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

90 Poster session, D43High Resolution Infrared Studies of the ν 10 , ν 11 , ν 14 , and ν 18 Levels of[1.1.1]propellaneRobynne Kirkpatrick 1 , Tony Masiello 2 , Matthew Martin 1 , Joseph W. Nibler 1 ,Arthur Maki 3 , Alfons Weber 4 , Thomas A. Blake 51 Oregon State University, U.S.A., joseph.nibler@orst.edu; 2 California State University,East Bay, U.S.A., tony.masiello@csueastbay.edu; 3 15012 24 th Ave., Mill Creek, WAU.S.A., amaki1@compuserve.com; 4 National Institute of Standards and Technology,U.S.A., aweber@nist.gov; 5 Pacific Northwest National Laboratory, U.S.A.,ta.blake@pnl.govKirkpatrick R.Masiello T.Martin M.Nibler J.W.Maki A.Weber A.Blake T.A.The high resolution infrared spectrum of [1.1.1]propellane has been obtained and its kand l structure has been resolved for the first time. In this paper we present results froman analysis of more than 16,000 transitions involving three fundamental bands ν 10(e′),ν 11(e′), ν 14(a 2″) and two difference bands ν 10(e′)-ν 18(e″) and ν 18(e′)-ν 11(e″). Additionalinformation about ν 18 was obtained from the difference band ν 18 +ν 15 - ν 18 and thecombination band ν 18+ν 15. Using fixed ground state constants reported in an earlierpaper 1 , rovibrational constants have been determined for all the vibrational levelsinvolved in these bands. The rovibrational parameters for the ν 18(e″) state were obtainedfrom combination-differences and showed no need to include interactions with otherstates. The ν 10(e′) state analysis was also straight-forward, with a weak Coriolisinteraction with the ν 14(a 2″) levels. The latter levels are much more strongly affected bya strong Coriolis interaction with the nearby ν 11(e′) levels and also by a small butsignificant interaction with a ν 16 (e″) state that is not directly observed. Gaussiancalculations (B3LYP/cc-pVTZ) computed at the anharmonic level aided the analyses byproviding initial values for many of the parameters. These theoretical results generallycompare favorably with the final parameter values deduced from the spectral analyses.Finally, evidence was obtained for several level crossings between the ν 11 and ν 14 levelsand, using a weak coupling term corresponding to a Δk = 5, Δl = -1 matrix element, it waspossible to deduce rotational level spacings in the ground state that give a value of C 0 =0.193658(10) cm -1 . This result, combined with the value of B 0 = 0.28755833(14) cm -1reported earlier 1 , yields an R 0 value of 1.58635(8) Ǻ for the length of the novel axial CCbond in propellane.References[1] R. Kirkpatrick, T. Masiello, N. Jariyasopit, A. Weber, A. Maki, T.A. Blake, andT. Hubler, J. Molec. Spectrosc. 248, 153-160 (2008).