Synthesis, characterization, and acceptor behavior of dichlorotris(2-t-butylphenoxo)niobium(V)

Abstract

The reaction of niobium pentachloride with three equivalents of 2-t-butylphenol in carbon tetrachloride afforded [NbCl2(OC6H4C(CH3)3-2)3]. The identity of the complex has been established by elemental analyses, molar conductance, molecular weight determination, IR, 1H, and 13C-NMR and UV-Vis spectral studies. Based upon these studies, a square–pyramidal geometry around niobium has been proposed. Thermal behavior of the complex has been studied by TGA and DTA. Acceptor behavior of [NbCl2(OC6H4C(CH3)3-2)3] toward Ph3P, Ph3As, Ph3PO, Ph3AsO, and an uncommon ligand arsenictrithiophenoxide As(SPh)3 allows the isolation of 1 : 1 addition compounds as shown by physicochemical, IR, and 1H-NMR spectral studies. The formation of [NbCl2(OC6H4C(CH3)3-2)3] · As(SPh)3 appears to be the first adduct of its class and suggests the suitability of As(SPh)3 as a ligand.