Contributions to the Coordination and Structural Chemistry of Gallium(III) and Indium(III) Halides: Complexes with Bi- and Tridentate Tertiary Phosphanes

Abstract

The reactions of gallium and indium trihalides with 1,2‐bis(diphenylphosphanyl)benzene (DP) and bis[(2‐diphenylphosphanyl)phenyl]phenylphosphane (TP) lead to a variety of molecular and ionic complexes. Treatment of InCl3 with DP results in [(DP)2InCl2]+[InCl4]− (1). With InBr3 or InI3 molecular 1:1 complexes (DP)InX3 (2: X = Br, 3: X = I) and ionic 1:2 complexes [(DP)InX2]+[InX4]− (4: X = Br, 5: X = I) are obtained. With GaBr3 and GaI3 only the ionic complexes [(DP)GaX2]+[GaX4]− (6: X = Br, 7: X = I) are generated. According to single‐crystal X‐ray analyses the environment of the metal center is octahedral in the cation of 1, square pyramidal in 3, and tetrahedral in the cations of 5 and 7. The reactions of TP with GaI3 or InI3 afford ionic complexes [(TP)MI2]+[MI4]− (8: M = Ga, 9: M = In). As shown by 31P‐NMR studies and X‐ray analyses, TP acts as a bidentate ligand in both complexes. The central phosphorus atom is not engaged in coordinative bonding. The 31P resonances of all compounds appear at higher field as compared to the free ligand. This phenomenon calls for further investigations and a detailed theoretical treatment.

Lewis Acid Catalyzed Z to E Isomerization of 1,2-Bis(diphenylphosphino) ethene

“…Applications of the corresponding gallium trihalides are limited to only a few examples like the GaBr3-mediated methyl transfer between alkylsilanes and -siloxanes [3]. In the course of our studies of the reactivity of Group III metal halides controled by various Lewis-bases [4] we have now observed an olefin Z^E isomer ization induced by aluminium and gallium halides.…”

Coordination chemistry of the main group elements with phosphine, arsine and stibine ligands

“…28) which are the only forms isolated in the solid state, although in situ 31 P{ 1 H} NMR studies suggested other species may be present in solution in the presence of excess diphosphine. The structures of the cations are distorted by the small chelate bite of the diphosphine (<P-Ga-P ∼85 • ), and the distortions cause loss of the 71 Ga NMR resonances of the cations as a consequence of the increased electric field gradients and resulting fast relaxation [170,179] (Fig. 29) [170].…”

“…30) showing a distorted tetrahedral cation with the terminal -PPh 2 groups coordinated to the gallium. The central PhP is ∼2.9Å from gallium and incorrectly orientated for a third Ga-P bond to be present [179]. Unexpectedly the tripodal triarsine, MeC(CH 2 AsMe 2 ) 3 , produced three different types of complexes with gallium(III) halides, although all contain distorted tetrahedral gallium centres [182].…”

“…The corresponding reactions [232] with the diarsine o-C 6 H 4 (AsMe 2 ) 2 were generally similar, although the 1:1 adducts are neutral dimers [In 2 X 6 {o-C 6 [179,233].…”

Synthesis and structural characterization of gallium and indium complexes obtained from redistribution reactions of mixed chalcogen-imidodiphosphinate ligands

“…The solid state structure of 5 reveals a discrete ion pair formed by the cationic bis-chelate species [Ga{N-(SP i Pr 2 )(SeP i Pr 2 )-S, Se} 2 ] + containing a tetracoordinated Ga(III) center surrounded by four chalcogen donor atoms in a tetrahedral environment and the [GaCl 4 ] À anion. The central Ga(2) atom in the [GaCl 4 ] À anion has a distorted tetrahedral coordination sphere with common features to similar anions [9,10]. The chlorine atoms are disordered over two positions and due to the high symmetry of the molecule, the sulfur and selenium atoms are sharing the same position with an occupancy factor of 0.5 (Fig.…”