Impact of confinement and interfaces on coordination chemistry: Using oxovanadate reactions and proton transfer reactions as probes in reverse micelles

Counterion Affects Interaction with Interfaces: The Antidiabetic Drugs Metformin and Decavanadate

“…Recently, studies of how vanadium compounds interact with interface model systems and traverse membranes [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] have shown that several anionic complexes readily penetrate the interfaces, [16,17,20,21,26] but large oxometalates such as V 10 reside away from a negatively charged interface and close to a positively charged interface, as expected. [19][20][21]23,24,27,28] Because counterions can affect the properties, a suitable counterion choice could poten-By using 51 V NMR spectroscopy, we found only small differences between the metformium and Na + decavanadate materials. However, by using IR spectroscopy, the decavanadate-metformin material was found to affect the water pool and water organization near the interface of the reverse micelles differently.…”

“…How vanadium compounds are transported in biological systems is a complex topic that has been investigated by focusing both on transport by proteins in the blood as well as transport across membranes. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]28,35] The complexity of this topic is exacerbated by the aqueous oxovanadate chemistry because multiple species, nuclearities, and protonation states exist under physiological conditions. The interaction of V 10 with interfaces has been investigated in cells as well as in simple model systems such as reverse micelles (RMs) prepared from an organic solvent, water, and a surfactant.…”

“…V 10 can exist with a charge of -6 to -3 depending on the protonation state of V 10 as the pH decreases from neutral to about 2. The reactions and pK a values for these species, V 10 O 28 6-, HV 10 10 ), are shown in Equations (1), (2), and (3). The V 10 system contains three types of vanadium atoms with different environments as shown in part a of Figure 1: two V atoms embedded in the center (V A ), and two pairs of four V atoms (V B and V C ) that are separated from the surface of the oxometalate only by oxygen atoms.…”

Hetero and lacunary polyoxovanadate chemistry: Synthesis, reactivity and structural aspects

“…One example of the use of these interactions is the investigation of reverse micelle environments using decavanadates as a probe of proton gradient in the system [8]. The distribution of decavanadates in the cell may be monitoring using 51 V NMR chemical shifts as a probe [9]. Hydrolytic activity of polyoxovanadates has been studied to model a DNA phosphodiester bond cleavage, and dynamic polyoxovanadate frameworks may allow for the interaction and incorporation of phosphodiester moieties into the polyoxovanadate skeleton [10].…”

Synthesis and characterization of fluoride-incorporated polyoxovanadates

“…Once decavanadates are placed in micelles, it may interact with hydrophobic or hydrophilic sites, under the condition with a limited amount of water [6][7][8][9]. In such a confined-space, the chemical equilibrium may lead to a different distribution with a new species in-between metavanadates and decavanadates.…”