Miscellaneous dimensional coordination polymers and luminescence emission properties of cadmium(II)-pseudohalide complexes

Abstract

Two dimensional classes of coordination polymers: 2D catena-[Cd(Me3en)(µ1,5-dca)2] (1) and catena-[Cd(ampip)(μ1,1-N3)(μ1,3-N3)2] (2) and 1D catena-[Cd(pren)(μ1,1-N3)2] (3) and catena-[Cd(isq)2(μ1,3-NCS)2] (4) and catena-{[Cd6(Me3pipz-H)4(Me3pipz)2(μ1,3-NCS)12][Cd(NCS)6]‧6H2O} (5), where Me3en = N,N,N‘-trimethylethylenediamine, ampip = 1-(2-aminoethyl-piperidine, pren = N-(n-propyl)-ethylenediamine, isq = isoquinoline and Me3pipz = 1-(2-dimethylaminoethyl)-4-methylpiperazine, have been synthesized and structurally characterized. The degree of dimensionality and nuclearity were discussed in relation to the skeletal nature of the coligands and the bridging pseudohalides. The luminescence emission properties of the five complexes Cd(II) together with [Cd(TPA)(N3)2]‧H2O (6), [Cd6(TPA)4(µ1,1,3-N3)4(µ1,1-N3)6](ClO4)2·2H2O (7) and [Zn(TPA)(N3)2]‧H2O (TPA = tris(2-methylpyridyl)amine) were investigated in methanol solution. No detectable or weak FL emission was observed in 1–5 complexes. The FL emission enhancement (λex = 260 nm) in the visible region decreases in the order [Zn(TPA)(N3)2]‧H2O > [Cd(TPA)(N3)2]‧H2O (6) ≥ [Cd6(TPA)4(µ1,1,3-N3)4(µ1,1-N3)6](ClO4)2·2H2O (7) with a red shift in the FL emission of the Cd(II)-TPA compounds.