Dry and wet mechanochemical synthesis of piroxicam and saccharin co-crystals and evaluation by powder X-ray diffraction, thermal analysis and mid- and near-infrared spectroscopy

Novelp-xylylene-bis(thioacetic) acid (p-XBTA) and its co-crystals with 2-amino-4,6-dimethylpyrimidine (DMP) have been synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy and thermal analysis methods (TG/DSC).

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Characterization of Three 'Active' Rhodium(III) Hydroxides

Australian Journal of Chemistry ◽

10.1071/ch9950557 ◽

1995 ◽

Vol 48 (3) ◽

pp. 557 ◽

Cited By ~ 10

Author(s):

SJ Crimp ◽

L Spiccia

Keyword(s):

Thermal Analysis ◽

Thermal Decomposition ◽

Infrared Spectroscopy ◽

Ion Exchange ◽

Ion Exchange Chromatography ◽

Exchange Chromatography ◽

X Ray Diffraction ◽

X Ray

Pure solutions of [ Rh (H2O)6]3+, dimer [Rh2(μ-OH)2(H2O)8]4+ and trimer [Rh3(μ-OH)4(H2O)10]5+ have been converted into their respective 'active' hydroxides by dropwise addition to an imidazole solution. These 'active' hydroxides have been analysed by a variety of techniques including rhodium determination, infrared spectroscopy, thermal analysis and powder X-ray diffraction. Purity determinations using ion-exchange chromatography showed that the three hydroxides consist primarily of the neutral forms of the starting aqua ion (>96%) with small amounts of species with higher nuclearity. Rhodium analysis and thermogravimetric measurements confirmed the composition of these hydroxides to be Rh (OH)3(H2O)3.H2O, Rh2(μ-OH)2(OH)4(H2O)4 and Rh3(μ-OH)4(OH)5(H2O)5.5H2O. A scheme for the thermal decomposition of each of the hydroxides has been proposed on the basis of the t.g . and d.t.a . data and the knowledge that the final product in each case is α-Rh2O3. Heating of the hydroxides in air resulted in oxidation of RhIII to RhIV (temperature 250-300°C) forming RhO2 which on further heating decomposed to α-Rh2O3 and dioxygen.

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Boron Carbide-Based Ceramics Via Polymer Route Synthesis

MRS Proceedings ◽

10.1557/proc-249-15 ◽

1991 ◽

Vol 249 ◽

Author(s):

Haixing Zheng ◽

Kevin Thorne ◽

J.D. Mackenzie ◽

Xiaoguang Yang ◽

M.F. Hawthome

Keyword(s):

Thermal Analysis ◽

Infrared Spectroscopy ◽

High Temperature ◽

Nmr Spectroscopy ◽

Physical Properties ◽

Boron Carbide ◽

X Ray Diffraction ◽

Polymeric Precursors ◽

X Ray ◽

Crystalline Boron

ABSTRACTBoron carbide is a ceramic material with excellent high temperature physical properties. As compared to conventional techniques, the preparation of boron carbide from polymeric precursors is attractive as this technique offers a number of unique advantages. In this paper, the screening of polymeric precursors to boron carbide will be discussed. Two promising boron carbide, carborane containing polymeric precursors have resulted in 60-70 wt.% ceramic yields. The chemistry of polymer synthesis and the transformations from the polymer to amorphous and crystalline boron carbide were investigated with infrared spectroscopy, NMR spectroscopy, thermal analysis, and x ray diffraction.

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