Investigating the Formation of Different (NH4)2[M(H2O)5(NH3CH2CH2COO)]2[V10O28]•nH2O (M = CoII, NiII, ZnII, n=4; M = CdII, MnII, n=2) Crystallohydrates

Three hybrid compounds based on decavanadates, i.e., (NH4)(2)[Co(H2O)(5)(beta-HAla)](2)[V10O28]center dot 4H(2)O (1), (NH4)(2)[Ni(H2O)(5)(beta-HAla)](2)[V10O28]<middle dot>4H(2)O (2), and (NH4)(2)[Cd(H2O)(5)(beta-HAla)](2)[V10O28]center dot 2H(2)O (3), (where beta-Hala = zwitterionic form of beta-alanine) were prepared by reactions in mildly acidic conditions (pH similar to 4) at room temperature. These compounds crystallise in two structure types, both crystallising in monoclinic P2(1)/n space group but with dissimilar cell packing, i.e., as tetrahydrates (1 and 2) and as a dihydrate (3). An influence of crystal radii and spin state of the central atom in [M(H2O)(5)(beta-HAla)](2+) complex cations on the crystal packing leading to the formation of different crystallohydrate forms was investigated together with previously prepared (NH4)(2)[Zn(H2O)(5)(beta-HAla)](2)[V10O28]center dot 4H(2)O (4) and (NH4)(2)[Mn(H2O)(5)(beta-HAla)](2)[V10O28]center dot 2H(2)O (5) and spin states of [M(H2O)(5)(beta-HAla)](2+) (M = Co2+, Ni2+, and Mn2+) cations in solution were confirmed by H-1-NMR paramagnetic effects. FT-IR and FT-Raman spectra for 1-5 are in agreement with the X-ray structure analysis results.