Structure of (η⁶-C₆H₆)Mo(CO)₃ at room temperature and 120 K: motion about equilibrium and far from equilibrium

Abstract

The structure of (~76-benzene)tricarbonylmolybdenum, ('r/6-C6H6)Mo(CO)3, has been determined at room temperature and 120 K by single-crystal X-ray diffractometry. The molecular motion about equilibrium has been studied by means of thermal-motion analysis, showing that there is significant stretching motion of C6H 6 and CO relative to Mo. There are effects of molecular packing on the motion of the CO's and on the deviation of the molecular structure from C3,. symmetry which are mutually consistent. The motional features and the deviations from symmetry are very similar to those of the isostructural ('r/6-C6H6)Cr(CO)3 . The reorientational motion of the C6H 6 group has been explored by potentialenergy-barrier calculations within the atom-atom approach. The results are compared with the available solid-state spectroscopic information.('r/6-C6H6)Mo(CO)3 is monoclinic at room temperature [a = 6.162 (3), b = 11.096 (2), c = 6.826 (2)

Half-Sandwich Complexes of an Extremely Electron-Donating, Redox-Active η6-Diborabenzene Ligand

“…In each case, the metal sits slightly off-centre, with the bond distances to the ring carbon atoms adjacent to the bulky Dipp groups roughly 0.05 Å longer than those opposite. The distances from the ring centroid to the metal are essentially identical to those in the [(h 6 -C 6 H 6 )M(CO) 3 ] derivatives [21][22][23] and show the expected trend of Cr<W<Mo.…”

Intra- vs. intermolecular configurations in the three-legged, piano-stool compounds (o, m and p-xylene)Mo(CO)3

“…In the isomorphous structures of the (benzene)M(CO) 3 compounds Cr [10], Mo [11], W [12], they are perfectly staggered. In (toluene)M(CO) 3 , M = Cr is eclipsed [13] and M = Mo is staggered [14].…”

From Solid‐State Structure and Dynamics to Crystal Engineering

“…Straightforward examples are provided by the complex (C 6 H 6 )Mo(CO) 3 , shown in Figure , and by the carbonyl cluster (C 6 H 6 )Ru 3 (CO) 9 , shown in Figure , for which correlation between motion about and far from equilibrium position has been possible. See ref .…”

“…Based on the awareness of similarities and differences between organic, metal organic and inorganic systems, and their combinations, it was then possible to design new systems whereby the presence of charged species typical of the inorganic chemistry area could be exploited to reinforce intermolecular bonding as in the case of charge‐assisted hydrogen bonds, or to alter physicochemical properties as in the case of ionic cocrystals. On the other hand, the inherent difficulties in modelling solids containing both neutral and charged organic molecules as well as charged metals and their complexes, has made application of crystal structure prediction tools in inorganic crystal engineering a still far off objective. The shape of the (mainly) organometallic cation was also utilized to “mould” hydrogen bonded aggregation of organic systems to construct complex honeycomb like architectures or to aggregate inorganic anions in hydrogen bonded chains.…”