On their best behavior: Three zirconium compounds with one-, two-, and three-dimensional structures have been successfully synthesized by the ionothermal approach. The 3D zirconium phosphate (see picture; F green, H white, O red, P pink, Zr yellow) exhibits high catalytic performance, with a cyclohexane conversion ratio of 32% and cyclohexanone selectivity of up to 83%.

In an attempt to synthesize novel zirconium phosphate materials, a series of syntheses have been performed in a deep eutectic solvent (DES), composed of tetrapropylammonium bromide (TPABr) and oxalic acid. As a result, this DES does not act as a template provider in reaction probably owing to the steric effects of the longer chains of the TPA cation, and only the α-Zr(HPO(4))(2)·H(2)O (α-ZrP) phase has been achieved. However, after organic amine was added to the initial reaction mixture in a normal way, the additives did act as a template to induce the zirconium phosphate framework. For example, with 1,4-dimethylpiperazine as an additive, a novel layered compound, [C(6)H(16)N(2)](0.5)Zr(H(0.5)PO(4))(2)·H(2)O (denoted as ZrPO(4)-DES8) was obtained. Its structure was determined from single-crystal X-ray diffraction (XRD) data and consists of zirconium phosphate layers with the protonated 1,4-dimethylpiperazine and water molecules in between. Interestingly, the two layered materials as additives in a liquid lubricant exhibit excellent friction behavior with higher load-carrying and antiwear capacities in comparison to typical lubricant additives such as MoS(2) and graphite, increase the P(B) value of the base oil by 27.2% and 8.5%, and decrease the wear scar diameter of the base oil by 43% and 36%, respectively. Scanning electron microscopy, XRD, and energy-dispersive X-ray spectrometry are used to investigate the lubricant behavior of those materials.

Since the discovery of the aluminophosphate family of molecular sieves, [1] many other elements have been incorporated into these structures to form microporous materials (for example, zincophosphates and zirconium phosphates) and the preparation of these types of solids continues to be the focus of a large body of work. Zirconium phosphates are especially interesting as they exhibit unique properties in the fields of photochemistry, [2] molecular and chiral recognition, [3] biotechnology, [4] and catalysis. [5] Zirconium phosphates with one-, two-, and three-dimensional connectivities are usually prepared using a solvothermal approach in water or organic solvents as the mother liquid. The nature of the interaction between the solvent and reacting species is undoubtedly critical, not only for control over the final crystal structure of the products, but also their crystal size and morphology, [6] both of which are important for synthetic chemists and materials scientists. Choosing the proper solvent is vital to the success or failure of the attempted syntheses.Ionothermal synthesis, a new method for the preparation of aluminophosphate molecular-sieve analogues [7][8][9][10][11][12][13][14] and other materials, [15][16][17][18] was developed in 2004 and has interesting features and potential advantages over the traditional method of molecular-sieve synthesis. For example, the cation of the ionic liquid can act both as the solvent and the structure-directing agent, and synthesis can take place at ambient pressure, eliminating safety concerns associated with high solvent pressures. As there are at least a million binary ionic liquids and potentially more than 10 18 ternary ionic liquids and eutectic mixtures, [7] compared to only about 600 molecular solvents used for solvent thermal synthesis, this preparative method offers many opportunities for the synthesis of new porous frameworks by selecting solvents with different organic groups. In contrast to the large and wideranging studies that have been undertaken on the hydrothermal synthesis of molecular sieves, ionothermal synthesis has only begun recently. Nevertheless, the work that has been done shows exciting possibilities for the preparation of hitherto unknown materials for improved preparation of previously synthesized materials and for mechanistic studies.To the best of our knowledge, no description of the synthesis of zirconium phosphate compounds by the ionothermal method exists in the literature. In an attempt to synthesize this kind of solid material, a series of syntheses in deep eutectic solvents (DES) have been carried out using HF, zirconium(IV) oxychloride, and H 3 PO 4 as initial reactants. The addition of fluoride in the form of HF is relatively wellknown in the synthesis of open framework materials, and helps to solubilize all the starting materials in the reaction solvent. [7,19] As a result, three different frameworks have been successfully synthesized in the present study. Two of these compounds are new phases with chain and layer framework str...

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Ionothermal Synthesis of Layered Zirconium Phosphates and Their Tribological Properties in MineralOil. -[C6H16N2]0.5Zr(H0.5PO4)2·H2O (I) is synthesized by reaction of ZrOCl2, H3PO4, HF, and 1,4-dimethylpiperazine in a deep eutectic solvent composed of (Pr4N)Br and oxalic acid (autoclave, 180°C, 3 d). Without the addition of 1,4-dimethylpiperazine, α-Zr(HPO4)2·H2O (II) is obtained. Compound (I) crystallizes in the monoclinic space group P2 1 /c with Z = 4 (single crystal XRD). Its structure consists of zirconium phosphate layers with the diprotonated 1,4-dimethylpiperazinium cations and water molecules in between. As additives in a liquid lubricant (I) and (II) exhibit excellent friction behavior with higher load-carrying and antiwear capacities in comparison to typical lubricant additives such as MoS2 and graphite. -(LIU, L.; CHEN, Z.-F.; WEI, H.-B.; LI, Y.; FU, Y.-C.; XU, H.; LI, J.-P.; SLAWIN, A. M. Z.; DONG*, J.-X.; Inorg.