Synthesis of Silyl–Molybdenum Complexes Connected by a 1,1′‐Metallocenylene Unit and Their Electrochemical Properties

Reactions of (mesityl)n(methyl)2-nsilylene complexes with pyridine-N-oxide (n = 1 and 0): formation of silanone complexes and a disiloxanyloxy complex

Silanones (OSiR2), a heavier congener of ketones (R2CO), are highly reactive species that are readily converted to oligomeric siloxane (O-SiR2)n. Coordination of silanones to the transition-metal fragments to afford silanone-coordinated complexes is a reliable silanone stabilization method. Recently, our group reported the synthesis, structures, and reactivity of dimesityl-substituted silanone complexes Cp*(OC)2M{OSiMes2(L)}(SiMe3) (M = W, Mo, L: Lewis base, Cp*: η5-C5Me5, Mes: 2,4,6-Me3C6H2). Herein, to investigate the effect of substituents on the silicon atom during the formation of a silanone complex, we demonstrated the use of Mes and smaller Me groups. As a result, the formation of Mes(Me)-substituted silanone molybdenum complex Cp*(OC)2Mo{OSiMes(Me)(py)}(SiMe3) (5b, py: pyridine) was suggested, the silanone tungsten complex Cp*(OC)2W{OSiMes(Me)(DMAP)}(SiMe3) (4a, DMAP: 4-(dimethylamino)pyridine) was obtained, and a dimethyl-substituted disiloxanyloxy(dioxo) complex Cp*(O)2W(OSiMe2OSiMe3) (9) was formed. The reaction of 4a with PMe3 proceeded via the elimination of DMAP and migration of the SiMe3 group to the oxygen atom of the silanone ligand to afford Cp*(OC)2W(SiMes(Me)OSiMe3)(PMe3) (11a). The Mo complex Cp*(OC)2Mo(SiMes(Me)OSiMe3)(PMe3) (11b) was produced by the reaction of Cp*(OC)2Mo{SiMes(Me)}(SiMe3) (7b) with pyridine-N-oxide in the presence of PMe3.

Synthesis and structure of a pyridine-stabilized silanone molybdenum complex and its reactions with PMe3 and acetone

The synthesis, structure and reactivity of a pyridine-stabilized silanone molybdenum complex are described.

Crystal structure of [N'-(2-hydroxy-4-methoxybenzylidene)-2-hydroxybenzohydrazido]( methanol)dioxomolybdenum(VI) methanol solvate, C16H16MoN2O7·CH3OH, C17H20MoN2O8

C17H20MoN2O8, triclinic, P1̅ (no. 2), a = 6.9004(7) Å, b = 10.225(1) Å, c = 14.332(2) Å, α = 79.346(2)°, β = 82.660(2)°, γ = 77.576(1)°, V = 966.4 Å3, Z = 2, Rgt(F) = 0.0318, wRref(F2) = 0.0813, T = 298 K.

Crystal structure of [N'-(3-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazido]( methanol)dioxomolybdenum(VI), C15H13BrMoN2O6

C15H13BrMoN2O6, monoclinic, P21/c (no. 14), a = 7.4143(3) Å, b = 18.7856(7) Å, c = 12.6319(5) Å, β = 104.463(1)°, V = 1703.7 Å3, Z = 4, Rgt(F) = 0.0262, wRref(F2) = 0.0680, T = 298 K.