Phosphorus compounds, infrared

Corbridge 3ss) has given an extensive review of the infrared qiectra of phosphorus compounds. A review exclusively concerned with the vibrational spectra of organophosphorus compounds has also appeared 3 9). Many studies, containing infrared spectra of R-dtp complexes have been reported 112,118,122,123,... 

The emitting species for sulfur compounds is excited S2. The lambda maximum for emission of excited S2 is approximately 394 nm. The emitter for phosphorus compounds in the flame is excited HPO with a lambda maximum equal to doublet 510-526 nm. In order to detect one or the other family of compounds selectively as it elutes from the GC column, the suitable band-pass filter should be placed between the flame and the photomultiplier tube to isolate the appropriate emission band. In addition, a thermal infrared filter is mounted between the flame and the photomultiplier tube to isolate only the visible and UV radiation emitted by the flame. Without this filter, the large amounts of infrared radiation emitted by the combustion reaction of the flame would heat up the photomultiplier tube, thus increasing its background signal. 

Figure 3 Infrared correlation chart for phosphorus compounds ...

Corbridge, D.E.C., The infrared spectra of phosphorus compounds, in Topics in Phosphorus Chemistry, Vol. 6, John Wiley Sons, New York, 1969, pp. 235-366... 

In a systematic study on phosphorus compounds by infrared spectrophotometry, Corbridge (100) has demonstrated that barium salt of... 

Table 4.3m summarises some of the infrared modes produced by phosphorus compounds. 

Figure 4.9 below shows the spectrum of a phosphorus compound with the empirical formula C2H7PO3. Assign the major infrared bands in this spectrum. 

Figure 4.9 Infrared spectmm of an unknown phosphorus compound (C2H7PO3) (cf. SAQ 4.6). Reproduced by permission of J. Emsley and D. Hall, from The Chemistry of Phosphorus, Harper and Row, London, p. 107 (1976).

The first overtone of P-H stretching was found at 5288 cm (1891 nm) in a number of organo-phosphorus compounds. It is slightly more intense than the S-H absorption, having a molar absorptivity of about 0.24 1/mol-cm. It is described as being more diffuse and less sharp, however. The POH group is observed in phosphorothioic acids. The absorption is significantly shifted relative to the hydroxyl in alcohols, as it is in mid-infrared. The near-infrared (NIR) peak appears at about 5241 cm (1908 nm). 

During the late 1950s and early 1960s interest was regenerated into the outcome of the reaction and a number of groups studied this reaction. Ramirez et proposed structure 80 since a five coordinated phosphorus compound was isolated. Structure 81 was proposed by Horner and KlupfeP based on conjugate addition, whereas infrared spectroscopic study. 

R. A. Y. Jones and A. R. Katritzky, Infrared and Nuclear Magnetic Response Spectra of Some Cyclic Phosphorus Compounds, J. Chem. Sw. 1960, 4376-4379. 

Reviews have been published dealing with the infrared spectra of organic phosphorus compounds, " as has a correlation chart for inorganic phosphorus compounds. 

L. C. Thomas, Interpretation of the Infrared Spectra of Organo-phosphorus Compounds. Heyden, London, 1974. 

Chapman, A. C., and L. E. Thirlwell, 1964. Spectra of phosphorus compounds. I. Infrared spectra of orthophosphates. Spectrochim. Acta 20 937. 

Mutschin, A., and K. Maenuchen, 1957. Infrared absorption spectra of different phosphorus compounds. I. Alkali orthophosphates. Z. Anal. Chem. 156 241. 

Pustinger, J. U., Jr., W. T. Cave, and M. L. Nielson, 1959. Infrared spectra of inorganic phosphorus compounds. Spectrochim. Acta 15 909. 

Just as in the case for the hydrosphere, the atmosphere participates in all of the major biogeochemical cycles (except for phosphorus). In turn, the chemical composition of the atmosphere dictates its physical and optical properties, the latter being of great importance for the heat balance of Earth and its climate. Both major constituents (O2, H2O) and minor ones (CO2, sulfur, nitrogen, and other carbon compounds) are involved in mediating the amounts and characteristics of both incoming solar and outgoing infrared radiation. 

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