Investigating the Formation of Different (NH 4) 2 [ M (H 2 O) 5 (NH 3 CH 2 CH 2 COO)] 2 [V 10 O 28 ]· n H 2 O (M = Co II , Ni II , Zn II , n = 4; M = Cd II , Mn II , n = 2) Crystallohydrates.

Three hybrid compounds based on decavanadates, i.e., (NH₄)₂[Co(H₂O)₅(β-HAla)]₂[V₁₀O₂₈]·4H₂O (1), (NH₄)₂[Ni(H₂O)₅(β-HAla)]₂[V₁₀O₂₈]·4H₂O (2), and (NH₄)₂[Cd(H₂O)₅(β-HAla)]₂[V₁₀O₂₈]·2H₂O (3), (where β-Hala = zwitterionic form of β-alanine) were prepared by reactions in mildly acidic conditions (pH ~ 4) at room temperature. These compounds crystallise in two structure types, both crystallising in monoclinic P2₁/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(β-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(β-HAla)]₂[V₁₀O₂₈]·4H₂O (4) and (NH₄)₂[Mn(H₂O)₅(β-HAla)]₂[V₁₀O₂₈]·2H₂O (5) and spin states of [M(H₂O)₅(β-HAla)]²⁺ (M = Co²⁺, Ni²⁺, and Mn²⁺) cations in solution were confirmed by ¹H-NMR paramagnetic effects. FT-IR and FT-Raman spectra for 1–5 are in agreement with the X-ray structure analysis results. [ABSTRACT FROM AUTHOR]