Polyoxometalates hydrophilic

K. Uehara, H. Nakao, R. Kawamoto, S. Hikichi, N. Mizuno, 2D-grid layered Pd-based cationic infinite coordination polymer/polyoxometalate crystal with hydrophilic sorption, Inorg. Chem. 45 (2006) 9448. 

As a consequence of showing that alkylated polyethyleneimines can facilitate aqueous biphasic catalysis, we extended the concept by the preparation of a cross-linked polyethyleneimine assembly that encapsulated a polyoxometalate catalyst, which resulted in the Upophiloselective oxidation of secondary alcohols (Scheme 9.17) [152]. Thus, even though reactions were carried out in water, competitive oxidation of a more hydrophobic alcohol in the presence of a hydrophilic alcohol significantly favored the former. The lipophiloselectivity was proportional to the relative partition coefficient of the substrates. 

Zhang J, Liu Y, Li Y, Zhao HX, Wan XH (2012) Hybrid assemblies of Eu-containing polyoxometalates and hydrophilic block copolymers with oihanced emission in aqueous solution. Angew Chem hit Ed 51 4598 1602. doi 10.1002/anie.201107481... 

Self-Assembly of Hydrophilic Polyoxometalate Macroanions in Dilute Solutions... 

FIGURE 2. Some large, hydrophilic polyoxometalate clusters. From left M0132, " Mo36s, Moi54, and Mo72Fe3o. Detailed molecular formulae are listed in Table 1. 

FIGURE 10. Mo72Fe3o A weak acid type of 2.5-nm diameter, Ceo-shaped spherical hydrophilic polyoxometalate molecular cluster formed by Mo-O polyhedrals (blue) and Fe-O polyhedrals (yellow). It can partially deprotonate the water ligands attached to its Fe centers (Reprinted with permission from ref. 21.)... 

In this volume we have collected 10 review chapters from distinguished scientists who have contributed extensively to the study and development of supramolecular assemblies that contain metals and metal-like elements with unusual structures and morphologies and possess potentially useful (and applicable) physical and biological properties. The first chapter by K. Ariga et al. is a general discussion of supramolecular structures that contain inorganic building blocks for hybrid lipid thin films, layer-by-layer assemblies, structure transcription, and functional mesoporous hybrids. This is followed by two chapters, the first by M. L. Kistler et al., who describe the self-assembly of hydrophilic polyoxometalate (POM) macro-anions and examine the structure and behavior of POM macro-ions in solution. This is followed by a chapter by S. K. Das, who provides an overview of the supramolecular features of POM-supported transition metal complexes, POM-crown ether complexes with supramolecular cations, and supramolecular water clusters associated with POMs. 

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