Structural resolution of the new polyoxometalate hybrid (C2N4H7O)4(NH4)[HMo7O24]·4H2O: Textile dye decolorization and BSA binding properties

Abstract

The hybrid organic-inorganic compound based on polyoxometalates, specifically (C₂N₄H₇O)₄(NH₄)[HMo₇O₂₄]·4H₂O (1) was synthesized under reflux conditions. The FT-IR spectroscopy, UV-Vis spectroscopy, and TGA-DTA analysis were utilized to investigate the physico-chemical properties of 1. Moreover, single crystal X-ray diffraction analyses revealed that the compound crystallizes in a monoclinic system with a C2/c space group. The lattice parameters are as follows: a = 43.1211(7) Å, b = 10.8198(2) Å, c = 17.1667(3) Å, β = 93.146(2)°. The crystal structure of 1 comprises a protonated heptamolybdate anion, protonated dicyandiamide (HPDCD) organic cations resulting from hydrolysis, one ammonium cation, and four lattice water molecules. Hydrogen bonding is instrumental in stabilizing the crystal network. The [HMo₇O₂₄]^5- anions, in conjunction with water molecules, form one-dimensional inorganic chains. The further assembly of these chains results in the formation of two-dimensional inorganic layers. Within these layers, both HPDCD cations and ammonium cations are incorporated. The overall three-dimensional structure of 1 constituted by alternating organic and inorganic layers. Hydrogen bonds were identified as predominant type of intermolecular interaction in the analysis of Hirshfeld surfaces fingerprint graphics. The newly developed hybrid material was employed to decolorize Novacron Blue EC-R textile dye. Optimal conditions for the decolorization process were established. The interaction between bovine serum albumin (BSA) and 1 was evaluated using steady-state fluorescence spectroscopy.