A hydrogen-substituted osmium stannylene complex: isomerization to a metallostannylene complex via an unusual alpha-hydrogen migration from tin to osmium.

An osmium complex bearing a terminal hydrogen-substituted stannylene ligand, Cp*((i)Pr(3)P)(H)Os=SnH(trip) (1) (trip = 2,4,6-triisopropylphenyl), has been prepared by stannylene extrusion, and the complex has been structurally characterized. Complex 1 coordinates Lewis bases and activates the O-H bonds of water and methanol. Most interestingly, 1 converts to the metallostannylene complex Cp*((i)Pr(3)P)(H)(2)OsSn(trip) (2) thermally or photochemically by what appears to be a radical process.

µ(2)-Iodido-bis-{dimeth-yl[methyl-bis(quinolin-8-yl)silanyl-κN,Si,N']platinum(IV)} tetra-kis(penta-fluoro-phen-yl)borate dichloro-methane 0.66-solvate.

The title complex, [Pt(2)(CH(3))(4)(C(19)H(15)N(2)Si)(2)I][B(C(6)F(5))(4)]·0.66CH(2)Cl(2), resulted from an attempt to synthesize a stable five-coordinate platinum species via ligand abstraction of a six-coordinate platinum precursor. However, dimerization occurred after ligand abstraction, thereby yielding the compound described in this study. The cation is a dinuclear Pt(IV) organometallic complex, in which the metal centers are bridged by an I(-) anion. Both metal centers display a coordination geometry close to octa-hedral, including cis-arranged quinoline ligands connected by Si atoms, which form Pt-Si bonds, two cis-methyl groups, and the bridging I(-) anion. In the crystal structure, voids between cations and anions are partially filled with an average of 0.66 mol-ecules of dichloro-methane solvent.

Substitution chemistry of MM quadruply bonded complexes (M = Mo or W) supported by the anion of 2-hydroxy-6-methylpyridine.

The compounds M(2)(mhp)(4), where M = Mo or W and mhp is the anion formed from deprotonation of 2-hydroxy-6-methylpyridine, are shown to react with carboxylic acids RCOOH to give an equilibrium mixture of products M(2)(O(2)CR)(n)(mhp)(4-n) where R = 2-thienyl and phenyl. The equilibrium can be moved in favor of M(2)(O(2)CR)(4) by the addition of excess acid or by the favorable crystallization of these products. The latter provides a facile synthesis of the W(2)(O(2)CR)(4) compound where R = 9-anthracene. Reactions involving 2,4,6-triisopropyl benzoic acid, TiPBH, yield M(2)(TiPB)(2)(mhp)(2) compounds as thermodynamic products. Reactions involving Me(3)OBF(4) (1 and 2 equiv.) yield the complexes Mo(2)(mhp)(3)(CH(3)CN)(2)BF(4) and Mo(2)(mhp)(2)(CH(3)CN)(4)(BF(4))(2), respectively. The latter compound has been structurally characterized and shown to have mirror symmetry with two cis mhp ligands: MoMo = 2.1242(5) A, Mo-O = 2.035(2) A, Mo-N(mhp) = 2.161(2) A, and Mo-N(CH(3)CN) = 2.160(3) and 2.170(3) A. Reactions involving Mo(2)(mhp)(3)(CH(3)CN)(2)(2+) and Mo(2)(mhp)(2)(CH(3)CN)(4)(2+) with (n)Bu(4)NO(2)CMe (1 and 2 equiv.) yield the complexes Mo(2)(mhp)(3)(O(2)CMe) and Mo(2)(mhp)(2)(O(2)CMe)(2) which are shown to be kinetically labile to ligand scrambling. Reactions between Mo(2)(mhp)(3)(CH(3)CN)(2)(+)BF(4)(-) (2 equiv.) and [(n)Bu(4)N(+)](2)[O(2)C-X-CO(2)](2-) yielded dimers of dimers [Mo(2)(mhp)(3)](2)(micro-O(2)C-X-CO(2)] where X = nothing, 2,5- or 3,4-thienyl and 1,4-C(6)H(4). Reactions between Mo(2)(mhp)(2)(CH(3)CN)(4)(2+)(BF(4)(-))(2) and tetra-n-butylammonium oxalate and terephthalate yield compounds [Mo(mhp)(2)bridge](n) which by MALDI-TOF MS are proposed to be a mixture of molecular squares (n = 4) and triangles (n = 3) along with minor products of [Mo(2)(mhp)(3)](2)(bridge) and Mo(2)(mhp)(4) that arise from ligand scrambling.