Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. IX: Spectra of protiated and partially deuterated cubic magnesium caesium phosphate hexahydrate |
| |
| Institution: | 1. Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, P.O. Box 162, 1001 Skopje, Macedonia;2. Faculty of Natural Sciences and Mathematics, State University of Tetovo, Tetovo, Macedonia;3. Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria;4. Max Planck Institute for Solid State Research, Stuttgart, Germany;5. Macedonian Academy of Sciences and Arts, Skopje, Macedonia;1. Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, PR China;2. Center for Environmental Engineering Design, Chinese Academy of Environmental Sciences, Beijing 100012, PR China;1. UNEP-Tongji Institute of Environment for Sustainable Development, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;2. State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;3. Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;4. Department of Civil and Environmental Engineering, University of California, Berkeley, 629 Davis Hall #1710, Berkeley, CA 94720-1710, USA;1. Upper Assam Advisory Centre, Tea Research Association, Dikom 786101, Assam, India;2. Department of Agricultural Chemistry and Soil Science, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur 741252, Nadia, West Bengal, India;3. Indian Agricultural Statistics Research Institute, New Delhi 110012, India;4. Dibrugarh Polytechnic, Lahowal, Dibrugarh 786010, Assam, India;5. Krupanidhi College of Pharmacy, 12/1, Chikka Bellandur, Carmelaram Post, Bangalore 35, India |
| |
| Abstract: | Infrared and Raman spectra of cubic magnesium caesium phosphate hexahydrate, MgCsPO4·6H2O (cF100), and its partially deuterated analogues were analyzed and compared to the previously studied spectra of the hexagonal analogue, MgCsPO4·6H2O (hP50). The vibrational spectra of the cubic and hexagonal dimorphic analogues are similar, especially in the regions of HOH stretching and bending vibrations. In the difference IR spectrum of the slightly deuterated analogue (<5% D), one distinctive band appears at 2260 cm?1 with a small shoulder at around 2170 cm?1, but only one band is expected in the region of the OD stretchings of isotopically isolated HDO molecules. The small weak band could possibly result from second-order transitions (a combination of HDO bending and some libration of the same species) rather than statistical disorder of the water molecules. By comparing the IR spectra in the region of external vibrations of water molecules of the protiated compound recorded at RT (room temperature) and at LNT (liquid nitrogen temperature) and those in the series of the partially deuterated analogues, it can be stated with certainty that the bands at 924 and 817 cm?1 result from librations of water molecules, rocking and wagging respectively. And the band at 429 cm?1 can be safely attributed to a stretching Mg–Ow mode. In the ν3(PO4) and ν4(PO4) region in the infrared spectra, one band in each is observed, at 995 and 559 cm?1, respectively. In the region of the ν1 modes, in the Raman spectrum of the protiated compound, one very intense band was observed at 930 cm?1 which is only insignificantly shifted to 929 cm?1 in the spectrum of the perdeuterated compound. The band at 379 cm?1 in the Raman spectrum could be assigned to the ν2(PO4) modes. With respect to the phosphate ion vibrations, the comparison between the two polymorphic forms of MgCsPO4·6H2O and their deuterated compounds shows that ν1(PO4) and ν3(PO4) appear at lower wavenumbers in the cubic phase than in the hexagonal phase. These data are in full agreement with the lower repulsion potential at the cubic lattice sites compared with that for the hexagonal lattice sites. |
| |
| Keywords: | Caesium magnesium phosphate hexahydrate Cubic Infrared spectra Raman spectra X-ray powder diffraction |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
