High-temperature melt method is used to synthesize a novel class of bis-Betaines by taking 2-naphthol,methyl piperazine,and aldehyde with small steric hindrance as raw materials.The optimal synthesis conditions are identified as a 12-hour melt reaction at 120℃,followed by cooling to room temperature and treatment with 95%ethanol.The maximum yield of 73%is achieved.The synthesized bis-Betaine derivatives possess two chiral centers,which can be used as bridging ligands to form a series of new complexes with metal ions in coordination chemistry.The crystal structure and dielectric properties of the products are analyzed.The experimental results show that the compounds form supramolecular three-dimensional structures through intermolecular hydrogen bonding,crystallized in the monoclinic system,which remains stable in the studied temperature range without undergoing phase transitions.
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维普
