The infrared and Raman spectra (3200 to 50 cm-1) of the gas, liquid or solution, and solid have been recorded of isocyanocyclopentane, c-C5H9NC. FT-microwave studies have also been carried out and 23 transitions were recorded for the envelope-axial (Ax) conformer. Variable temperature (-65 to -100oC) studies of the infrared spectra (3200 to 400 cm-1) dissolved in liquid xenon have been carried out. From these data, both the Ax and envelope-equatorial (Eq) conformers have been identified and their relative stabilities obtained. The enthalpy difference has been determined to be 102 � 10 cm-1 (1.21 � 0.11 kJ mol-1) with the Ax conformer the more stable form. The percentage of the Eq conformer is estimated to be 38 � 1% at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing several different basis sets up to aug-cc-pVTZ from both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been made for the observed bands for both conformers with initial predictions by MP2(full)/6-31G(d) ab initio calculations to obtain harmonic force constants, wavenumbers, infrared intensities, Raman activities and depolarization ratios for both conformers. Structural parameters for the Ax form were determined by using rotational constants obtained from FT-microwave study.

Microwave, structural, conformational, vibrational studies and ab initio calculations of isocyanocyclopentane

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.