Monomeric Gallium(III) Compounds Containing Three Different Ligands. Crystal and Molecular Structures of GaMeCl(acac) and GaCl[N(SiMe₃)₂](acac)

Abstract

Five monomeric gallium(III) compounds, each containing three different ligands, have been prepared by metathetical and/or ligand redistribution reactions and identified as single compounds in benzene solution and in the solid phase, as appropriate. These compounds include GaRCl(acac) (R ) Me, Et, Mes (mesityl, C 6 H 2 Me 3 ); acac ) 2,4-pentanedionato), GaCl-[N(SiMe 3 ) 2 ](acac), and GaMe[N(SiMe 3 ) 2 ](acac). X-ray structural studies of GaMeCl(acac) and GaCl[N(SiMe 3 ) 2 ](acac) confirmed the presence of the three different ligands bonded to gallium in these monomeric molecules. The related derivatives GaMeCl(hfac) and GaMesCl(hfac) (hfac ) 1,1,1,5,5,5-hexafluoropentanedionato) were also prepared and characterized, but these compounds slowly decomposed at room temperature.

Cyclopentadiene Elimination Reactions for the Preparation of Organoindium(III) Derivatives. Crystal and Molecular Structures of Me2In(acac), (Me3CCH2)2In(acac), (Me)(Me3CCH2)In(acac), and [Me2InNH(t-Bu)]2

“…Cryoscopic molecular weight studies in benzene solution suggest that the compound exists as an equilibrium mixture of species, because the degree of association decreased from 1.23 to 1.09 as the solution was diluted from 0.068 to 0.010 m . Thus, dimethylindium acaetylacetonate is very different from Me 2 Ga(acac),12a Et 2 Ga(acac),12a (mesityl) 2 Ga(acac),12a R 2 Ga(bdk) 12a (R = Me, Et, mesityl; bdk = tfac, hfac, tmhd), and other gallium(III) β-diketonate derivatives 12b. All of these gallium compounds are monomeric in the solid state and in benzene solution.…”

“…In contrast, a mixture of In(acac) 3 and Me 2 In(acac) did not undergo ligand redistribution at room temperature or after heating at 75 °C for 6 days. Even though no example of a gallium β-diketonate derivative bearing two different organic ligands has been characterized as a pure compound, other derivatives with multiple substituents such as (Me)(Cl)Ga(acac),12b (Et)(Cl)Ga(acac),12b (Mes)(Cl)Ga(acac),12b and [N(SiMe 3 ) 2 ](Cl)Ga(acac) 12b exist as single compounds.…”

Chemistry of Some Dihalogallium(III) β-Diketonate Derivatives. Crystal and Molecular Structures of GaCl2(acac), GaCl2(tmhd), and [trans-Ga(acac)2(THF)2+][GaCl4-]

“…In contrast, compounds with the 1,1, 1,5,5,5-hexafluoro-2,4pentanedionato ligand (hfac) decompose by undergoing ligand redistribution reactions to form Ga(hfac) 3 . 2 As dichlorogallium(III) β-diketonates, GaCl 2 (bdk), should be useful starting materials for the preparation of other unsymmetrically substituted compounds, our goal was to investigate their chemistry. However, to our surprise, the nature of gallium compounds with this simplest formula had not been defined when this research was initiated, but there were numerous reports about an oily or waxy material with the simplest formula AlCl 2 -(acac).…”

Towards Cationic Gallium Derivatives: Metallacycles from the Reactions of Organogallium Compounds with Tetraorganodichalcogenoimidodiphosphinates and a New N‐(Diphenylthiophosphinyl)thioureato Ligand

“…In addition, a small number of planar gallacycle rings have been structurally characterized as derivatives of β‐diketonate ligands. For example, four‐coordinate [GaCl 2 (bdk)]10 [bdk = (2,4‐pentanedionato), acac and (2,2,6,6‐tetramethylheptanedionato)], [GaMeCl(acac)]28 and [GaCl{N(SiMe 3 ) 2 }(acac)]28 all show planar six‐membered GaO 2 C 3 rings with O−Ga−O bite angles ranging from 96.1 to 99.3°. It is thus significant that in complex 6 replacement of one phosphorus atom by a carbon atom does not induce partial planarity in the ring.…”