Structuresof 2,2′-bis(dimethylamino)biphenyl and its monohydrobromide)

Abstract

In the context of ‘proton sponge’ systems, for the conformationally flexible biphenyl 1 the X-ray structure analysis as well as the basicity have been determined. 1 forms monoprotonated salts of which the structure of the hydrobromide 1a·BrX was solved. It contains a ‘proton sponge’-like N⋯H⋯N hydrogen bridge to which the 1000-fold increase of the basicity constant as compared to N,N-dimethylaniline is attributed.