Syntheses, Crystal Structures and Properties of a Series of Helical Complexes Constructed by Flexible N,N′-Bis(3-pyridylmethyl)amine

Five helical coordination polymers {[Cu(Hbpma)(H2O)(4)}(2)(SO4)(3)center dot 3.5H(2)O}(n) (1), {[Ni(Hbpma)(H2O)(4)](4)(SO4)(6)center dot 10.75H(2)O}(n) (2), {[Mn(Hbpma)(H2O)(4)](SO4)(1.5)center dot 3H(2)O}(n) (3), {[Zn (Hbpma) (H2O)(4)](4)(SO4)(6)center dot 4H(2)O center dot 4CH(3)OH}(n) (4) and {[Cu (Hbpma)(2)(H2O)(2)](SO4)(2)center dot 9H(2)O}(n) (5) (bpma=N,N'-bis(3-pyridylmethyl)amine) were synthesized and structurally characterized. The single-crystal X-ray analyses indicate that complexes 1 similar to 4 crystallize in the one-dimensional chain structures and complex 5 shows the two-dimensional layer structure, in which the metal ions are bridged by the protonated bpma ligands. It is noted that the flexible bpma ligands with the trans-trans conformation lead to the pseudo-helical chains for complexes 1 similar to 2, the helical chains for complexes 3 similar to 4 and a helical layer for complex 5. The magnetic properties and the thermal behavior are investigated. CCDC: 966929, 1; 966932, 2; 966930, 3; 966931, 4; 1054736, 5.