Organoelement Compounds with AlAl, GaGa, and InIn Bonds

Abstract

In the attempt to synthesize compounds with aluminum in a low oxidation state and an AI-AI bond, by the reduction of alkylaluminum halides with alkali metals, analogous to a Wurtz coupling, in general the deposition of elemental aluminum and the formation of the corresponding trialkylaluminum compounds is observed. Thus, tetrasubstituted dialuminum compounds R,AI-AIR,, apart from a few poorly characterized examples, were for a long time considered part of an unverified class of substances. Only with the sterically very highly shielded tetrakis[bis(trimethylsilyl)methyl]dialuminum did we achieve the synthesis of the first completely characterized organoelement compound with unlimited stability, which shows aluminum in the oxidation state + II and has an AI-AI bond. In the meantime, corresponding compounds for the elements gallium and indium have been obtained. With the simple access to tetrasubstituted dimeta1 compounds, a fascinating new research area has opened for preparative chemistry, in which the particular interest will naturally lie in the reactive properties of the metal-metal bond

“Crowned” Univalent Indium Complexes as Donors? Experimental and Computational Insights on the Valence Isomers of EE′X4 Species

“…The InÀIn bond lengths are found to range from 2.6726(7) and 2.725 (2) and are on the shorter end of the values reported (2.654 [35] -3.197 [36] ) in the Cambridge Structural Database (CSD); [37] most of these reported distances are for covalent diindane variants that have been reviewed previously. [38][39][40][41] It is worth noting that the InÀIn distances in 3-5 increase as the halogen atom becomes heavier; such an observation is consistent with the decreasing Lewis acidity of the InX 3 as X changed from Cl to Br to I. Finally, it is observed that the complexes features a slightly distorted to almost perfectly linear arrangements of the X-In-In moiety with angles ranging from 170.09(4) to 179.63 (10).…”

Structure and bonding of MCB5H7 and its sandwiched dimer CB5H6M–MCB5H6 (M=Si, Ge, Sn): Isomer stability and preference for slip distorted structure

“…In 1995, Hosmane and co-workers synthesized a novel class of compounds where the Ga-Ga bond is stabilized by two 2,4-dicarbo-nido-hexaborate 2À carborane ligands [7]. A few inorganic compounds with Ga-Ga bond such as Ga 2 Br 3 , [GaC(SiMe 3 ) 3 ] 4 and Ga 2 R 4 [R = (Me 3 Si) 2 CH, 2,4,6-iPr 3 C 6 H 2 and 2,4,6-(CF 3 ) 3 C 6 H 2 ] have been reported in the literature [21][22][23][24][25]. Multiply bonded Si in RSi"SiR has been studied by Sekiguchi et al [26][27][28][29][30][31][32][33].…”

Monovalent Group 13 Organometallic Compounds: Weak Association to Monomeric, Versatile Two-Electron Donors

“…There is currently an immense enthusiasm among chemists to stabilize low-valent, multiply bonded compounds containing low-coordinate elements from Groups 13,14,and 15. Especially the last few years have been an exciting period in which reports concerning the synthesis of several unusual compounds have appeared in the literature. To name a few, a) a tetrasila-1,3-butadiene, [1a] b) the first silaarene, [1b] c) compounds with unsupported Bi Bi [2a] and Sb Sb double bonds, [2b] d) silylium cations, [3a] e) a cyclotrigermenium cation with a 2pelectron system, [3b] f) an Al 77 cluster ion with concentric spheres of Al atoms, [4] g) compounds containing a discrete metal ± chalcogen double bond such as SnSe, [5] and h) multiply bonded species involving gallium [6] have been discovered.…”

“…[13] Even though it has long been believed that 3 is the most stable oxidation state for B, Al, and Ga, a number of divalent compounds of these elements have been reported; this topic has already been comprehensively reviewed by Uhl. [14] However, the developments in this area have been rather slow, and it was only in the beginning of the 1990s that reports concerning the isolation and unambiguous structural characterization of stable and discrete monovalent M I organometallic compounds of the lighter Group 13 elements started to appear in the literature.…”