Kripal, Ram and Mishra, Indrajeet and Gupta, S. K. and Arora, Manju (2009) EPR and optical absorption studies on VO2+ ions in l-asparagine monohydrate single crystals. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 71 (5). pp. 1969-1972. ISSN 1386-1425

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Abstract

X-Band electron paramagnetic resonance (EPR) studies of VO2+ ions in l-asparagine monohydrate single crystals have been done at room temperature. Detailed EPR analysis indicates the presence of two magnetically inequivalent VO2+ sites. Both the vanadyl complexes are found to take up interstitial position. The angular variation of the EPR spectra in three planes ab, bc and ca are used to determine principal g and A tensors. For the two sites the spin Hamiltonian parameters are, site I: gx = 1.9633, gy = 2.0274, gz = 1.9797, Ax = 88, Ay = 61, Az = 161 × 10−4 cm−1; site II: gx = 1.9627, gy = 1.9880, gz = 1.9425, Ax = 90, Ay = 66, Az = 167 × 10−4 cm−1. The optical absorption study is also carried out at room temperature and absorption bands are assigned to various transitions. The theoretical band positions are obtained using energy expressions and a good agreement is found with the experimental values. By correlating EPR and optical data different molecular orbital coefficients are evaluated and the nature of bonding in the crystal is discussed.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier B.V.
Uncontrolled Keywords:	Spin Hamiltonian; Optical absorption; Angular variation; Crystal field; Bonding parameters
Subjects:	Biochemistry & Molecular Biology Chemistry Pharmacology & Pharmacy Physics Spectroscopy
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	28 Aug 2012 07:59
Last Modified:	28 Aug 2012 07:59
URI:	http://npl.csircentral.net/id/eprint/495

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