The structures, solvent-free synthesis and interconversions of the complexes [MCl2(CEAP)2] and their hydrogen-bonded salts [CEAPH]2[MCl4] {M=Zn, Co and Hg, CEAP=4-[N,N-bis(2-cyanoethyl)amino]pyridine}

Abstract

Discrete metal complexes, [MCl 2 (CEAP) 2 ] {M = Zn ( 1 ), Co ( 2 ) and Hg ( 3 ), CEAP = 4-[N,N-bis(2-cyanoethyl)amino]pyridine} and their hydrogen-bonded salts [CEAPH] 2 [MCl 4 ] {M = Zn ( 4 ), Co ( 5 ) and Hg ( 6 ), CEAPH = 4-[N,N-bis(2-cyanoethyl)amino]pyridium} were prepared using CEAP or CEAP·HCl ligands and metal chlorides (molar ratio = 2:1) by both solvent-thermal synthesis method and solvent-free method. The crystal structure and powder X-ray diffraction (PXDR) studies revealed that the discrete metal complexes 1 – 3 could be converted into their hydrogen-bonded salts 4 – 6 respectively by absorbing HCl vapor in solid-gas station and these salts except for 6 could be converted back to their corresponding discrete metal complexes by grinding with KOH in solid station. The discrete complexes [MCl 2 (CEAP) 2 ] {M = Zn, Co and Hg, CEAP = 4-[N,N-bis(2-cyanoethyl)amino]pyridine} and their hydrogen-bonded salts [CEAPH] 2 [MCl 4 ] were prepared. The interconversions of complexes and salts were studied. ► Solvent-free synthesis method was used to prepare the metal complex. ► The complexes have been characterized by single X-ray diffraction. ► Structural interconversions of complexes and hydrogen-bonded salts were studied.