title: Computational study of multiple-decker sandwich and rice-ball structures of neutral titanium-benzene clusters.
abstract: Density functional theory calculations were applied to systematically and directly compare the relative energetic stability of multiple-decker sandwich and rice-ball structures for a variety of neutral Ti(m)Bz(n) clusters (m = 1-4, n = 1-5). Almost all structures favored the multiple-decker sandwich structure, as observed experimentally for early transition metals. The strength of each metal-benzene interaction averages 37 kcal/mol and remains relatively constant for sandwiches with three or more Ti atoms. The most stable smaller rice-ball structures did not have eta(6)-Bz bound to a single metal atom. Instead, the preferred coordination was having the plane of the benzene molecule parallel to a Ti(2) bond or a Ti(3) face, leading to some distortion of the benzene ring. The larger rice-ball structures, on the other hand, preferred to weaken the metal-metal bonds and retain eta(6)-Bz bound to a single metal atom, a structural motif shared with sandwiches.
authors.affiliation: Department of Chemistry, University of San Diego, 5998 Alcala Park, San Diego, California 92110, USA. jkua@sandiego.edu
authors.forename: Jeremy
authors.initials: J
authors.lastname: Kua
authors.forename: Keaton M
authors.initials: KM
authors.lastname: Tomlin
mesh_terms: D001554:Benzene / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D014025:Titanium; D001554:Benzene