The Vibrational Spectra of α-alkaline Earth Pyrophosphates

Authors

Bahne C. Cornilsen, Michigan Technological UniversityFollow
R. A. Condrate, Alfred University

Document Type

Article

Publication Date

1-30-1978

Department

Department of Chemistry; Department of Chemical Engineering

Abstract

Raman spectra and middle infrared absorption spectra (4000-200 cm^-1) were measured for α-Ca₂P₂O₇, α-Sr₂P₂O₇, and α-Ba₂P₂O₇. These spectra were interpreted using factor group analyses, and band assignments were made. Noncoincidences in the infrared and Raman spectra of α-Sr₂P₂O₇ indicated that this material possesses the centrosymmetric space group D¹⁶_2h-Pnma rather than the noncentrosymmetric space group, C⁹_2ν-Pna2₁. The similarities between the vibrational spectra of α-Ba₂P₂O₇ and α-Sr₂P₂O₇ suggested that α-Ba₂P₂O₇ is isostructural with α-Sr₂P₂O₇. Differences were noted in the vibrational spectra of monoclinic α-Ca₂P₂O₇ and the two orthorhombic α-phases, α-Sr₂P₂O₇ and α-Ba₂P₂O₇, which were related to differences in their crystal structures. The P₂O₇^4--anions of all three compounds contained nonlinear P O P bond angles.

Publisher's Statement

© 1978

Publication Title

Journal of Solid State Chemistry

Recommended Citation

Cornilsen, B. C., & Condrate, R. (1978). The Vibrational Spectra of α-alkaline Earth Pyrophosphates. Journal of Solid State Chemistry, 23(3-4), 375-382. http://doi.org/10.1016/0022-4596(78)90087-7
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/5365