Structure of molecular adducts of inorganic salts. VIII. Thiourea complexes of cadmium nitrate

In the system Cd(NO3)(2)-tu-H2O, tu = thiourea, the structures of three Cd( NO3)(2) . ntu (n = 2, 4) addition compounds were carried out. Monoclinic Cd (NO3)(2) . 2tu, space group P2(1)/n, a = 4.267(1) Angstrom, b = 11.956(1) A ngstrom, c = 11.330(1) Angstrom, beta = 100.22(6)degrees. The crystal struc ture is built up of neutral [Mtu(2) . (NO3)(2)] centrosymmetric complexes. The two polymorphic modifications when n = 4 coexist under ambient conditio ns. They are both monoclinic, space group P2(1)/c, with cell parameters are a = 21.380(3) Angstrom, b = 5.975(1) Angstrom, c = 17.531(4) Angstrom, bet a = 122.56(2)degrees for (I) and n = 12.811(3) Angstrom, b = 9.157(1) Angst rom, c = 15.770(2) Angstrom, beta = 91.20(1)degrees for (II). Their structu res consist of complex [Mtu(4)](2+) cations and NO3- anions, linked through extensive networks of weak hydrogen bonds which hold the structural units together.