Accession Number:

ADA164388

Title:

Sequential Excitation Preparation of Molecular Energy Levels with Special Structural and Chemical Properties.

Descriptive Note:

Final rept. 1 Oct 84-30 Sep 85,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY

Personal Author(s):

Report Date:

1986-01-06

Pagination or Media Count:

16.0

Abstract:

Stimulated Emission Pumping Studies of Formaldehyde-Our SEP studies of H2CO are essentially complete. They have yielded an unprecedentedly complete set of anharmonic constants for a 4-atom molecule. SEP studies of D2CO have begun, but the spectra appear much more complex and congested. Quantum Ergodicity in H2CO-The non-rotating levels are well organized and unambiguously assignable as normal mode combination and overtone vibrational states. By J approx. 10, Ka approx. 2 the rotation-vibration levels are intrinsically unassignable, but the spectral density of states is not equal to the total density of states. The spectroscopic distinction between organized and disorganized states is not reflected by any so-far measurable difference in the collisional depopulation rates for organized vs. disorganized levels. Collisional Studies in H2CO-Several new techniques have been demonstrated on H2COH2CO and HxCOHe or Ar rotational energy transfer RET. Transient Gain Spectroscopy TGS and Transient Polarization Spectroscopy TPS have been applied to the H2CO A 1A2 state. RET Follows dipole propensity rules and the rate of elastic reorientation is found to be negligible relative to the total of inelastic rates. Transient Absorption Polarization Spectroscopy TAPS has been applied to highly excited 11,400cm vibrational levels of the H2CO X 1A1 state.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE