An (1-adamantylimido)vanadium(V)-dialkyl complex containing a chelate alkoxo(imino)pyridine ligand, V(NAd)(CH2SiMe3)(2)(L) [2, Ad = 1-adamantyl, L = 6-OC(Me)(2)-2-{(2,6-(Pr2C6H3)-Pr-i)N=CMe}-C5H3N], has been prepared, and some reactions with (CF3)(2)(CH3)COH, (CF3)(2)CHOH, 2,6-Me2C6H3OH, and 2,6-Me2C6H3SH in C6D6 have been explored. Two alkyl groups in 2 take a trans form, as determined by the dichloride analogue V(NAd)Cl-2(L) (1), and no reaction took place or afforded a negligible amount of the product even if the CA solution containing 2 and PMe3 (13 equiv) or NHC [2.1 equiv, NHC = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] was heated at 80 degrees C for 72 h. The reaction of 2 with (CF3)(2)CHOH and (CF3)(2)(CH3)COH at 25 degrees C afforded intermediates V(NAd)(CH2SiMe3)(2)(L)[ROH] [R = CH(CF3)2, C(CF3)2(CH3)], and the resultant species were converted-to the original complex 2 if the mixed solutions were placed in vacuo (to remove volatiles). The reactions with ROH upon heating or by stirring for longer hours afforded the monoalkyl-alkoxo species V(NAd)(CH2SiMe3)(L)(OR) [R = CH(CF3)(2) (4), C(CF3)(2)(CH3) (5)]; complex 4 determined by X-ray crystallography has a distorted tetrahedral geometry around vanadium. It has thus been proposed that reactions of the dialkyl complex 2 with ROH proceeded via pentacoordinated intermediates formed by coordination of ROH, accompanied by dissociation of two neutral nitrogen donors in the chelate ligand.
