Syntheses and structures of chalcogen-bridged binuclear group 5 and 6 metal complexes

Moulika Bhattacharyya (1) , Rini Prakash (1) , Chandan Nandi (1) , Monojit Ghosal Chowdhury (1) , Beesam Raghavendra (1) , Thierry Roisnel (2) , Sundargopal Ghosh (1)

1 IIT Madras - Indian Institute of Technology Madras
2 ISCR - Institut des Sciences Chimiques de Rennes

Syntheses and structural elucidations of a series of chalcogen stabilized binuclear complexes of group 5 and 6 transition metals have been described. Room temperature reaction of [Cp*CrCl](2) (Cp* = eta(5)-C5Me5) with Li[BH3(SePh)] afforded a Se inserted binuclear chromium complex, [(Cp*Cr)(2)(mu-Se2SePh)(2)], 1. In an attempt to make the analogous complexes with heavier group 6 metals, reactions of [Cp*MCl4] (M = Mo and W) with Li[BH3(SePh)] were carried out that yielded Se inserted binuclear complexes [(Cp*M)(2)(mu-Se)(2)(mu-SePh)(2)], 2 and 3 (2 M = Mo and 3 M = W) along with known [(Cp*M)(2)B5H9], 4a-b (4a M = Mo and 4b M = W). Similarly, the reactions of [Cp*NbCl4] with Li[BH3(EPh)] (E = S or Se) followed by thermolysis led to the formation of binuclear chalcogen complexes [(Cp*Nb)(2)(mu-E-2)(2)], 5 and 6 (5 E = S and 6 E = Se) and known [(Cp*Nb)(2)(B2H6)(2)], 7. All these complexes have been characterized by H-1 and C-13 NMR spectroscopy and mass spectrometry. The structural integrity of complexes 1, 3, 5 and 6 was established by the X-ray diffraction studies. The DFT studies further exemplify the bonding interactions present in these complexes, especially the multiple bond character between the metals in 1-3.

Mots clés: Chalcogen; binuclear complex; chalcogen-bridged

Domaines: Chimie de coordination

Moulika Bhattacharyya, Rini Prakash, Chandan Nandi, Monojit Ghosal Chowdhury, Beesam Raghavendra, et al.. Syntheses and structures of chalcogen-bridged binuclear group 5 and 6 metal complexes. Journal of Chemical Sciences, 2019, 131 (12), pp.123. ⟨10.1007/s12039-019-1703-9⟩. ⟨hal-02438549⟩