1,1- and 1,2-isomers of the diborane(4) compound B2{1,2-(NH)2C6H4}2 and a TCNQ Co-crystal of the 1,1-isomer

Abstract

The synthesis and X-ray crystal structures of the diborane(4) isomers 1,1-B₂{1,2-(NH)₂C₆H₄}₂ and 1,2-B₂{1,2-(NH)₂C₆H₄}₂ are described together with the results of quantum chemical calculations which shed light on their relative stabilities and degree of aromaticity. Spectroscopic data are also provided for both isomers of the 4-methyl aryl derivative. The compound 1,1-B₂{1-O-2-(NH)C₆H₄}₂ has also been prepared and structurally characterised but no evidence was obtained for the corresponding 1,2-isomer. The compound 1,1-B₂{1,2-(NH)₂C₆H₄}₂ forms a co-crystal with TCNQ, the structure of which is also reported.