Isolation and Crystallographic Characterization of a Solid Precipitate/Intermediate in the Preparation of 5-Substituted 1H-Tetrazoles from Nitrile in Water

The reactions of 2-, 3-, and 4-cyanopyridine with NaN3 in the presence of H2O and Lewis acid (ZnCl2) afford discrete monomer, (2-PTZ)2Zn(H2O)2 (1), 3D diamondoid-like network (3-PTZ)2Zn (2), and 2D layered network (4-PTZ)Zn(OH)(H2O) (3), respectively (PTZ = 5-(pyridyl)tetrazolato).Their solid state structures and natures give new insight into the Sharpless reaction of 5-substituted 1H-tetrazole. Interestingly, 2 crystallizes in a noncentrosymmetric space group and its powdered sample is second-harmonic generation active.