1,3,5‐Benzene Tricarboxylic Acid Based Cocrystals With Selective Semiconductivity via H‐coupled Charge Transfer

Abstract

AbstractTwo organic cocrystals, one (1) based on benzene 1,3,5 tricarboxylic acid (TMA) plus 4‐amino pyridine and another (2) based on benzene 1,3,5 tricarboxylic acid (TMA) plus urea is reported. Cocrystals 1 and 2 are fully characterized by single crystal X ray diffraction, NMR and IR spectroscopy. The single crystal X ray diffraction shows the intermolecular H‐bonding interaction between components of the pairs TMA‐TMA as well as TMA‐4 amino pyridine and TMA‐Urea molecules. The conductivity studies for the cocrystal 1 shows semiconducting behavior whereas cocrystal 2remain as insulator under the same experimental condition. Computational studies with theoretically optimized structures as well as experimental X‐ray structures of both the cocrystals reveal the origin of conductivity as the H‐atom coupled charge transfer through the intermolecular H‐bonding between TMA and 4‐amino pyridine in cocrystal 1.