The 1:1 Proton-Transfer Compounds of N, N -dimethyl-4-[( E)-2-(4-pyridinyl)vinyl]aniline with 3-Nitrophthalic and Perchloric acids.

The crystal structures of the 1:1 proton-transfer compounds of the dipolar donor-π-acceptor compound N, N-dimethyl-4-[( E)-2-(4-pyridinyl)vinyl]aniline ( 1), also named dimethylamino-stilbazole, with 3-nitrophthalic and perchloric acids, viz. ( E)-4-[4-(dimethylamino)styryl]pyridinium 2-carboxy-3-nitrobenzoate monohydrate ( 2) and ( E)-4-[4-(dimethylamino)styryl]pyridinium perchlorate ( 3) are described. A redetermination of the structure of the parent free base 1 at 100 K is also reported. The ( E)-4-[4-(dimethylamino)styryl]pyridinium ion exhibits slight whole molecule disorder in 2 and 3. Compound 2 is the first organic salt that contains the unusual monoanion of 3-nitrophthalic acid that is deprotonated at the 1-carboxyl group. Graphical Abstract: The crystal structures of the 1:1 proton-transfer compounds of the dipolar donor-π-acceptor compound N, N-dimethyl-4-[( E)-2-(4-pyridinyl)vinyl]aniline with 3-nitrophthalic and perchloric acids, viz. ( E)-4-[4-(dimethylamino)styryl]pyridinium 2-carboxy-3-nitrobenzoate monohydrate and ( E)-4-[4-(dimethylamino)styryl]pyridinium perchlorate are described.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]