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• 116926-17-1 {Cu₄Br₂{C₆H₃(CH₂NMe₂)2-o,o'}2} 
• 2767-47-7 dimethyltin dibromide 

Relevant academic research and scientific papers

Bis-ortho-chelated arylcopper compounds. Synthesis and X-ray crystal structure of Cu4Br2[C6H3(CH2NMe 2)2-o,o′2

A novel arylcopper(I) compound has been prepared from the reaction of lithiated C6H4(CH2NMe2)2-o,o′ with CuBr. An X-ray crystal structure determination on this new compound revealed it not to be [Cu{C6H3(CH2NMe2) 2-o,o′}] but its 1:1 CuBr adduct (Cu4Br2C24H38N4; orthorhombic; Pcab; a = 18.167 (3), b = 19.462 (3), c = 17.036 (2) ?; Z = 8). The determined molecular structure shows a highly asymmetric [Cu4{C6H3(CH2NMe2) 2-o,o′}2Br2] molecule containing four differently coordinated copper atoms. The copper atoms, which are all three-coordinate, are in a butterfly arrangement which is kept together by two bridging C ipso atoms of the aryl ligands [Cu-C distance 2.074 (5) ? (mean)] and two bridging bromine atoms [Cu-Br distance 2.397 (1) ? (mean)]. The Cu-Cu distances for the two adjacent C-bridged bonds are 2.412 (2) and 2.406 (2) ? and for the Br-bridged bonds are 2.429 (2) and 2.737 (2) ?. The coordination pattern of the CH2NMe2 side arms is such that each of the copper atoms is N-coordinated [Cu-N distance 2.176 (4) ? (mean)], thus making them all three-coordinate. Variable-temperature 1H NMR measurements in the temperature range 233-373 K show that this asymmetric structure is not retained in solution and that a more symmetric molecule is formed. These spectra also show the existence of complex fluxional processes. Reaction of [Li2{C6H3(CH2NMe2) 2-o,o′}2] with CuBr{P(OMe)3} afforded an arylcopper compound whose formulation based on elemental analysis and 1H NMR data is [Cu2{C6H3(CH2NMe2) 2-o,o′}Br{P(OMe)3}2].