Polymeric topologies in cadmium(II) dithiophosphate adducts of the isomeric n-pyridinealdazines, n = 2, 3 and 4

A series of crystal structures of adducts formed between cadmium dithiophosphate, Cd(S 2 P(OiPr) 2 ) 2 , and the isomeric n-pyridinealdazine ligands, n = 2, 3, and 4, are described. A centrosymmetric dimer is found in the 2:1 adduct with the 2-isomer, i.e. [Cd(S 2 P(OiPr) 2 ) 2 ( 2 -NC 5 H 4 C(H)=C(H)C 5 H 4 N-2) 0.5 ] 2 , in which the cadmium atom exists within a cis-N 2 S 4 donor set and the di-pyridyl-type ligand is tetradentate. By contrast, trans-N 2 S 4 donor sets for cadmium and regular bridging modes of coordination lead to polymers with a stepladder topology are found in the 1:1 adducts with the 3-and 4-isomeric ligands, i.e. [Cd(S 2 P(OiPr) 2 ) 2 (n-NC 5 H 4 C(H)=C(H)C 5 H 4 N-n)] ∞ , for n = 3 and 4. Differences in aggregation behaviour are related to the binding requirements of the n-pyridinealdazine ligands.