Syntheses and characterizations of three low-dimensional chloride-rich zincophosphates assembled about [d-Co(en)3]3+ and [dl-Co(en)3]3+ complex cations

Three new chloride-rich zincophosphates including two zero-dimensional (0D) clusters [dl-Co(en)(3)](2)[Zn-4(H2PO4)(2)(HPO4)(2)Cl-8] (denoted ZnPO-CJ33) and [d-Co(en)(3)](2)[Zn-4(H2PO4)(2)(HPO4)(2)Cl-8] (denoted ZnPO-CJ34), and one-dimensional (1D) zincophosphate chain [dl-Co(en)(3)][Zn-2(H2PO4)(HPO4)(2)Cl-2] (denoted ZnPO-CJ35) have been solvothermally prepared. ZnPO-CJ33 and ZnPO-CJ34 possess the same cluster structure as the macroanionic [Zn4H6P4O16Cl8](6-) unit formed by alternation of ZnOCl3/ZnO3Cl and HPO4/H2PO4 tetrahedra but differ in the countercations. The racemic [dl-Co(en)(3)](3+) cations are located among the clusters of ZnPO-CJ33, whereas chiral [d-Co(en)(3)](3+) cations are located among the clusters of ZnPO-CJ34. ZnPO-CJ34 templated by the optically pure chiral [d-Co(en)(3)](3+) cations is the first chiral monomeric zincophosphate. ZnPO-CJ35 templated by the racemic [dl-Co(en)(3)](3+) cations possesses a 1D infinite chain structure formed by the alternation of ZnO3Cl and HPO4/H2PO4 tetrahedra. The 1D chain structure of ZnPO-CJ35 can also be viewed as generated from the condensation of 0D clusters of ZnPO-CJ33, with the terminal Cl ions replaced by HPO4 groups. Experimentally, the structural transformation from ZnPO-CJ33 to ZnPO-CJ35 has been investigated.