8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P2.59The noncoincidence effect of the overtone of the C=Ostretching mode of acetoneMaurizio Musso, 1 Paolo Sereni, 1 Maria Grazia Giorgini, 2 and Hajime Torii 31 Fachbereich Materialforschung und Physik, Universität Salzburg, Hellbrunnerstrasse 34,5020, Salzburg, Austria2 Dipartimento di Chimica Fisica ed Inorganica, Universitá di Bologna, Bologna,Italy3 Department of Chemistry, School of Education, Shizuoka University, Shizuoka,JapanThe frequency separation between the first moments of the anisotropic and isotropic componentsof the Raman band associated with a vibrational mode having large electric dipolemoment derivatives, i. e. the so-called Raman spectroscopic noncoincidence effect (NCE), isan experimentally accessible observable which reveals the occurrence of resonant intermolecularcouplings between equivalent vibrations in neighbouring molecules within a molecularliquid, see [1] and references therein. In former publications we have extensively reportedexperimental and computer simulation results on the noncoincidence effect of the 12 C=Ostretching vibrational mode ( n 3 ) of acetone as function of dilution in chemical and in isotopicmixtures [2-3]. In the present work we deal with the noncoincidence effect of the overtone 2n 3 of the 12 C=O stretching vibrational mode n 3 of acetone, i. e. NCE(2 n 3 ), showing afrequency separation between the first moments of the anisotropic and isotropic overtone peaksof comparable magnitude as NCE( n 3 ), but opposite in sign, stemming from the isotropic 2 n3 peak at around 3413.9 ± 1 cm and from the anisotropic 2 n 3 peak at around 3407.5 ± 1 cm[3]. The present status of the experimental and simulation studies on NCE(2 n 3 ) will be presented.[1] Torii H. , ”Computational methods for analyzing the intermolecular resonant vibrationalinteractions in liquids and the noncoincidence effect of vibrational spectra”, in Novel Approachesto the Structure and Dynamics of Liquids: Experiments, Theories and Simulations, Samios J. andDurov V. A. (Eds. ), Kluver, pp. 343-360 (2004).[2] Musso M. , Giorgini M. G. , Torii H. , Dorka R. , Schiel D. , Asenbaum A. , Keutel D. , OehmeK. L. , J. Molec. Liquids 125, 115 (2006).[3] Musso M. , Giorgini M. G. , Torii H. , J. Molec. Liquids 147, 37 (2009).59