title: The methanol-methanolate CH(3)OH...OCH3(-) bridging ligand: tuning of exchange coupling by hydrogen bonds in dimethoxo-bridged dichromium(III) complexes.
abstract: Two bis(mu-methoxo)dichromium(III) complexes, [L(Se)(2)Cr(2)(mu-OCH(3))(2)(CH(3)OH)(2)] 1 and [L(Se)(2)Cr(2)(mu-OCH(3))(2)(CH(3)OH)(CH(3)O)](-) 2, where L(Se) represents the dianion of 2,2'-selenobis(4,6-di-tert-butylphenol), have been reported to demonstrate the effect of hydrogen bonding on the exchange coupling interactions between the chromium(III) centers. The corresponding sulfur analogue of the ligand, i.e., 2,2'-thiobis(4,6-di-tert-butylphenol), also yields the analogous [L(S)(2)Cr(2)(mu-OCH(3))(2)(CH(3)OH)(2)] 3 and [L(S)(2)Cr(2)(mu-OCH(3))(2)(CH(3)O)(CH(3)OH)](-) 4, which exhibit similar exchange coupling parameters. An acid-base dependent equilibrium between 1 and 2 or 3 and 4 has been established by electronic spectral measurements.
authors.affiliation: Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
authors.forename: Tapan Kanti
authors.initials: TK
authors.lastname: Paine
authors.forename: Thomas
authors.initials: T
authors.lastname: Weyhermüller
authors.forename: Karl
authors.initials: K
authors.lastname: Wieghardt
authors.forename: Phalguni
authors.initials: P
authors.lastname: Chaudhuri