Layered metal phosphates

Clearfield, A. and Costantino U. (1996) Layered Metal Phosphates and Their Intercalation Chemistry, in Comprehensive Supramolecular Chemistry (eds G. Alberti and T. Bein) Pergamon Elsevier Ltd Press, Vol. 7, pp. 107. 

Structures and Exchange Properties of Layered Metal Phosphate Hosts... 

Incorporation of M—— M Complexes into Layered Metal Phosphates... 

Our studies of layered metal phosphates has generously been supported by the National Science Foundation (CHE-9100532). 

The resulting MnS nanoparticles can be used as a phosphor in thin-lihn electroluminescence devices (Khaorapapong et al. 2009). The incorporation of CdS, ZnS, and/or PbS into mesoporous silica (Chen et al. 1998 Zhang et al. 2001 Gao et al. 2001), layered metal oxides (Shangguan and Yoshida 2002), and layered metal phosphate (Cao et al. 1991) has also been reported. 

Nef reaction. The layered metal phosphate is an active catalyst for the solvent-free synthesis of /3-nitro alcohols. 

Y-J. Liu and M. G. Kanatzidis, Postintercalative polymerization of aniline and its derivatives in layered metal phosphates, Chem. Mater., 7, 1525-1533 (1995). 

Some newer heterogeneous catalysts which have been found effective with H2O2 work at least partly by general acid catalysis. These include layered metal phosphates (e.g. Zr, Sn) used for aromatic hydroxylation, described in section 9.5. 

Layered metal phosphate hydrates, M(HP04)2-nH20 (M=Sn, Zr, Ti) (MP), are layered compounds with water molecules in the interlayer that show high proton conductivities [58,59]. Among these hydrates, Sn(HP04)2 H20 (SnP) shows a high and stable proton conductivity above 100°C [58]. 

Kawakami, Y. and Miyayama, M. 2006. Proton condncting properties of layered metal phosphate hydrates. Key Eng. Mater. 320 267-270. 

Multilayers of Diphosphates. One way to find surface reactions that may lead to the formation of SAMs is to look for reactions that result in an insoluble salt. This is the case for phosphate monolayers, based on their highly insoluble salts with tetravalent transition metal ions. In these salts, the phosphates form layer stmctures, one OH group sticking to either side. Thus, replacing the OH with an alkyl chain to form the alkyl phosphonic acid was expected to result in a bilayer stmcture with alkyl chains extending from both sides of the metal phosphate sheet (335). When zirconium (TV) is used the distance between next neighbor alkyl chains is - 0.53 nm, which forces either chain disorder or chain tilt so that VDW attractive interactions can be reestablished. 

Figure 5.8 Entrapment of metal complexes into layered zirconium phosphates, (a) Covalent attachment ofthe complex (b) the complex held in place by non-covalent interactions. Reproduced with permission from [64],...

Spherical particles of various metal phosphate particles can be prepared by precipitation using urea as a homogeneous precipitation agent. Surface-active agents, such as SDS and CTAC, are effective in preparation of uniform-size spherical particles. The formed spherical particles are amorphous and contain OH- and H20, except cobalt phosphate particles with layered structure. These panicles are agglomerates of primary particles, and have pores of different sizes ranging from ultramicropore to mesopore. 

Group (IV) metal phosphates and phosphonates, transition metal oxides (titanates, silicates, niobates, etc.), layered oxides, and double hydroxides (aluminum, magnesium, iron, etc.) are some of the inorganic compounds used as layered host ma-... 

The crystal structure of layered a-ZrP [10] shows that a layer of Zr(IV) ions are sandwiched between two layers of phosphate anions, producing a sheet of metal phosphate where the free hydroxyl of the phosphate is oriented perpendicular to the metal phosphate layers [15]. A schematic structure of a-ZrP is shown in Fig. 

One of the best finishes for firearm steel is phosphatizing (Parkerizing) but few manufacturers offer this finish other than if required for military or police markets. The process deposits a crystalline layer of phosphates on the metal surface by immersion in a bath of iron, zinc, or manganese dioxide and phosphoric acid. Of these, a manganese phosphate finish is preferred for military use. 

The 0-d nanoparticles can be nano-metal oxides (such as silica,1 titania,2 alumina3), nano-metal carbide,4 and polyhedral oligomeric silsesquioxanes (POSS),5 to name just a few the 1-d nanofibers can be carbon nanofiber,6 and carbon nanotubes (CNT),7 which could be single-wall CNTs (SWCNT) or multiwall CNTs (MWCNT) etc. the 2-d nano-layers include, but are not limited to, layered silicates,8 layered double hydroxides (LDH),9 layered zirconium phosphate,10 and layered titanates,11 etc. 3-d nano-networks are rarely used and thus examples are not provided here. 

The growing interest in other categories of nanoparticles, such as synthetic anionic layered silicates, CNTs, nano-oxides or -hydroxides, metallic phosphates, etc., has materialized either through the study of combinations of those nanoparticles with layered silicates or with metal hydroxides or phosphorus FRs. Such combinations are also detailed in Section 12.3. Nevertheless, for some combinations, interpretations of the possible interactions between components are sometimes missing or not completely detailed. 

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