Synthesis and structural characterisation of cadmium(II) and zinc(II) coordination polymers with an angular dipyridyl bridging ligand:: parallel interpenetration of two-dimensional sheets with 4.82 topology

Coordination polymers formed between Cd(NO3)(2) or Zn(NO3)(2) and 2,4-bis(4-pyridyl)-1,3,5-triazine (dpt) have been synthesized and their single crystal structures determined. Reaction of a 1 & ratio;1 ratio of Cd(NO3)(2) with dpt in MeCN-CH2Cl2 affords the complex [Cd-2(NO3)(4)(dpt)(2)(MeCN)](infinity) 1 which exists as a doubly interpenetrated 4.8(2) two-dimensional sheet in the solid state. Each sheet is constructed from nitrate-bridged [Cd(dpt)](4) metallacycles. In sharp contrast the analogous reaction performed using a 2:1 L:M ratio affords the discrete molecular complex [Cd(NO3)(2)(dpt)(2)(MeCN)] 2 in which both dpt ligands act as terminal donors rather than bridging metal centres. Reaction of Cd(NO3)(2) with dpt in EtOH-CH2Cl2 affords a one-dimensional coordination polymer [Cd(NO3)(2)(dpt)(EtOH)](infinity) 3. Zn(NO3)(2) reacts with dpt in either a 1:1 or 2:1 L:M ratio to afford the one-dimensional polymer [Zn(NO3)(2)(dpt)](infinity) 4 which can be isolated as two polymorphs 4a and 4b which differ in their nitrate binding modes. The product formed is independent of the L:M ratio used in the reaction. Only 4a is formed when MeCN-CH2Cl2 is used as reaction solvent whereas both 4a and 4b are formed from either EtOH-CH2Cl2 or (PrOH)-Pr-i-CH2Cl2.