Reactivity of [Cp*Mo(CO)₃Me] with chalcogenated borohydrides Li[BH₂E₃] and Li[BH₃EFc] (Cp*= (η⁵-C₅Me₅); E = S, Se or Te; Fc = (C₅H₅-Fe-C₅H₄))

Abstract

Reactivity of [Cp*Mo(CO)₃Me], 1 with various chalcogenide ligands such as Li[BH₂E₃] and Li[BH₃EFc] (E = S, Se or Te; Fc = (C₅H₅-Fe-C₅H₄)) has been described. Room temperature reaction of 1 with Li[BH₂E₃] (E = S and Se) yielded metal chalcogenide complexes [Cp*Mo(CO)₂(η²-S₂CCH₃)], 2 and [Cp*Mo(CO)₂(η¹-SeC₂H₅)], 3. In compound 2, {Cp*Mo(CO)₂} fragment adopts a four-legged piano-stool geometry with a η²-dithioacetate moiety. In contrast, treatment of 1 with Li[BH₃(EFc)] (E = S, Se or Te; Fc = C₅H₅-Fe-C₅H₄) yielded borate complexes [Cp*Mo(CO)₂(μ-H)(μ-EFc)BH₂], 4-6 in moderate yields. Compounds 4-6 are too unstable and gradual conversion to [{Cp*Mo(CO)₂}₂(μ-H)(μ-EFc] (7: E = S; 8: Se) and [{Cp*Mo(CO)₂}₂ (μ-TeFc)₂], 9 happened by subsequent release of BH 3. All the compounds have been characterized by mass spectrometry, IR, multinuclear NMR spectroscopy and structures were unequivocally established by crystallographic analysis for compounds 2, 3 and 7.