Raman, Infrared and Microwave Spectra, Conformational Stability, R₀ Structural Parameters and Vibrational Assignments of Some Organoamines, Organophosphines, Alcohols And Substituted Four And Five Membered Rings
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Abstract
The infrared and Raman spectra of compounds with amino, phosphours, silane and hydroxyl functional groups, as well as some with cyclic skeletal structures have been recorded of the gas and in condensed phases. Temperature dependent infrared and Raman spectra in xenon solutions were also recorded. A complete vibrational assignment, conformational stability determination and adjusted r0 parameters have been obtained for each of the most stable conformers and in some cases for the less stable conformers. The vibrational assignments were supported by normal coordinate calculations with scaled force constant from MP2(full)/6-31G(d) calcualtions from which the fundamental vibrational frequencies, infrared intensities, Raman activities, depolarization ratios and infrared band contours were predicted. For ethylamine the enthalpy difference has been determined to be 62 ± 6 cm-1 (0.746 ± 0.072 kJ mol⁻¹) with the trans conformer the more stable form. For isorpropylamine, the enthalpy difference of the sample dissolved in Raman xenon has been determined to be 113 ± 11 cm⁻¹ (1.35 ± 0.13 kJ mol⁻¹) with the trans conformer the more stable form. For n-propylamine, the five possible conformers have been identified and their relative stabilities obtained with enthalpy difference relative to Tt for Tg of 79 ± 9 cm⁻¹ (0.9 ± 0.1 kJ/mol); for Gg of 91 ± 26 cm⁻¹ (1.08 ± 0.3 kJ/mol); for Gg' of 135 ± 21 cm⁻¹ (1.61 ± 0.2 kJ/mol); for Gt of 143 ± 11 cm⁻¹ (1.71 ± 0.1 kJ/mol). For 2-cyanoethylamine, the enthalpy differences between the Gg and Gt conformers was determined to be 75 cm⁻¹ and for the Gg to Tg form 333 cm⁻¹. For 2,2difluoroethylamine, the enthalpy differences have been determined among the most stable Tt conformer and the second stable conformer, Gg, to be 83 ± 8 cm⁻¹ (0.99 ± 0.10 kJ/mol), the third stable conformer, Gt, to be 235 ± 11 cm⁻¹ (2.81 ± 0.13 kJ/mol). For 2,2,2 trifluoroethylamine, the enthalpy difference has been determined to be 267 ± 27 cm⁻¹ (3.19 ± 0.32 kJ mol⁻¹) with the trans conformer the more stable form. For 2,2,3,3,3-pentafluoropropylamine, the enthalpy difference has been determined between the more stable Tt conformer and the less stable Tg form to be 280 ± 14 cm⁻¹ (3.35 ± 0.17 kJ/mol). In case of cyclopentylamine, the four possible conformers have been identified and their relative stabilities obtained with enthalpy difference relative to t-Ax of 211 ± 21 cm⁻¹ for t-Eq ≥ 227 ± 22 cm⁻¹ for g-Eq ≥ 255 ± 25 cm⁻1 for g-Ax. For cyclohexylamine, the four possible conformers have been identified as t-eq> g-eq>t-ax>g-ax. Microwave spectra for several of the molecules have been investigaged from 10,000 to 21000 MHz with transtions for the most stable conformer and in some cases for the less stable conformers. By utilizing the rotational constants reported from microwave studies combined with the structural parameters predicted from the MP2(full)/6-311+G(d,p) calcualtions, adjusted r0 strutral paramerters have been obtained for the most stable conformer(s) of the different molecules studied.
Table of Contents
Introduction -- Experimental and theoretical methods -- Microwave spectra and conformational studies of etyhl-amine from temperature dependent raman spectra of xenon solutions and ab initio calculations -- Conformational and structural studies of isopropyl-amine from temperature dependent raman spectra of xenon solutions ad ab initio calculations -- Conformational and structural studies of N-ropylamone propylamine from temperature dependent raman and far infrared spectra of xenon solutions and ab initio calculations -- Infrared and raman spectrs, r0 structural parameters, conformational stability, and vibrational assignment of 2-cyanoethylamine -- Conformational and structural studies of 2,2-difluoro-ethylamine from temperature dependent infrared spectra of xenon solution and ab initio calculations -- Conformational and structural studies of 2,2,2 trifluoroethylamine from temperature dependent raman spectra of xenon solutions and ab initio calculations -- Conformational, vibrational, and structural studies of 2,2,3,3,3-pentafluropropylamine from raman and infrared spectra of gas, liquid, xenon solutions -- Conformational stability, R0 structural parameters, vibrational assignments and ab initio calculations of ethyldichlorophosphine -- R0 structural parameters, conformational stability, barriers to internal rotation, and vibrational assignments for trans and gauche ethanol -- Conformational and structural studies of ethynyl-cyclopentane form temperature dependent raman spectra of xenon solutions and ab initio calculations -- Microwave, structural, conformational, vibrational studies and ab initio calculations of isocyanocyclopentane -- Microwave, infrared, and raman spectra, structural parameters, vibrational assignments and theoretical calculations of dislacyclopentane -- Microwave, infrared, and raman spectra, structural parameters, vibrational assignments and theoretical calculations of 1,1,3,3-tetrafluoro-1,3-disilacyclopentane -- Raman and infrared, microwave spectra adjusted R0 structural parameters, conformational stability and vibrational assignments of cyclopentylamine -- Microwave, infrared, and raman spectra adjusted R0 structural parameters conformational stabilities vibrational assignments and theoretical calculations of cyclobutylcarboxylic acid chloride -- Vibrational assignments theoretical calculations structural parameters and conformer stability determinations of cyclobutyldichlorosilane
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Ph.D.