A blue luminescent di-2-pyridylamine cadmium complex with an unexpected arrangement of thiocyanate ligands: a supramolecular layered structure based on hydrogen bonds and π–π stacking interactions

X-ray crystal structure of [Cd(dpa)2(SCN)2] (dpa=di-2-pyridylamine) is refined in triclinic space group P-1 (no. 2) with a=7.1464(5) Å, b=9.4368(7) Å, c=18.5843(7) Å,α=77.318(8)°, β=81.487(8)°, γ=71.427(8)° and shows a novel unequivalent coordination of two SCN− and a layered structure built by two types of hydrogen bonding and π–π stacking interactions. The luminescence studies show strong blue photoluminescence in range 360–450 nm as a result of the π→π∗ transition on the dpa ligand.