The Alkyne-Cluster Interaction: Structural, Theoretical, and Spectroscopic Study on the Parallel μ3-η2 Bonding Mode in Trinuclear Carbonyl Clusters of Ruthenium and Osmium

S. Aime, R. Gobetto, D. Osella, R. Bertoncello, G. Granozzi, V. Busetti

Research output: Contribution to journalArticlepeer-review

Abstract

The parallel μ3-η2alkyne-cluster interaction in compounds of formula H2M3(CO)9(RC2R’) (M - Ru, Os) has been studied by means of X-ray diffraction, 1H and 13C VT (variable temperature) NMR and UV-PES spectroscopy, and CNDO theoretical techniques. Crystals of H2Os3(CO)9(CH3C2CH3) belong to the monoclinic space group P21/n with unit cell dimensions of a = 14.538 (4) A, b = 13,004 (4) A, c = 9.817 (3) A, β = 100.17 (5)°, and Z = 4, Full-matrix least-squares refinement converged to R = 4.95% for 3223 unique reflections. Relevant interatomic distances (A): Os(1)-Os(2) = 3.016 (1), Os(1)-Os(3) = 2.763 (1), Os(2)-Os(3) = 2.858 (1), C(42)-C(43) = 1.434 (36), Os(1)-C(42) = 2.067 (24), Os(2)-C(43) = 2.198 (26), Os(3)-C(42) = 2,364 (28), Os(3)-C(43) = 2.263 (27). The small differences observed between the Os(1)-C(42) and Os(2)-C(43) distances are thought to reflect the charge imbalance on the metal atoms. The lowest energy dynamic process observed in the 13C NMR spectra is consistent with an oscillatory motion of the alkyne and of the hydride bridging the Os(1)-Os(2) edge (Ha) coupled with the edge hopping of the second hydride (Hb). Subtle electronic changes induced by different substituents on the alkyne cause remarkable differences in the 2JC,H coupling pattern between Ha and CO ligands. The results of CNDO calculations have been used for the interpretation of the UV-PE spectra and for discussion of the bonding scheme of the studied molecules.

Original languageEnglish
Pages (from-to)4004-4010
Number of pages7
JournalInorganic Chemistry
Volume25
Issue number22
DOIs
Publication statusPublished - 1986
Externally publishedYes

Fingerprint

Dive into the research topics of 'The Alkyne-Cluster Interaction: Structural, Theoretical, and Spectroscopic Study on the Parallel μ3-η2 Bonding Mode in Trinuclear Carbonyl Clusters of Ruthenium and Osmium'. Together they form a unique fingerprint.

Cite this