Organic salts; Proton conducting; Mechanochemistry; Powder neutron diffraction; Solventless synthesis; Manual grinding; Conductivity; Ea energy
Solventless mechanochemical synthesis by manual grinding was applied to grow organic proton conducting salts, imidazole-succinic acid (C3H4N2-HOOC(CH2)2COOH) and imidazole-glutaric acid (C3H4N2-HOOC(CH2)3COOH). This synthesis method induces crystallization and provides the phase-pure compounds. Both compounds crystalize into a triclinic unit cell with space group P-1. The compounds exhibit different electric conducting behavior and activation energies Ea comparing with the reported single crystals obtained from the solution method. The difference in conducting property can be related to intrinsic defects and structural disorder introduced by mechanochemical grinding. The present study shows that the mechanochemical method bears strong capability for tuning conductivities. The mechanochemical synthesis of organic salts also holds high potential for the actual industrialized large-scale production.