Nuclear spin circular dichroism.
Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.
NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland.
Juha
J
Vaara
Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy.
Antonio
A
Rizzo
Department of Physics, Chemistry and Biology, Linköping University, S-58183 Linköping, Sweden.
Joanna
J
Kauczor
Department of Physics, Chemistry and Biology, Linköping University, S-58183 Linköping, Sweden.
Patrick
P
Norman
Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy.
Sonia
S
Coriani
D001554:Benzene / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry; D060526:Magnetic Fields; D009904:Optical Rotation; D011789:Quantum Theory
D016227:Benzoquinones; D005030:Ethylenes; D000431:Ethanol; C004532:quinone; C036216:ethylene; D001554:Benzene