Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Poster session, D42 89Internal dynamics in phenylacetateLuca Evangelisti, Assimo Maris, Sonia Melandri, Walther CaminatiDipartimento di Chimica “G. Ciamician”, Università di Bologna, Italy,luca.evangelisti6@unibo.itSimilarly to benzyl alcohol 1 and to tetrahydrofuran 2,3 , phenylacetate is expected to existin four equivalent minima upon the internal rotation around the C1-O7 bond. Inaddition, the internal rotation of the methyl group is expected to have a low V 3 hinderingbarrier. As a result, the rotational transitions are expected to have at least a four-foldstructure. We could assign the rotational spectra of three low energy tunneling states,two of them (A1 and A2) coupled because of the double minimum potential and two ofthem (A1 and E1) coupled because of the methyl group internal rotation. The couplingsof A1 with A2, and of A1 with E1 have been interpreted with coupled Hamiltoniansthrough the use of SPFIT Picket’s suite of programs.In the Figure below, the fourfold potential energy surface originated by the internalrotation described by the C2C1-O7C8 dihedral angle is shown. We observed only thedoubling originated by the low barrier tunnelling (at 90 or 270).Evangelisti L.Maris A.Melandri S.Caminati W.Fig. 1: Potential energy barrier associated to the C2C1-O7C8 dihedral angle.References[1] K.A. Utzat, R.K. Bohn, J.A. Montgomery Jr, H.H. Michels, W. Caminati, J. Phys.Chem. A 114, 6913, 2010.[2] R. Meyer, J. C. López, J. L. Alonso, S. Melandri, P. G. Favero and W. Caminati, J.Chem. Phys., 111: 7871, 1999.[3] D. G. Melnik, S. Gopalakrishnan, T. A. Miller and F. C. De Lucia, J. Chem. Phys.,118: 3589, 2003.