Title
Bis(Azulene) "Submarine" Metal Dimer Sandwich Compounds (C10h8)(2)M-2 (M = Ti, V, Cr, Mn, Fe, Co, Ni): Parallel And Opposed Orientations
Abstract
The opposed and parallel structures for the binuclear bis(azulene) "submarine" sandwiches (C10H8)(2)M-2 (M = Ti, V, Cr, Mn, Fe, Co, Ni) have been optimized using density functional theory. The lowest energy (C10H8)(2)M-2 structures of the early transition metals Ti, V, Cr, and Mn have the azulene units functioning as bis(pentahapto) ligands to each metal atom similar to the azulene ligand in the long-known molybdenum carbonyl complex (eta(5),eta(5) -C10H8)Mo-2(CO)(6). The metal-metal bonds in these early transition metal structures have distances and Wiberg bond indices consistent with the formal bond orders required to give each metal atom an 18-electron configuration for the singlet structures and a 17-electron configuration for the triplet structures. For the later transition metals Fe, Co, and Ni, the lowest energy (C10H8)(2)M-2 structures contain pentahaptotrihapto azulene ligands with an uncomplexed C=C double bond, similar to that in the long-known iron carbonyl complex (eta(5),eta(3)-C10H8)Fe-2(CO)(5). The parallel (eta(5),eta(3)-C10H8)(2)M-2 (M = Fe, Co, Ni) structures contain metallocene subunits with their metal atoms at long nonbonding distances of 3.5-3.9 angstrom from the other metal atom, which is located between the azulene C-7 rings. Higher energy opposed (C10H8)(2)Fe-2 structures contain an unprecedented distorted eta(6),eta(4)-azulene ligand using six carbon atoms for bonding to one iron atom as a hexahapto fulvene ligand and the remaining four carbon atoms for bonding to the other iron atom as a tetrahapto diene ligand. (C) 2015 Wiley Periodicals, Inc.
Year
DOI
Venue
2016
10.1002/jcc.24013
JOURNAL OF COMPUTATIONAL CHEMISTRY
Keywords
DocType
Volume
azulene, sandwich compounds, metal-metal bonding, density functional theory, first row transition metals
Journal
37
Issue
ISSN
Citations 
2
0192-8651
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Hong-Yan Wang100.34
hui wang200.68
R. Bruce King302.03
Henry F Schaefer4227.18