AbstractA series of proton acceptor molecules have been studied in order to determine their mode of interaction with the proton donor molecule hydrogen chloride as indicated by the shift in the stretching vibration.
Matrix isolation methods were investigated by pulsed (PMI) and slow-spray-on (SSO) for samples of hydrogen chloride and propenenitrile (acrylonitrile or vinyl cyanide). A high temperature injection system was constructed for molecules of low volatility.
During the initial work at U.C. Swansea the hydrogen chloride was allowed to interact with a series of oxygen containing compounds leading to the detection of molecular complexes.
Subsequently at the Polytechnic of Wales interactions were studied with compounds of the type:
CH2=GH-(CH2 ) n-X n = 0,1,2
CH3 -CH2 -X X = CH3 , Cl, Br,C=N
C1 - (CH2)n -C=N
Weak Van der Waals interactions were measured for CH-^-C^-CHo. Moderate strength hydrogen bonded complexes associated with o and IT electrons were measured in other cases.
Correlations for bifunctional molecules suggested that o bonded forms were preferred to TT bonded forms. In corresponding mixtures of monofunctional compounds o and IT complexes were simultaneously formed.
Gas phase studies were performed but only the complexes due to the nitrile compounds were detected. Calculations were performed so that observed and experimental rotational spacings of vibrational bands could be compared. The calculations being based on assumed geometries for the complexes.
FTIR spectroscopy was used to investigate the enhanced intensity of rotation-vibration bands associated with the low rotational levels of HC1.
|Date of Award||Nov 1984|