Raman Spectroscopy of Rhombohedral P₄O₁₀

Abstract

A complete Raman vibrational analysis has been performed on phase-pure rhombohedral phosphorus pentoxide (P4O10) at room temperature. The “molecular” T d symmetry is reduced to C 3 v symmetry when bound in the rhombohedral crystalline lattice. Therefore, the 15 fundamental modes of vibration irreducibly represented as Γvib = 3A1 + 3E + 3T1 + 6T2 reduce to 21 fundamental modes with a factor group analysis resulting in Γvib = 9A1 + 12E for the irreducible representation, all of which are Raman active. Complete vibrational assignments and relative intensities, including all T2 to E and A1 splittings, are reported. Five new E fundamentals (262, 329, 419, 829, and 846 cm-1) in the C 3 v symmetry were observed. All peaks show good agreement with theoretical calculations.

Black Phosphorus: Degradation Favors Lubrication

“…According to the reported Raman frequencies (per centimeter) that are related to various phosphorus-containing functional groups − (listed in Table S1), it can be concluded that the peaks in the 800–900 cm –1 range are mainly assigned to the Raman active modes of phosphorus oxides, while those in the 900–1100 cm –1 range correspond to the phosphorus oxyacid species. When exposed in ambient conditions for 2 and 16 h, the surfaces of BP flakes are mainly composed of P=O and P–O–P bonds owing to the oxidized phosphorus as well as possible P­(OH) 3 groups, considering water absorption. ,− As the increasing peak located in the 900–1100 cm –1 range shows in Figure b, massive phosphorus oxyacid containing orthophosphate group formed as a result of the water-accelerated oxidation and the dissolution of the phosphorus oxides after 40 h of exposure, corresponding to the formation of large droplets on the BP flake surface. The weak P–O stretching vibration of the HPO 3 2– group at around 920 cm –1 is also observed in the BP sample at the early oxidation stage (e.g., 2 h and 16 h), indicating the formation of phosphorus III.…”

Efficient conversion of arylene precursors into photoluminescent phosphonates for surface modification of metal oxides

“…Although the successful grafting of 1e on ZrO 2 was unambiguously verified by 31 P MAS NMR spectroscopy as illustrated above, there is no P-O absorption peak in the corresponding IR spectrum. This might be due to the quantitative conversion of the P-O-alkyl bonds into the much more far-IR shifted P-O-metal bonds, 35 which is also supported by the comparison of the 31 P CP MAS NMR spectra given in Fig. 2.…”