The first nitrosyl derivatives of high nuclearity carbonyl clusters: Synthesis and X-ray analysis of the [(Ph 3P) 2N] + salts of the anions [Os 10C(CO) 24(μ 2-NO)] − and [Os 10C(CO) 23(NO)] −

Abstract

The carbido dianion [Os 10C(CO) 24] 2− reacts with NOBF 4 in MeCN to give [OS 10C(CO) 24(μ 2-NO)] − ( 1) in which the nitrosyl ligand adopts a novel bonding mode bridging the wingtips of a “butterfly” indentation of metal atoms. The anion 1 undergoes rearrangement and CO loss in solution to give [OS 10C(CO) 23(NO)] − ( 2); the overall molecular geometry of 2 is close to that previously found for the dianion [Os 10C(CO) 24] 2− with the nitrosyl ligand bonded in a terminal fashion to the tetrahedral Os 10 metal skeleton. Crystals of the [(Ph 3P) 2N] + salt of 1 are triclinic, space group P 1 , with a 20.389(4), b 14.670(3), c 12.333(3) Å, α 99.55(3), β 94.43(3), γ 103.03(3)°, Z = 2, refinement of atomic parameters using 2699 absorption corrected data converged at R = 0.0952. The [(Ph 3P) 2N] + salt of 2 crystallises with one molecule of CH 2Cl 2 in the triclinic space group P 1 , with a 19.374(3), b 16.813(3), c 11.791(2) Å, α 85.00(3), β 101.81(3), γ 99.43(3)°, Z = 2, refinement of atomic parameters using 8736 absorption corrected data converged at R = 0.0943.