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A new three-dimensional metal-organic polymer, [MnNa 2 (Hbtc) 2 (H 2 O) 3 ] (where btc = 1,2,4-benzenetricarboxylate), has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallized in the monoclinic space group C 2/ c , with cell parameters: a = 8.2349(10), b = 11.191(2), c = 22.837(3) Å, β = 100.193(10)°, V = 2071.3(6) Å 3 and Z = 4. In the three-dimensional structure of the compound, each Na and Mn atom is six-coordinate with distorted octahedral geometry. [ABSTRACT FROM AUTHOR]

A new ionic complex [Ni( meso-cth)][Cr(ox)2(bpy)](H2O)(ClO4) [ meso-cth = meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, ox = oxalato ainon, bpy = 2,2′-bipyridine] was prepared and its structure was determined. The complex was found to crystallized in monoclinic space group P2(1)/ n, with a = 13.6000(4) Å, b = 18.763(5) Å, c = 14.995(4) Å, β =106.958(5)°, V = 3659.9(17) Å3, and Z = 4. The structure consisted of cationic [Ni( meso-cth)]2+, anionic [Cr(ox)2(bpy)]−, and perchlorate anions; the cationic [Ni( meso-cth)]2+ and anionic [Cr(ox)2(bpy)]− units were related by weak coordination bonds and hydrogen bonds. [ABSTRACT FROM AUTHOR]

The use of nanobiocatalysts, with the combination of nanotechnology and biotechnology, is considered as an exciting and rapidly emerging area. The use of iron oxide magnetic nanoparticles, as enzyme immobilization carriers, has drawn great attention because of their unique properties, such as controllable particle size, large surface area, modifiable surface, and easy recovery. In this study, various gamma-Fe(2)O(3)/Fe(3)O(4) magnetic nanoparticles with immobilized proteases were successfully prepared by three different immobilization strategies including A) direct binding, B) with thiophene as a linker, and C) with triazole as a linker. The oligopeptides syntheses catalyzed by these magnetic nanoparticles (MNPs) with immobilized proteases were systematically studied. Our results show that i) for magnetic nanoparticles immobilized alpha-chymotrypsin, both immobilization strategies A and B furnished good reusability for the Z-Tyr-Gly-Gly-OEt synthesis, the MNPs enzymes can be readily used at least five times without significant loss of its catalytic performance: ii) In the case of Z-Asp-Phe-OMe synthesis catalyzed by magnetic nanoparticles immobilized thermolysin, immobilization Strategy B provided the best recyclability: iii) For the immobilized papain, although Strategy A or B afforded an immobilized enzyme for the first cycle of Z-Ala-Leu-NHNHPh synthesis in good yield, their subsequent catalytic activity decreased rapidly. In general, the gamma-Fe(2)O(3) MNPs were better for use as an immobilization matrix, rather than the Fe(3)O(4) MNPs, owing to their smaller particle size and higher surface area.