Structural investigations of two 2‐amino‐5‐nitropyridinium Salts: C5H6N3ONO and (C5H6N3O)2CuCl

Through chemical preparations and crystal structures of the 2‐amino‐5‐nitropyridinium nitrate and the bis(2‐amino‐5‐nitropyridinium)tetrachlorocuprate, an attempt at polar crystal engineering using the 2‐amino‐5‐nitropyridinium cation and inorganic counter anions is illustrated. The role of the ratio of anion charge to dimension in the building of centric packings is illustrated and discussed. In the tetrachlorocuprate salt, distorted CuCl tetrahedral anions of D2d symmetry are present. C5H6N3O NO is monoclinic, P21/n, with a = 13.672(3), b = 7.762(1), c = 7.577(1) Å, β = 101.45(5)°, Z = 4, dx = 1.703. The crystal structure has been solved using 1 386 independent reflections with a final R value of 0.044. (C5H6N3O )2CuCl is monoclinic, P21/c, with a = 7.701(3), b = 31.99(5), c = 7.107(3) Å, β = 92.65(5)°, Z = 4, dx = 1.844. The crystal structure has been solved using 3 367 independent reflections with a reliability factor of 0.039.