Four configurationally and conformationally related Zn(II) complexes with a tri- dentate ligand namely, N-(2-pyridylmethyl)-phenylalanine (Hpmpa), have been synthesized by hydrothermal reactions. [Zn(L-α-pmpa)2·H2O] 1: orthorhombic, space group P21212 with a = 15.1091(7), b = 16.2417(8), c = 5.9972(3) , V = 1471.70(12) 3, Z = 2, Mr = 593.97, Dc = 1.340 g/cm3, μ = 0.879 mm-1, F(000) = 620, Rint = 0.0205, R = 0.0450 and wR = 0.1578 for 3102 observed reflections with I > 2σ(I); [Zn(D-α-pmpa)2·2H2O] 2: orthorhombic, space group P21212 with a = 15.1023(6), b = 16.2516(7), c = 6.0024(2) , V = 1473.21(10) 3, Z = 2, Mr = 611.98, Dc = 1.380 g/cm3, μ = 0.882 mm-1, F(000) = 640, Rint = 0.0337, R = 0.0484 and wR = 0.1435 for 2408 observed reflections with I > 2σ(I); [Zn(L-β-pmpa)2] 3: monoclinic, space group C2/c with a = 27.8667(5), b = 5.60350(10), c = 19.9636(2) , β = 120.2210(10)o, V = 2693.66(7) 3, Z = 4, Mr = 575.95, Dc = 1.420 g/cm3, μ = 0.955 mm-1, F(000) = 1200, Rint = 0.0345, R = 0.0358 and wR = 0.1135 for 2251 observed reflections with I > 2σ(I); and [Zn(D-β-pmpa)2] 4. They are all mononuclear discrete structures. The influence of temperature and pH on the conformation of structures has been investigated. Moreover, the photoluminescent properties of compounds 1 and 3 are also reported.
Two coordination polymers have been synthesized from cpg/4,4’-bipy/metal ions reaction system, [Zn(cpg)(4,4’-bipy)0.5(H2O)]?H2O 1 and [Cd(cpg)(4,4’-bipy)0.5(H2O)2]?H2O 2. X- ray analyses show that different coordination geometries of zinc and cadmium ions lead to similar ladder structures (tetra- for zinc ion and hexa- for cadmium ion), in which all the flexible cpg mole- cules exist as single conformations of anti-form.
