Structural Diversity of <i>N</i> , <i>N</i> ′-Diarylbenzamidines and Highly Solvated H-Shaped Bisamidinium-Carboxylate Salt Crystals

Herein, we investigate the solid-state structure of N,N′-diarylbenzamidines in their neutral and cation states. Depending on the conditions, all three possible conformations were observed. Specifically, the E/Z form was observed in the neutral state, the sterically unfavorable Z/Z form was commonly observed in the halide salts, and the E/E form was dominant in the carboxylate salts because of the discrete salt bridge formation. The rigid H-shaped structure of the E/E form of bis(N,N′-diaryl)benzdiamidine created highly solvated crystals combined with carboxylic acids.