Frost Ray L, Cejka Jirí, Ayoko Godwin A, Weier Matt
Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Spectrochim Acta A Mol Biomol Spectrosc. 2007 Apr;66(4-5):979-84. doi: 10.1016/j.saa.2006.04.036. Epub 2006 May 19.
Raman spectroscopy at 298 and 77 K of bergenite has been used to characterise this uranyl phosphate mineral. Bands at 995, 971 and 961 cm-1 (298 K) and 1006, 996, 971, 960 and 948 cm-1 (77K) are assigned to the nu1(PO4)3- symmetric stretching vibration. Three bands at 1059, 1107 and 1152 cm-1 (298 K) and 1061, 1114 and 1164 cm-1 (77 K) are attributed to the nu3(PO4)3- antisymmetric stretching vibrations. Two bands at 810 and 798 cm-1 (298 K) and 812 and 800 cm-1 (77 K) are attributed to the nu1 symmetric stretching vibration of the (UO2)2+ units. Bands at 860 cm-1 (298 K) and 866 cm-1 (77 K) are assigned to the nu3 antisymmetric stretching vibrations of the (UO2)2+ units. UO bond lengths in uranyls, calculated using the wavenumbers of the nu1 and nu3(UO2)2+ vibrations with empirical relations by Bartlett and Cooney, are in agreement with the X-ray single crystal structure data. Bands at (444, 432, 408 cm-1) (298 K), and (446, 434, 410 and 393 cm-1) (77 K) are assigned to the split doubly degenerate nu2(PO4)3- in-plane bending vibrations. The band at 547 cm-1 (298 K) and 549 cm-1 (77 K) are attributed to the nu4(PO4)3- out-of-plane bending vibrations. Raman bands at 3607, 3459, 3295 and 2944 cm-1 are attributed to water stretching vibrations and enable the calculation of hydrogen bond distances of >3.2, 2.847, 2.740 and 2.637 A. These bands prove the presence of structurally nonequivalent hydrogen bonded water molecules in the structure of bergenite.
在298K和77K温度下对磷铀矿进行拉曼光谱分析，以表征这种磷酸铀酰矿物。995、971和961cm-1（298K）以及1006、996、971、960和948cm-1（77K）处的谱带归属于（PO4）3-的ν1对称伸缩振动。1059、1107和1152cm-1（298K）以及1061、1114和1164cm-1（77K）处的三个谱带归因于（PO4）3-的ν3反对称伸缩振动。810和798cm-1（298K）以及812和800cm-1（77K）处的两个谱带归因于（UO2）2+单元的ν1对称伸缩振动。860cm-1（298K）和866cm-1（77K）处的谱带归属于（UO2）2+单元的ν3反对称伸缩振动。利用Bartlett和Cooney的经验关系式，通过（UO2）2+的ν1和ν3振动波数计算出的铀酰中的UO键长，与X射线单晶结构数据一致。（444、432、408cm-1）（298K）以及（446、434、410和393cm-1）（77K）处的谱带归属于分裂的双重简并（PO4）3-面内弯曲振动。547cm-1（298K）和549cm-1（77K）处的谱带归因于（PO4）3-面外弯曲振动。3607、3459、3295和2944cm-1处的拉曼谱带归因于水的伸缩振动，并能计算出氢键距离分别为>3.2、2.847、2.740和2.637 Å。这些谱带证明了磷铀矿结构中存在结构不等价的氢键水分子。
