A 'two-in-one' crystal having two different dimensionality in the extended structures: A series of cadmium(II) coordination polymers from V-shaped organic linkers

Abstract

Three Cd(II) containing coordination polymers, formulated as {Cd(oba)(biip)}n·nH2O (1), {Cd(sdba)(biip)}n·n5H2O (2) and {[Cd1.5(hfipbb)2(biip)1.5(H2O)][Cd(hfipbb)(biip)]}n·n2H2O (3), have been synthesized by using ditopic V-shaped ligands i.e., H2oba (4,4′-oxydibenzoic acid), H2sdba (4,4ʹ-thiodibenzoic acid), H2hfipbb {4,4ʹ-(perfluoropropane-2,2-diyl)dibenzoic acid} and an auxiliary linker, biip {3,5-di(1H-imidazol-1-yl)pyridine} under solvothermal conditions. Compounds 1–3 are characterized by single crystal X-ray diffraction analysis, IR spectroscopy, thermogravimetric (TG) and elemental analyses. Compound 1 contains a 3D framework, formed by the connectivity of {CdO4N2} secondary building unit (SBU) with the organic linkers, whereas compound 2 is a 2D coordination polymer. Interestingly, unlike to compounds 1 and 2, compound 3 possesses a distinctive structural feature having two crystallographically independent polymeric motifs (polymers, A and B) having two different dimensionality within the same crystal, i.e., coordination polymer A (CP-A) that forms a one-dimensional motif and coordination polymer B (CP-B), which has a two-dimensional structure.