Phenazine-substituted polynuclear osmium clusters: Synthesis and DFT evaluation of the C-metalated derivatives Os3(CO)9(μ3,η2-C12H7N2)(μ-H) and Os3(CO)9(μ3,η2-C12H6N2)(μ-H)2

Experimental and computational preference for phosphine regioselectivity and stereoselective tripodal rotation in HOs3(CO)8(PPh3)2(μ-1,2-N,C-η1,κ1-C7H4NS)

“…We restricted our calculations to products where the two edge-bridging ligands share a common Os–Os vector due to their enhanced stability compared to isomers that contain two Os–Os bonds with a single edge-bridging ligand. 5 e ,21 And concerning the disposition of the PPh 3 group in HOs 3 (CO) 9 (PPh 3 )(μ-1,2-N,C-η 1 ,κ 1 -C 7 H 4 NS), we have examined only those isomers that possess an equatorial phosphine since axially disposed phosphine ligands experience an energetic penalty of 10–15 kcal mol −1 due to unfavorable van der Waals interactions between the phosphine and the pair of axial ligands on the adjacent osmium centers. 22 Not counting species D1, five additional structures exist with an equatorial PPh 3 ligand, and these are depicted in Fig.…”

Alkyne activation and polyhedral reorganization in benzothiazolate-capped osmium clusters on reaction with diethyl acetylenedicarboxylate (DEAD) and ethyl propiolate

“…Earlier calculations from our group have addressed ligand addition to related Os 3 clusters possessing a bridging benzylidene moiety, 36, 39 and these reports have demonstrated that the incoming ligand will add to one of the two originally metalated osmium centers. However, the possibility of a kinetically active cluster that contains an edge-bridging aryl moiety cannot be eliminated from consideration.…”