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Room temperature spectroscopic investigations of K 14 NO 3 , K 15 NO 3 , K 14 N 16 O 3− x 18 O x and a 1:1 mixture of K 14 NO 3 and K 15 NO 3 : intermolecular coupling revealed in the vibrational spectra
Author(s) -
Chakraborty Taposh,
Bajpai P. K.,
Verma A. L.
Publication year - 1999
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/(sici)1097-4555(199903)30:3<189::aid-jrs350>3.0.co;2-2
Subject(s) - raman spectroscopy , intermolecular force , chemistry , ion , microcrystalline , rotational–vibrational coupling , infrared , analytical chemistry (journal) , spectral line , isotopic shift , infrared spectroscopy , molecular vibration , dipole , magnetic dipole–dipole interaction , molecular physics , crystallography , molecule , optics , physics , organic chemistry , astronomy , chromatography
The diffuse reflectance Fourier transform IR (DRIFT) andRaman spectra for microcrystalline K 14 NO 3 , K 15 NO 3 , K 14 N 16 O 3− x 18 O x and a 1: 1 mixture of K 14 NO 3 and K 15 NO 3 were measured at room temperature. A newassignment for the observed factor group split components of theasymmetric N–O stretching mode and infrared evidence for theexistence of dynamically disordered NO 3 − ions is proposed. Attractive intermolecular dipolar interaction amongthe NO 3 − ions along the chain is invokedto explain the spectral features around the asymmetric stretchingmode region in the Raman spectrum of the 1: 1 mixed salt of K 14 NO 3 and K 15 NO 3 . Analysis ofthe experimental data for the oxygen‐enriched salt alsodemonstrates the existence of intermolecular coupling in theasymmetric stretching mode region. The intensities of the Ramancomponents of the totally symmetric N–O stretching andin‐plane bending mode regions correlate almost quantitativelywith the calculated distribution of the various isotopes of NO 3 − ions in 18 O‐enriched KNO 3 . The IR intensity of the corresponding bands, on theother hand, is dependent on the symmetry of the respective isotopicspecies. Copyright © 1999 John Wiley & Sons, Ltd.