Role of Metals and Thiolate Ligands in the Structures and Electronic Properties of Group 5 Bimetallic-Thiolate Complexes.

Syntheses, structures, and electronic properties of group 5 metal-thiolate complexes that exhibit unusual coordination modes of thiolate ligands have been established. Room-temperature reaction of [Cp*VCl] (Cp* = η-CMe) with Na[B(SCHS)] led to the formation of [Cp*VO{(SCH)S}] (). The solid-state X-ray structure of shows the formation of six-membered l,3,5-trithia-2-vanadacyclohexane that adopted a chair conformation.

Heterometallic Triply-Bridging Bis-Borylene Complexes.

Triply-bridging bis-{hydrido(borylene)} and bis-borylene species of groups 6, 8 and 9 transition metals are reported. Mild thermolysis of [Fe (CO) ] with an in situ produced intermediate, generated from the low-temperature reaction of [Cp*WCl ] (Cp*=η -C Me ) and [LiBH ⋅THF] afforded triply-bridging bis-{hydrido(borylene)}, [(μ -BH) H {Cp*W(CO) } {Fe(CO) }] (1) and bis-borylene, [(μ -BH) {Cp*W(CO) } {Fe(CO) }] (2). The chemical bonding analyses of 1 show that the B-H interactions in bis-{hydrido (borylene)} species is stronger as compared to the M-H ones.

Stabilization of Classical [B H ] : Structure and Bonding of [(Cp*Ta) (B H )(μ-H)L ] (Cp*=η -C Me ; L=SCH S).

The room-temperature reaction of [Cp*TaCl ] with LiBH ⋅THF followed by addition of S CPPh results in pentahydridodiborate species [(Cp*Ta) (μ,η :η -B H )(μ-H)(κ ,μ-S CH ) ] (1), a classical [B H ] ion stabilized by the binuclear tantalum template. Theoretical studies and bonding analysis established that the unusual stability of [B H ] in 1 is mainly due to the stabilization of sp -B center by electron donation from tantalum. Reactions to replace the hydrogens attached to the diborane moiety in 1 with a 2 e {M(CO) } fragment (M=Mo or W) resulted in simple adducts, [{(Cp*Ta)(CH S )} (B H )(H){M(CO) }] (6: M=Mo and 7: M=W), that retained the diborane(5) unit.

Chalcogen stabilized trimetallic clusters: synthesis, structures, and bonding of [(Cp*M)(E)(BH)] (M = Nb or Ta; E = S or Se; m = 0 or 1 or 2; n = 0 or 1).

In an effort to isolate the chalcogen-rich niobium analogue of [(Cp*Ta)3(μ-S)3(μ3-S)3BH], the room temperature reaction of [Cp*NbCl4] (Cp* = η5-C5Me5) with Li[BH2S3] was carried out. Although the objective of isolating the niobium analogue was not achieved, the reaction yielded a homocubane-type cluster [(Cp*Nb)3(μ-S)3(μ3-S)3(μ-S)BH], 1, and a hexa-sulfido cluster [(Cp*Nb)3(μ-S)6], 2. Cluster 1 is a notable example of a homocubane-type cluster in which one of the vertices of the homocubane is missing.

Cyclometallation of a germylene ligand by concerted metalation-deprotonation of a methyl group.

The reaction of [CH{(CMe)(2,6-iPr2C6H3N)}2]GeCl with LiN(SiMe3)2 was previously reported, which led to the formation of a hetero-fulvene type germylene, [CH{(CMe)(C[double bond, length as m-dash]CH2)(2,6-iPr2C6H3N)}2]Ge through the deprotonation of the C-H bond from the methyl substituents. In this paper, we attempted the analogous reaction with (Dipp)NCMeCHCOMeGeCl using LiN(SiMe3)2 which gave rise to a metathesis product, (Dipp)NCMeCHCOMeGeN(SiMe3)2 (2). However, the reactions of 2 with [M2Cl2(μ-Cl)2(η5-Cp*)2] (M = Rh and Ir) resulted in cyclometallated Rh and Ir complexes through the activation of the C-H bond from the germylene ligand.