title: Dimethylalkoxygallanes: monomeric versus dimeric gas-phase structures.
abstract: The molecular structures of the vapors produced on heating dimethylalkoxygallanes of the type [Me(2)Ga(OR)](2) have been determined by gas electron diffraction and ab initio molecular orbital calculations. In the solid state [Me(2)Ga(OCH(2)CH(2)NMe(2))](2) (1) and [Me(2)Ga(OCH(2)CH(2)OMe)](2) (2) adopt dimeric structures, although only the monomeric forms [Me(2)Ga(OCH(2)CH(2)NMe(2))] (1a) and [Me(2)Ga(OCH(2)CH(2)OMe)] (2a) were observed in the gas phase. For comparison the structure of the vapor produced on heating [Me(2)Ga(O(t)Bu)](2) (3) was also studied by gas electron diffraction. In contrast to 1 and 2, compound 3 is dimeric in the gas phase, as well as in the solid state. The gas-phase structures of 1a and 2a exhibit five-membered rings formed by a dative bond between Ga and the donor atom (N or O) from the donor-functionalized alkoxide. In 3 there is no possibility of a monomeric structure being stabilized by the formation of such a dative bond since only a monofunctional alkoxide is present in the molecule.
authors.affiliation: Materials Chemistry Centre, Department of Chemistry, University College London, 20 Gordon Street, London, UK WC1H 0AJ.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Knapp
authors.forename: Derek A
authors.initials: DA
authors.lastname: Wann
authors.forename: Andrzej
authors.initials: A
authors.lastname: Bil
authors.forename: Julien T
authors.initials: JT
authors.lastname: Schirlin
authors.forename: Heather E
authors.initials: HE
authors.lastname: Robertson
authors.forename: Paul F
authors.initials: PF
authors.lastname: McMillan
authors.forename: David W H
authors.initials: DW
authors.lastname: Rankin
authors.forename: Claire J
authors.initials: CJ
authors.lastname: Carmalt