From Infinite One-Dimensional Helix to Discrete CuII15 Cluster along with in Situ SN2 Ring-Cleavage of cis-Epoxysuccinic Acid: pH-Controlled Assemblies, Crystal Structures, and Properties

摘要: Two CuII coordination complexes {[Cu(ces)(H2O)2](H2O)0.5}n (1) and [Cu15(dhs)6(OH)6(H2O)10](H2O)20 (2) have been synthesized from cis-epoxysuccinic acid (cis-H2ces) perchlorate under different pH conditions (ces = cis-epoxysuccinate dhs 2,3-dihydroxysuccinate), fully characterized by IR spectra, elemental analyses, as well single crystal powder X-ray diffraction techniques. Notably, when the reaction was performed at above about 7.4, a one-dimensional (1-D) helical chain complex 1 is formed, whereas neutral isolated Cu15 nanocluster 2 generated value decreased to range of 6.6−7.3, being concomitant with in situ SN2 ring-cleavage cis-H2ces form (2S,3S)- (2R,3R)-H4dhs. Further, extended supramolecular architectures are constructed via secondary interactions both structures. The magnetic properties also studied detail, showing that an antiferromagnetic S 1/2 spins possesses a...