Magnetic properties and circular dichroism of 1D chains built from chiral mononuclear and non-chiral trinuclear Cu(II) complexes with α-aminocarboxylates

Coordination polymers Cu(L-Pro)(ClO4)(H2O)(2) (1) and Cu-3(Gly)(4)(H2O)(2)(NO3)(2) (2) were synthesized and characterized structurally. Compound 1 possesses the structure of 1D chain, where Cu(II) ions are linked by carboxyl-group in syn-anti conformation in equatorial-equatorial mode. Compound 2 is polymeric chain, consisting from trinuclear blocks Cu-3(Gly)(4)(H2O)(2)(2+). In each of these units Cu(II) ions are linked by carboxyl-group in the same way as in 1, while trinuclear units Cu-3(Gly)(4)(H2O)(2)(2+) are linked by NO3 ions, acting as the bridges between Cu(II) ions of neighboring trinuclear units. Circular dichroism properties of 1 were studied in solid state and solution. Magnetic measurements revealed that there were ferromagnetic exchange interactions between Cu(II) ions in 1 (J = + 1.22(1) cm(-1) for Hamiltonian (H) over cap = 2J Sigma iSiSi+1) and 2 (J = + 1.17(2) cm(-1) for Hamiltonian (H) over cap = 2J((S) over cap (1)(S) over cap (2) vertical bar (S) over cap (2)(S) over cap (3)) vertical bar mu(B)gH((S) over cap (1) vertical bar (S) over cap (2) vertical bar (S) over cap (3))). (C) 2010 Elsevier B.V. All rights reserved.