T. Sakaizumi et al., MICROWAVE-SPECTRUM AND MOLECULAR-STRUCTURE OF (Z)-CHLOROACETALDEHYDE OXIME, Journal of molecular spectroscopy, 179(2), 1996, pp. 324-333
Citations number
15
Categorie Soggetti
Spectroscopy,"Physics, Atomic, Molecular & Chemical
The microwave spectra of (Z)-(ClCH2CH)-Cl-35=NOH, (Z)-(ClCH2CH)-Cl-37=
NOH, (Z)-(ClCH2CH)-Cl-35=NOD, and (Z)(ClCH2CH)-Cl-37=NOD have been obs
erved in the frequency range from 16.5 to 40.0 GHz. The rotational and
centrifugal distortion constants of four isotopic species and the nuc
lear quadrupole coupling constants of the Cl-35 species were determine
d. The values of planar moment (P-alpha = (I-a + I-b - I-c)/2) Obtaine
d for four isotopic species were found to be 1.761(14), 1.800(18), 1.7
77(19), and 1.770(18) u Angstrom(2) in the ground vibrational state. T
he unchanged values of P-cc shaw that the chlorine and hydroxyl hydrog
en atoms lie in or are very close to the ab inertial plane of the mole
cule. The conformation of the Z-ferm was determined to be Calcd I (phi
(1) = 180 degrees, phi(2) = 180 degrees), as shown in Fig. 1, from the
comparison of the observed and calculated rotational constants and co
ordinates of the chlorine and hydroxyl hydrogen atoms. The determined
conformation is consistent with that reported by an electron diffracti
on study (K. Iijima, T. Hanamori, T. Sakaizumi, and O. Ohashi, J. Mol.
Struct. 299, 149-153 (1993).). One excited vibrational state is assig
ned to the C-C torsional mode, and it is anharmonic. This fact is also
consistent with the result of a large amplitude motion about the C-C
single bond reported by a gas-phase electron diffraction study. Assumi
ng the skeleton of the heavy atoms is a planar molecule, the seven str
uctural parameters of the Z-form (anti-form) were fitted to the eight
rotational constants (B and C) of four isotopic species. The obtained
structural parameters (r(0)) are almost the same as those obtained by
electron diffraction study (r(alpha)) within the errors. (C) 1996 Acad
emic Press, Inc.