Azo dicarboxylates are not conjugated: X-ray crystal structure and theoretical calculations on di-t-butylazodicarboxylate

Dialkyl azodicarboxylates are highly reactive reagents useful for several well-known reactions in organic synthesis. X-Ray crystallography and theoretical calculations reveal the counter-intuitive fact that the NN and CO groups are almost orthogonal and therefore are not conjugated. The analogous azobis(amides) are planar.116