ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Ground-state rotational spectra of the three isotopomers H2CO(centered ellipsis)35ClF, H2CO(centered ellipsis)37ClF and D2CO(centered ellipsis)35ClF of a complex formed by formaldehyde and chlorine monofluoride were observed with a Balle–Flygare, Fourier-transform microwave spectrometer. A fast-mixing nozzle, specially modified to generate a continuous supply of H2CO from paraformaldehyde in situ close to the nozzle exit, was used to preclude the chemical reaction of H2CO and ClF. The rotational constants A0, B0, and C0, centrifugal distortion constants ΔJ, ΔJK, and δJ, components χaa, χbb−χcc, χab of the Cl-nuclear quadrupole tensor, and the spin–rotation coupling constant 1/2(Mbb+Mcc) were determined. Interpretation of the spectroscopic constants led to the conclusion that H2CO(centered ellipsis)ClF is a planar complex of Cs symmetry with r(O(centered ellipsis)Cl)=2.523(7) Å, with an angle 180−φ=69.1(7)° between the C2 axis of H2CO and the O(centered ellipsis)Cl internuclear line, but with a deviation θ of the O(centered ellipsis)Cl–F nuclei from collinearity of only 3.2(7)°. A family relationship between the angular geometries of several complexes B(centered ellipsis)XY, where B is 2,5-dihydrofuran, oxirane, or formaldehyde, and XY is ClF or HCl, is discussed. It is shown that for a given B the angle 180-φ is the same for XY=HCl or ClF, while the nonlinearity θ of the O(centered ellipsis)X–Y system is almost negligible for XY is ClF but significant when XY is HCl. Reasons for this family relationship and the nonlinear O(centered ellipsis)H–Cl hydrogen bonds are discussed. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.475362
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