New class of salts containing different amino acids - an overview

Abstract A new class of amino acids salts containing different amino acids has recently been discovered: the present review reports about 69 such salts of eleven distinct types. The 38 salts crystallize in noncentrosymmetric space groups displaying nonlinear optical properties, 26 of them have polar symmetry and are potential pyro- or ferroelectrics. Single crystals of all these 69 compounds were obtained and their crystal structures were determined. 47 of them contain a dimeric cation of the [A(1) + ···A(2)] type, where A(1) and A(2) are different amino acids. The following 13 dimeric cations have been revealed: (Gly + ···Sar), (Gly + ···DMG), (Sar + ···DMG), (DMG + ···Sar), (Sar + ···Bet), (Bet + ···Sar), (DMG + ···Bet), (Bet + ···DMG), (L-Pro + ···Sar), ( β -Ala + ···L-Pro), ( β -Ala + ···Sar), ( β -Ala + ···DMG) and ( β -Ala + ···Bet). Among representatives of this class a new type of polymorphism was discovered. Some iodides among salts containing different amino acids can be used in medicine as regulators of thyroxine synthesis in the body.