The Microwave Spectrum of the Mono Deuterated Species

Overview • The normal species • Mono deuterated species PEF • Energy level calculation

The normal species It is a molecule of astrophysical interest which has been the

HCOOCH 3 PEF of the mono deuterated species

Tunneling sublevels 81. 8 MHz 405 MHz HCOOCH 3 ~10 cm-1 HCOOCH 2 D

Spectroscopic parameters Parameters Number Relation h 2, c 2, q 2, f 2 3

Rotational dependence of the tunneling J 0, J J 2, J-2 J 4, J-4

Rotational dependence of the tunneling J 1, J J 3, J-2 J 5, J-4

Rotational dependence of the tunneling High Kc-values, tunneling depends on Kc only

The data Range Uncertainty N Technique 7 to 70 GHz 150 k. Hz 352

Analysis results Data N RMS 7 to 70 GHz 352 0. 232 MHz 150

Spectroscopic parameters D out of plane configurations

q 2 and f 2 calculation Values for q 2 and f 2 can

Tunneling splitting rotational dependence Using the structure of Curl: 1 1. Curl, J. Chem.

Slides: 16

Download presentation

The Microwave Spectrum of the Mono Deuterated Species of Methyl Formate HCOOCH 2 D L. H. Coudert, a L. Margulès, b G. Wlodarczak, b and J. Demaisonb a. LISA, CNRS/Paris 12 University, Créteil, France b. Ph. LAM, CNRS/Lille I University, Villeneuve d’Ascq, France

Overview • The normal species • Mono deuterated species PEF • Energy level calculation • The data • Analysis results

The normal species It is a molecule of astrophysical interest which has been the subject of many investigations. Non-rigid molecule displaying internal rotation of the methyl group. 4270 transitions measured for the A and E-species up to J = 62 and within vt = 0 and 1. The barrier to internal rotation is V 3 = 370 cm-1

HCOOCH 3 PEF of the mono deuterated species

HCOOCH 2 D 10 cm-1

Tunneling sublevels 81. 8 MHz 405 MHz HCOOCH 3 ~10 cm-1 HCOOCH 2 D For J > 0, the rotational dependence of the tunneling splitting must be taken into account. The IAM water dimer 1 formalism will be used. 1. Hougen, J. Mol. Spec. 114, 395 (1985) & Coudert and Hougen, J. Mol. Spec. 130, 86 (1988)

h 2, c 2, q 2, f 2 aeq = 240 aeq = 120 h 0, c 0, q 0, f 0 aeq = 0

Spectroscopic parameters Parameters Number Relation h 2, c 2, q 2, f 2 3 c 2 = f 2 + p h 0, c 0, q 0, f 0 0 not used A, B, C 3 D in plane A, B, C 3 D out of plane 9 zeroth order parameters

Rotational dependence of the tunneling J 0, J J 2, J-2 J 4, J-4 J 6, J-6 J 8, J-8 J 10, J-10 J 12, J-12

Rotational dependence of the tunneling J 1, J J 3, J-2 J 5, J-4 J 7, J-6 J 9, J-8 J 11, J-10 J 13, J-12

Rotational dependence of the tunneling High Kc-values, tunneling depends on Kc only

The data Range Uncertainty N Technique 7 to 70 GHz 150 k. Hz 352 Stark 150 to 650 GHz 30 k. Hz 1126 BWO Max J is 61, max Ka is 42 1042 a-type and 435 b-type with Dv = 0

Analysis results Data N RMS 7 to 70 GHz 352 0. 232 MHz 150 to 650 GHz 1126 0. 189 MHz All 1478 0. 200 MHz Unitless standard deviation is 4. 3

Spectroscopic parameters D out of plane configurations

q 2 and f 2 calculation Values for q 2 and f 2 can be calculated from the geometry of the molecule along the tunneling path. 1 1. Hougen, J. Mol. Spec. 114, 395 (1985) & Coudert and Hougen, J. Mol. Spec. 130, 86 (1988)

Tunneling splitting rotational dependence Using the structure of Curl: 1 1. Curl, J. Chem. Phys. 30, 1529 (1959)