Carbyne(dichloro) and carbyne(dichloro)hydrido osmium complexes from alkyne precursors

Abstract

The dichloro(dihydrido)osmium(iv) and dichloroosmium(ii) compounds 4 and 5, which contain the hemilabile chelating phosphinoester Pri2PCH,C0,Me 2 as ligand, react with alkynols HC-CCPh(R)OH (R = Me, Ph) to give the octahedral carbynedichloroosmium(ii) complexes 7 and 8 ; the related starting material 6 with Pri2PCH2CH2NMe2 3 as ligand on treatment with HC-CCPh20H yields a carbyne(dich1oro)hydrido compound, and with HC-CPh a vinylidene osmium(ii) derivative.

Synthesis, Spectroscopic Characterization, and Reactivity of the Unusual Five-Coordinate Hydrido−Vinylidene Complex OsHCl(CCHPh)(PiPr3)2: Precursor for Dioxygen Activation

“…The presence of two singlets in this spectrum suggests that for both 2a and 2b , the mutualy trans disposed phosphine ligands are equivalent. This indicates that C α , C β , and the substituents of the vinylidene group lie in a plane, which is perpendicular to the P−Os−P plane, in agreement with that observed by X-ray diffraction analysis in substituted vinylidene compounds containing two bulky phosphine ligands . The structure of 2 , therefore, is as that of the five-coordinate carbonyl complex OsHCl(CO)(P i Pr 3 ) 2 , with the vinylidene ligand in the position of the carbonyl group.…”

Formation of Derivative Carbyne Complexes from Tp‘(CO)2M⋮CCH3 (M = Mo, W)

“…Vinylcarbyne Formation. Vinylcarbyne complexes have been reported by a number of groups. , Most relevant here is the formation of vinylcarbyne complexes reported by Geoffroy (vide supra) . Complexes 8 − 10 containing an alcohol functionality can be considered intermediates on the path to vinylcarbynes similar to those described by Geoffroy (see eq 9).…”

Synthesis and Electrochemical Properties of C5H−Bridged Bimetallic Iron, Ruthenium, and Osmium Complexes

“…The symmetric nature of the C 5 H unit indicated by the solution NMR data is also reflected by the solid-state structure, which showed comparable Os−C(α) (1.943(8), 1.974(9) Å), C(α)−C(β) (1.24(1), 1.19(1) Å), and C(β)−C(γ) (1.39(1), 1.32(1) Å) bond distances. The average Os−C(α) distance of 1.958 Å is near the upper end of those in osmium allenylidene complexes (for example, CpOsCl(CCCPh 2 )(P( i -Pr) 3 ), 1.875(6) Å; [Os(C(CO 2 Me)CH 2 )(CCCPh 2 )(CO)(P( i -Pr) 3 ) 2 ]BF 4 , 1.947(6) Å; [(η 5 -C 9 H 7 )Os(CCCPh 2 )(PPh 3 ) 2 ] + , 1.895(4) Å), is shorter than those in osmium acetylide complexes, and is longer than those in the vinylidene complexes OsCl 2 (CCHPh)(P( i -Pr) 3 )(( i -Pr) 2 PCH 2 CH 2 NMe 2 ) and OsCl(CCHSiMe 3 )(CHCHSiMe 3 )(P( i -Pr) 3 ) 2 . The average C(α)−C(β) bond distance of 1.22 Å is near the lower end of those found for the osmium allenylidene complexes mentioned above 14-16 and is similar to those observed for osmium acetylide complexes .…”