Anion-dependent host-guest properties of porous assemblies of coordination complexes (PACs), [Cu(A)(2)(py)(4)] (A = PF6, BF4, CF3SO3, and CH3SO3; py = pyridine), based on Werner-type copper(II) complexes in the solid state

We report the syntheses and crystal structures of novel porous assemblies of coordination complexes (PACs) with/without guest molecules, alpha-[Cu(A)(2)(py)(4)] (alpha-PAC-2-A (A = PF6, BF4, CF3SO3, and CH3SO3); py = pyridine), gamma-{[Cu(PF6)(2)(py)(4)]center dot 2guest} (gamma-PAC-2-PF6 superset of 2guest (guest = acetone and py)), gamma-{[Cu(BF4)(2)-(py)(4)]center dot 2acetone} (gamma-PAC-2-BF4 superset of 2acetone), and beta-{[Cu(CH3SO3)(2)(py)(4)]center dot 2.67H(2)O} (beta-PAC-2-CH3SO3 superset of 2.67H(2)O). The single-crystal X-ray diffraction analyses of alpha-PAC-2-A show that alpha-PAC-2-A have dense packing structures, in which anions of the discrete coordination complexes form weak hydrogen-bonding and anion-pi interactions. In contrast, gamma-PAC-2-PF6 superset of 2guest, gamma-PAC-2-BF4 superset of 2acetone, and beta-PAC-2-CH3SO3 superset of 2.67H(2)O form guest-including structures with coordination environments around the Cu-II atoms similar to the a-forms. The vapour adsorption measurements for MeCN and acetone in alpha-PAC-2-A suggest that the adsorption associated with structural transformations is induced by weak Lewis-base PF6- and BF4- anions covered only with fluorine atoms, which weaken the host-host interactions.