A new luminous hexacoordinated coordination polymer of cadmium(II) containing benzidine and dicyanamide as bridging units

A neutral hexacoordinated 2D coordination polymer [Cd(bnzd)(dca)2]n (1) [bnzd = benzidine and dca = dicyanamide] is prepared using a one-pot reaction of the building units and characterized. X-ray structural analysis reveals each cadmium(II) center to adopt a distorted octahedral geometry with a CdN6 chromophore bound by two N atoms of two different bnzd and two sets of double μ1,5 dca units affording a 2D sheet structure with a (4,4) topology. In the crystalline state, multiple intermolecular N―H⋯N hydrogen bonds result in a 3D network structure. 1 displays intraligand 1(π–π⁎) fluorescence in DMF solution at room temperature.

Graphical AbstractA new photoluminous μ1,5 dicyanamide bridged 2D coordination polymer with (4,4) topology of cadmium(II) in concert with benzidine has been synthesized and characterized. Formation of 3D supramolecular architecture by intra- and intermolecular N―H⋯N hydrogen bonding has been discussed.Figure optionsDownload as PowerPoint slideResearch Highlights
► A hexacoordinated polymer [Cd(bnzd)(dca)2]n [bnzd = benzidine] is isolated.
► X-ray study shows 2D layer structure via EE bridging motifs of both bnzd and dca.
► Thermogravimetric analysis shows its thermal stability and decomposition pattern.
► The compound is an example of luminous material.