RATE AND MECHANISM OF INTRAMOLECULAR VIBRATIONAL REDISTRIBUTION IN THE NU(16) ASYMMETRIC METHYL STRETCH BAND OF 1-BUTYNE

被引:58
作者
BETHARDY, GA
PERRY, DS
机构
[1] Department of Chemistry, University of Akron, Akron
关键词
D O I
10.1063/1.464783
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The spectrum of the nu16 asymmetric methyl stretch vibration of 1-butyne near 2991 cm-1 has been studied via direct absorption infrared spectroscopy at a resolution of 35 MHz. Analysis by ground state combination difference indicates that the nu16 band is extensively perturbed by dark vibrational bath states. All of the transitions appear as multiplets of about five eigenstates in a window of about 0.0 1 7 cm-1. A detailed analysis is presented for the upper state levels K(a)' = 0-2 and J' = 0-6. A lack of J' dependence implies anharmonic coupling is dominant and that b- and c-type Coriolis interactions are not important at these low J' values. However, the average dilution factor goes from 0.72 at the K(a)' = 0 to 0.46 at the K(a)' = 2 suggesting weak a-type Coriolis interactions. For the K(a)' = 0 levels, the measured average level density of 17 states/cm-1/symmetry species is comparable to the value of 14 vibrational states/cm-1/symmetry species obtained from a symmetry specific direct count. This is an indication that the dynamics explore all of the energetically available vibrational phase space. The nearly Gaussian distribution of matrix elements suggests that there is significant coupling among the bath states. At the K(a)' = 0 level, the rms anharmonic coupling matrix element is [v(sj)2]1/2 = 0.0125 cm-1. From the frequency-resolved data, a coherently prepared asymmetric methyl stretch in 1-butyne is deduced to decay with a 276 ps time constant to the asymptotic probability of 0.6.
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页码:6651 / 6664
页数:14
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共 91 条
  • [1] FLUORESCENCE AND STIMULATED-EMISSION S1-]SO SPECTRA OF ACETYLENE - REGULAR AND ERGODIC REGIONS
    ABRAMSON, E
    FIELD, RW
    IMRE, D
    INNES, KK
    KINSEY, JL
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1985, 83 (02) : 453 - 465
  • [2] STIMULATED-EMISSION PUMPING OF ACETYLENE - EVIDENCE FOR QUANTUM CHAOTIC BEHAVIOR NEAR 27900 CM-1 OF EXCITATION
    ABRAMSON, E
    FIELD, RW
    IMRE, D
    INNES, KK
    KINSEY, JL
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1984, 80 (06) : 2298 - 2300
  • [3] OPTICAL SELECTION STUDIES OF ELECTRONIC RELAXATION FROM THE S-1 STATE OF JET-COOLED ANTHRACENE-DERIVATIVES
    AMIRAV, A
    HORWITZ, C
    JORTNER, J
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1988, 88 (05) : 3092 - 3110
  • [4] ABSORPTION-SPECTROSCOPY OF ULTRACOLD LARGE MOLECULES IN PLANAR SUPERSONIC EXPANSIONS
    AMIRAV, A
    EVEN, U
    JORTNER, J
    [J]. CHEMICAL PHYSICS LETTERS, 1981, 83 (01) : 1 - 4
  • [5] ANALYSIS OF THE NU-4 AND NU-1 BANDS OF CF3CL MEASURED BY SUPERSONIC FREE-JET FTIR SPECTROSCOPY
    AMREIN, A
    HOLLENSTEIN, H
    LOCHER, P
    QUACK, M
    SCHMITT, U
    BURGER, H
    [J]. CHEMICAL PHYSICS LETTERS, 1987, 139 (01) : 82 - 88
  • [6] HIGH-RESOLUTION INTERFEROMETRIC FOURIER-TRANSFORM INFRARED-ABSORPTION SPECTROSCOPY IN SUPERSONIC FREE JET EXPANSIONS - CARBON-MONOXIDE, NITRIC-OXIDE, METHANE, ETHYNE, PROPYNE, AND TRIFLUOROMETHANE
    AMREIN, A
    QUACK, M
    SCHMITT, U
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1988, 92 (19) : 5455 - 5466
  • [7] [Anonymous], 1972, UNIMOLECULAR REACTIO
  • [8] STRUCTURE AND DYNAMICS OF THE EXCITED CH-CHROMOPHORE IN (CF3)3CH
    BAGGOTT, JE
    CHUANG, MC
    ZARE, RN
    DUBAL, HR
    QUACK, M
    [J]. JOURNAL OF CHEMICAL PHYSICS, 1985, 82 (03) : 1186 - 1194
  • [9] DETERMINATION OF A HIGH BARRIER HINDERING INTERNAL-ROTATION FROM THE GROUND-STATE SPECTRUM - THE METHYLBARRIER OF 1-BUTYNE
    BESTMANN, G
    DREIZLER, H
    [J]. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, 1985, 40 (03): : 263 - 266
  • [10] INFRARED-SPECTRA OF THE NU-2 AND NU-16 BANDS IN THE METHYL STRETCH REGION OF JET-COOLED 1-BUTYNE
    BETHARDY, GA
    PERRY, DS
    [J]. JOURNAL OF MOLECULAR SPECTROSCOPY, 1990, 144 (02) : 304 - 309