Supramolecular Interactions between Inorganic and Organic Blocks of Pentacyanoferrate/Poly(4-vinylpyridine) Hybrid Metallopolymer

Abstract

The combination of organic and inorganic molecular building blocks gives rise to hybrid supramolecular materials showing properties from both chemical domains. This work presents the synthesis of metallopolymers made from poly(4-vinylpyridine) (P4VP) and pentacyanoferrate(II) at various polymer repeating unit/[Fe(CN)(5)](3-) ratios (py/Fe) and focuses on the influence of each block on the properties of the other. The solvatochromic shift of the [Fe(CN)(5)](3-) moiety was investigated as a function of the py/Fe ratio and the water molar fraction (X(H(2)O)) of the ethanol/water medium. Asymmetric solvation favoring ethanol was enhanced as the py/Fe ratio increased. The results lead to a modification of the well-established thermodynamical model for asymmetrical solvation and suggest the formation of water-rich domains within the polymer coils with a large number of [Fe(CN)(5)](3-) units. From the macromolecular perspective, the increase of [Fe(CN)(5)](3-) units resulted in higher values of intrinsic viscosity, which is rationalized by the increase of the polymer coil charge density and therefore the increase in hydrodynamic volume due to repulsive electrical forces. Evaluating the intrinsic viscosity of a sample with py/Fe = 25 in solvent mixtures with different water molar fractions, it was found that the hydrodynamic volume is maximized at intermediate X(H(2)O) values, where both the ethanol-soluble uncomplexed polymer block and the water-soluble [Fe(CN)(5)](3-)-pendant units can be suitably solvated, preventing coil shrinkage.

A Novel Synthetic Route for the Preparation of an Amorphous Co/Fe Prussian Blue Coordination Compound with High Electrocatalytic Water Oxidation Activity

“…The ν(CN ring ) band at 1595 cm −1 of pure P4VP shifted to 1600 cm −1 for [Fe(CN) 5 ] 3− -co-P4VP. 38,40,41 The same trend was also noted for the ν(CC ring ) band at 1413 cm −1 , which shifted to 1417 cm −1 . 38,40−42 The slight shift of the cyanide stretch to higher frequencies compared to the precursor (2031 cm −1 for [Fe-NH 3 ]) indicates successful substitution of the amino ligands with the P4VP group without effecting the oxidation state of the Fe centers.…”

“…38,40−42 The slight shift of the cyanide stretch to higher frequencies compared to the precursor (2031 cm −1 for [Fe-NH 3 ]) indicates successful substitution of the amino ligands with the P4VP group without effecting the oxidation state of the Fe centers. 38 Similarly, the shift to lower wavelengths observed in the absorbance band in UV−vis spectra also supports the formation of a metal polymer composite ( Figure S2). 37,38 Moreover, the high solubility of [Fe(CN) 5 -PVP] in water in contrast to P4VP suggests the formation of a charged polymeric species.…”

Visible light-driven water oxidation with a ruthenium sensitizer and a cobalt-based catalyst connected with a polymeric platform

“…The reaction with Co 2+ leads to a shi to higher frequency due to the formation of the Fe-CN-Co coordination mode. 25,34 XPS studies indicate an observable change in the binding energy of the Ru 3d 5/ 2 signal for [Ru-P4VP] compared with that of Ru(bpy) 2 Cl 2 as a result of the replacement of chloride groups with pyridyl ones. Ru 3d 5/2 signals are considered for comparison due to overlap of the Ru 3d 3/2 and C 1s signals (Fig.…”

Prussian Blue Films Produced by Pentacyanidoferrate(II) and Their Application as Active Electrochemical Layers

“…Another question is how isn is coordinated in complex, through the nitrogen or the carboxylic group. To solve this question, vibrational spectroscopy (FTIR) was used because the vibrational modes of the pyridine ring are sensitive to the coordination of Fe(CN) 5 3– group 24. Assignments were performed based on computational tools and are presented in detail in the Supporting Information.…”