Bond Length and Bond Valence Relationships for Chromium Oxides, Chromium Sulfides, Molybdenum Oxides, and Molybdenum Sulfides

Authors

J. Labrecque, Arkansas Tech University
F. D. Hardcastle, Arkansas Tech UniversityFollow

Abstract

Pauling determined an empirical logarithmic dependence of bond order (bond valence), s, to bond length, R, s = exp(R₀ – R/ b), where R₀ is unit bond length and b is a fitting parameter. Recently, an expression was derived for relating the b fitting parameter to theoretically derived atomic orbital exponents. With a method to calculate b, both R₀ and atomic orbital exponents can be experimentally determined through optimized fitting for Cr-O, Cr-S, Mo-O, and Mo-S. In the present study, bond length – valence relationships are found for Cr-O, Cr-S, Mo-O, and Mo-S chemical bonds using published crystallographic data. In addition, atomic orbital exponents were found for chromium and molybdenum: z­­_Cr = 1.247 and z_Mo = 1.381. Finally, bond lengths of unit bond valence, or true single bonds, were found using the bond valence model: R_o(Cr-O) = 1.770 Å, R_o(Cr-S) = 2.159 Å, R_o(Mo-O) = 1.893 Å, and R_o(Mo-S) = 2.264 Å.

Recommended Citation

Labrecque, J. and Hardcastle, F. D. (2017) "Bond Length and Bond Valence Relationships for Chromium Oxides, Chromium Sulfides, Molybdenum Oxides, and Molybdenum Sulfides," Journal of the Arkansas Academy of Science: Vol. 71, Article 14.
https://doi.org/10.54119/jaas.2017.7119
Available at: https://scholarworks.uark.edu/jaas/vol71/iss1/14