A new luminous end-to-end thiocyanato bridged heptacoordinated coordination polymer of lead(II) containing a tetradentate Schiff base

A new end-to-end thiocyanato bridged coordination polymer [Pb(enbzpy)(μ1,3-NCS)(NCS)]n (1) has been synthesized using a one-pot reaction of Pb(OAc)2.3H2O, tetradentate Schiff base N,N΄-(bis(pyridine-2-yl)benzylidene)ethane-1,2-diamine (enbzpy) and NH4NCS in MeOH solution at room temperature. Single crystal X-ray diffraction measurement reveals that each lead(II) adopts a pentagonal bipyramidal geometry with a PbN6S chromophore coordinated through four N atoms of enbzpy, two μ1,3-bridged N and S atoms and one terminal N atom of thiocyanates. In crystalline state, 1 forms a 2D honeycomb like (63) topology through S∙∙∙S interaction and the layers stack through face-to-face π∙∙∙π interaction giving rise to a 3D network. At room temperature DMF solution of 1 displays a high-energy intraligand 1(π-π*) fluorescence.