Synthesis and characterisation of infinite co-ordination networks from flexible dipyridyl ligands and cadmium salts

Crystallisation of flexible dipyridyl ligands with Cd(NO3)(2). 6H(2)O or CdSO4. 6H(2)O gives co-ordination networks of composition [Cd(NO3)(2)(Py2CH2)(2)] 1 [Py2CH2=1,1-bis(4-pyridyl)methane]; [Cd-2(NO3)(4)(Py2C3H6)(4)(H2O)] 2 [Py2C3H6=1,3-bis(4-pyridyl)propane]; [Cd-2(SO4)(2)(Py2C3H6)(3)(H2O)(2.7)]. 4.5H(2)O 3; [Cd(NO3)(2)(Py2C4H8)(H2O)(2)] 4 [Py2C4H8=1,4-bis(4-pyridyl)butane]; [Cd-2(NO3)(4)(Py2C5H10)(3)(H2O)] 5 [Py2C5H10=1,5-bis(4-pyridyl)pentane] and [Cd(NO3)(2)(Py2C6H12)(2)] 6 [Py2C6H12=1,6-bis(4-pyridyl)hexane]. The compounds were characterised by X-ray single crystal diffraction studies. In compounds 1, 2, 4 and 6 the cadmium ions are hexa-co-ordinate with a slightly distorted octahedral geometry. Compounds 3 and 5 both display examples of a less common hepta-co-ordinate cadmium ion geometry. Compounds 2, 3 and 6 exhibit novel modes of interpenetration.