ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The Raman and IR spectra of chloro- and bromo-cyclobutane as vapours, liquids and as amorphous and crystalline solids were recorded at various temperatures. Additional IR spectra of the high-pressure crystalline phases were obtained at ca 25 kbar pressure. IR matrix isolation spectra were recorded at 14 K, using the hot nozzle technique.Evidence is presented to show that chloro- and bromo-cyclobutane have a second (axial) conformer existing in amounts less than 10% for chloro- and 3% for bromo-cyclobutane at ambient temperature, in addition to the dominant (equatorial) conformer. From the study of the Raman spectra of the liquid and vapour as a function of temperature, enthalpy differences between the two conformers were calculated. The axial conformers could not be trapped at 17 K, revealing the barrier to ring conversion to be smaller than 5 kJ mol-1.New vibrational assignments, supported by normal coordinate analyses are presented for both compounds.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250200408
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