Ligand mediated valence fluctuation of copper in new hybrid materials constructed from decavanadate and a Cu(1,10-phenanthroline) complex

Abstract

Two new organic hybrid materials [H4V10O28][CuCl(H2O)2(1,10-phenanthroline)]2·4H2O (V10O28-CuCl-phen) and [H4V10O28][Cu(H2O)3(1,10-phenanthroline)]2·4H2O (V10O28-CuO-phen) were synthesized at room temperature. The effect of the presence and absence of AlCl3 on the single crystal growth of the two compounds was studied. The compounds were characterized using single crystal X-ray diffraction (XRD), scanning electron microscopy, energy dispersive spectroscopy, infra-red spectroscopy and thermogravimetric analysis. XRD studies on selected single crystals suggest that the compounds consist of supramolecular 3D layer structures constructed from a tetra-protonated [V10O28] unit and the organometallic complex Cu(1,10-phen) with Cl and 2H2O molecules in the presence of AlCl3 in V10O28-CuCl-phen and with 3H2O molecules in V10O28-CuO-phen which was confirmed by TGA studies. Both compounds crystallize in the triclinic space group P1[combining macron]: a = 8.3886(3) Å, b = 10.4266(4) Å, c = 13.5860(5) Å, α = 92.440(2)°, β = 92.315(2)°, γ = 98.160(2)° for V10O28-CuCl-phen and a = 8.3733(5) Å, b = 10.4132(6) Å, c = 13.5904(8) Å, α = 92.295(4)°, β = 92.331(2)°, γ = 98.086(4)° for V10O28-CuO-phen. Magnetic measurements suggest that Cu exists in magnetic +2 oxidation state in V10O28-CuCl-phen and non-magnetic +1 oxidation state in V10O28-CuO-phen.

Decavanadate Salts of Cytosine and Metformin: A Combined Experimental-Theoretical Study of Potential Metallodrugs Against Diabetes and Cancer

“…200°C. This thermal behavior has been observed for other polyoxometalates ions with organic moieties (Iyer et al, 2014 ; Sánchez-Lombardo et al, 2014 ; Martin-Caballero et al, 2016 ; Dissem et al, 2018 ). Considering that the melting point of Metformin hydrochloride is 224°C (Benmessaoud et al, 2016 ), we can assign the endothermic peaks observed in the DTA thermogram in a temperature range of 190–210°C, to the melting of Metforminium cations (HMetf) present in Compound 2 .…”

Synthesis of Metforminium(2+) Decavanadates – Crystal Structures and Solid‐State Characterization

“…[29] However, almost all studies have focused mainly on the decavanadate cluster itself, and there are only a few reports that discuss the linkages of the decavanadate anion with the organic ligands. [9,18,29] We believe that more accurate information about these interactions in the solid state could be helpful in the design and development of new compounds based on the decavanadate anion.…”

“…[9] Interestingly, inorganic and organic decavanadates have been used as building blocks [21] to generate supramolecular frameworks that exhibit wide structural diversity in one, two, or three dimensions (e.g., chains, [13,20,22] layers, [14,16,23] channels, [24] or 3D networks). [10,14,17,18] The formation of the supramolecular structure is strongly dependent on the solvent, [25] pH value, ionic strength, temperature, and nature of the counterions [13][14][15][16][17][18][19][20][21]26] used in the synthesis. In the last decade, the basicity of the oxygen atoms in the decavanadate cluster has been established, [27,28] and the type and strength of hydrogen-bond interactions for the seven types of oxygen atoms in the decavanadate cage with a range of cations and organic molecules has been reviewed recently.…”

“…Recently, hybrid materials,9 organic decavanadates, have been synthesized with the aim to understand their biological,10 magnetic,11 and optical properties 12. Organic ligands such as tetra‐ N ‐alkylammonium,13,14 tetra‐ N ‐butylammonium,15,16 imidazole,17 1,2,4‐triazole,17 1,10‐phenanthroline,18 cytosine,19 the dipeptide glycylglycine,20 and biguanide derivatives have been employed 8. The organic ligands allow the modulation of the structures and properties of the new hybrid materials on the basis of electrostatic and hydrogen‐bond interactions 9.…”

A Robust Open Framework Formed by Decavanadate Clusters and Copper(II) Complexes of Macrocyclic Polyamines: Permanent Microporosity and Catalytic Oxidation of Cycloalkanes

“…12 While the coordinative role of small polyoxovanadate clusters (e.g. [V4O12] 4-) toward transition-metal complexes has been long documented, 13 most of the decavanadatemetalorganic hybrids known at present consists in ionic compounds, 14 in which the structural stability simply relies on electrostatic forces and weak intermolecular interactions between the different components. Indeed, the first crystal structure involving metalorganic complex moieties covalently grafted at the surface of decavanadate anions was not reported until 2007, 15 and almost all compounds with such characteristics that have been prepared later on consist in either discrete decorated clusters 16 or mono-dimensional arrangements.…”