110296-11-2

Upstream product

• 700-12-9 pentamethylbenzene, 
• 7789-61-9 antimony(III) bromide 

Relevant academic research and scientific papers

?-Complexes of p-Block Elements: Synthesis and Structures of Adducts of Arsenic and Antimony Halides with Alkylated Benzenes

1,2,4,5-Tetramethyl- and pentamethylbenzene form stable 1:2 complexes with SbCl3 of the type (C6H6-nMen)*2SbCl3 (1,2) with an inverse sandwich structure.The compounds crystallize isotypically and are isostructural to the (hexamethylbenzene)antimony and -bismuth complexes.They are thus built of tetrameric chlorine-bridged Sb4Cl12 units, which are crosslinked at the metal centers with four other tetramers by double-sided arene coordination (X-ray structure analysis of 1).The Sb atoms, which are in a distorted trigonal bipyramidal environment, show a slight deviation from a centric (η6) coordination.The same stoichiometry and the same structural principle are found for the complex (C6Me6)*2AsCl3 (4), which is obtained from solutions of hexamethylbenzene and AsCl3 in toluene.In 4 the arsenic atoms are η6-coordinated to the hexamethylbenzene ring from both sides (X-ray analysis).Treatment of AsBr3 with hexamethylbenzene leads to a product of the composition 5(C6Me6)*AsBr3.Reaction of hexaethylbenzene with AsCl3 in petroleum ether leads to the formation of the 1:2 complex (C6Et6)*2AsCl3 (5), built of discrete inverse sandwich units, which are arranged in strings parallel to the crystallographic c axis.From solutions of AsCl3 (AsBr3), SbCl3 (SbBr3) and hexaethylbenzene in petroleum ether ternary compounds are isolated with an As:Sb ratio of 1:5.2 and 1:1.86, respectively.Single crystal X-ray structure determinations failed as a consequence of severe disorder.

Arene Complexes with an Inverse Sandwich Structure: The 1:2 Complexes of Hexamethylbenzene with SbCl3, SbBr3, BiCl3, and BiBr3

Hexamethylbenzene forms stable 1:2 complexes with SbCl3, SbBr3, BiCl3 and BiBr3 of the type X3E*C6Me6*EX3 (1-4) with an inverse sandwich structure.Crystals of the colourless antimony compounds and of the yellow bismuth compounds are isotypic (tetragonal, space group P42/nnm).The structures are built up of tetrameric units E4X12, which are crosslinked by double-sided arene coordination at each metal center E with four other tetramers, to give a three-dimensional organometallic polymer.While the Bi atoms in 3 and 4 are, to a first approximation, η6 coordinated to the aromatic hydrocarbon from both sides, the Sb atoms in 1 and 2 are shifted sidewise in opposite directions as projected onto the arene plane.The positions of the antimony atoms as well as those of the associated bridging halogen atoms in the lattice can be accounted for by a 50:50 disorder relative to the crystallographic symmetry elements.Isotypic complexes with pentamethylbenzene have also been obtained.