A Triply Bonded Dimolybdenum Hydride Complex with Acid, Base and Radical Activity

Abstract

The triply bonded complex [Mo2Cp2(μ-H)-(μ-PCy2)(CO)2] (Cp = η5-C5H5) reacts readily at room temperature with a great variety of simple molecules, resulting in diverse processes, as illustrated by its reactions with CO (addition), CNtBu (insertion), and HSnPh3 (H2 elimination). This unsaturated hydride also easily incorporates 17e [MoCp(CO)3] or 16e [MnCp‘(CO)2] metal fragments to give 46e heterometallic clus-ters (Cp‘ = η5-C5H4Me).

Controlled nucleophilic activation of different sites in [Mo2Cp2L2(μ-SMe)2(μ-L′)]+ cations (L=ButNC, xylNC, CO; L′=SMe or PPh2)

“…It is, therefore, a 3e donor. This contrasts strongly with its mode of coordination in the only other structurally characterised formimidoyl dimolybdenum derivative, [Mo 2 Cp 2 (CO) 2 (l-Pcy 2 )(l-CHNBu t )] [12], where the C-N axis is perpendicular to the MoMo vector. These different orientations may be a result of orbital requirements but a steric interpretation appears more likely.…”

“…(a) Bond lengths in the (g 4 -C 5 H 4 R)-MoL(l-SMe) 3 units, L = CNPh (5), CO (12) Mo-L 2.005 (7) 2.043 (7) 1.951 ( (1) 2.755(1) C(6)-C (10) 1.442 (13) 1.409 (12) 1.516 (5) 1.518(5) C(6)-C (7) 1.438 (13) 1.442 (13) 1.534 (5) 1.528(5) C(7)-C(8) 1.445 (12) 1.414 (13) 1.402 (5) 1.403(5) C(8)-C(9) 1.426 (13) 1.436 (12) 1.444 (5) 1.456(5) C(9)-C(10)…”

“…2.223(4) and 2.096(4) Å ] than that of the corresponding bond in the isoelectronic diazenido species [Mo 2 Cp 2 (l-SMe) 3 (l-g 2 -N@NMe)] which has otherwise, apart from syn-SMe groups, a (1) 72.5 (1) Torsion angles (°) (1) 0.9 (4) {Mo 2 Cp 2 (l-SMe) 3 (l-g 2 -L)} core strikingly similar to that of 6 [11g]. The formimidoyl function in 6 also shows an interesting difference from other structurally characterised imino complexes [11][12][13]: it displays extensive delocalization of electrons along the Mo-C(4)-N(1) chain, as is evident from the sequence of distances 2.088(5) and 1.312(7) Å . The former distance is in the range for typical of Mo-C(carbenes) [14], while the latter indicates a C-N bond order of $1.5 [15].…”

Heterometallic clusters derived from the unsaturated carbyne-bridged dimolybdenum complexes [Mo 2 (η 5 -C 5 H 5 ) 2 (μ-CPh) (μ-PCy 2 ) (CO) x ] (x = 1, 2)

“…This is obviously due to reaction of 1 with the carbon monoxide generated by the photolytic process, and is in contrast with the behaviour of the related methoxycarbynebridged complex [Mo 2 Cp 2 (-COMe)(-PCy 2 )-CO)], which gave the trinuclear complexes [Mo 2 MnCp 2 L(-COMe)(-PCy 2 )CO) 4 ] under similar conditions [7]. In contrast, compound 1 reacts at room temperature with [Fe 2 (CO) 9 ], or with [Ru 3 (CO) 12 ] under visible-UV irradiation, to give the corresponding trinuclear clusters . This difference might be in part explained by the relatively important steric demands of the benzylidyne ligand, which might disfavour the approach of fragments needed for cluster formation, thus imposing a kinetic barrier to the reaction.…”

Reactivity of [CpMo(CO)2]2 towards heterocyclic thiols: Synthesis, structure, and bonding in the sulfido-ligated cluster Cp3Mo3(μ-CO)2(μ-κ2-C7H4NS)(μ-S)(μ3-S)

“…The solid-state molecular structure of the trimolybdenum cluster 3 is shown in Fig. 2 and selected bond distances and angles are listed in Table 2 [25] and Cp 3 Mo 3 (l 3 -CO) (CO) 4 (l-PCy 2 ) [26], but the absence of a ligating sulfido ligand(s) supports the existence of one Mo@Mo bond and the 46e count in these electronically unsaturated clusters.…”