Xianghua Yu

Syntheses of MO2 (M=Si, Ce, Sn) nanoparticles by solid-state reactions at ambient temperature

Abstract Nano oxides (SiO2, CeO2, SnO2) were successfully synthesized by solid-state reactions at ambient temperature. The nanoparticles were characterized by X-ray powder diffraction, TEM, BET, and TGA-DTA. The SiO2 particles were also investigated using IR spectra. Effects of calcination on the nanoparticles were studied in this paper. The solid-state reaction technique is a convenient, inexpensive and an effective preparation method of monodisperse oxide nanoparticles in high yield. The mechanisms of the formation of nano materials by solid-state reactions at ambient temperature were primarily investigated.

Formation of Aminoxy and Oxo Complexes from the Reaction of Nb(NMe2)5 with O2 and the Crystal Structure of Nb(NEt2)5

The reaction of Nb(NMe(2))(5) with O(2) gives three complexes: monomeric (Me(2)N)(n)Nb(eta(2)-ONMe(2))(5-n) (n = 3, 4) and dimeric (Me(2)N)(4)Nb(2)[eta(2)-N(Me)CH(2)NMe(2)](2)(mu-O)(2). Nb(NEt(2))(5) was prepared in a mixture of pentane and THF, leading to its purification and characterization by single-crystal X-ray diffraction. Unlike Nb(NMe(2))(5), which adopts a square pyramidal structure, Nb(NEt(2))(5) is a distorted trigonal bipyramid. The reaction of Nb(NEt(2))(5) with O(2) gives an insoluble white solid.

Reactions of thioether carboxylic acids with mercury(II). Formation and X-ray crystal structure of mercury(II) mercaptoacetate

Abstract Reactions of Hg(II) salts with thioether carboxylic acids o -C 6 H 4 [CH(SCH 2 COOH) 2 ] 2 ( 1a ) and PhCH(SCH 2 COOH) 2 ( 3 ) in water were found to lead to the decomposition of these ligands with the formation of mercury(II) mercaptoacetate Hg(SCH 2 COOH) 2 ( 2 ) and aldehydes o -C 6 H 4 (CHO) 2 and PhCHO, respectively. A similar reaction was observed between Hg(NO 3 ) 2 and CH 3 (CH 2 ) 2 CH(SCH 2 COOH) 2 ( 4 ). The X-ray structure of Hg(SCH 2 COOH) 2 ( 2 ) shows a linear –S–Hg–S– moiety. The mechanism of the formation of 2 in the reactions between Hg 2+ and thioether carboxylic acids in water is discussed.