2SiMe3), which has been structurally characterized.