128363-70-2Relevant academic research and scientific papers
Static and dynamic structure of Ru3(CO)9(μ3-η2:η 2:η2-C6H6) at room temperature and 193 K
Braga, Dario,Grepioni, Fabrizia,Johnson, Brian F. G.,Lewis, Jack,Housecroft, Catherine E.,Martinelli, Marcia
, p. 1260 - 1268 (2008/10/08)
The solid-state structure of the cluster benzene complex Ru3(CO)9(μ3-η2:η 2:η2-C6H6) (1) has been determined at room temperature (RT) and 193 K (LT) by single-crystal X-ray diffractometry. 1 is monoclinic, space group P21, Z = 2, a = 9.027 (1) A?, b = 12.665 (2) A?, c = 9.049 (3) A?, β = 118.15 (2)° for RT and a = 8.985 (1) A?, b = 12.527 (2) A?, c = 9.011 (1) A?, β = 118.217 (9)° for LT. The benzene ligand shows a clear Kekule?-type distortion: "long" and "short" C-C bonds [1.45 (1), 1.40 (2) and 1.45 (1), 1.41 (1) A? for RT and LT, respectively] alternate within the C6H6 fragment, the short bonds being involved in the coordination to the metal atoms. The H atoms bend away from the metal frame [average bending 21.1° and 21.5° for RT and LT, respectively]. Insights into the structure and bonding in 1 are obtained by semiempirical Fenske-Hall calculations. The differences in solid-state structures between 1 and the osmium analogue Os3(CO)9(μ3-η2:η 2:η2-C6H6) (2) are discussed in terms of intermolecular packing interactions. The molecular motion about the equilibrium position of 1 is studied by means of thermal motion analysis, while potential energy barrier calculations within the atom-atom approach are used to show that neither intramolecular nor intermolecular potential energy interactions oppose the reorientational motion of the benzene fragment in the solid state.
