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

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.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry (UMKC)

Grantor

University of Missouri--Kansas City

Year dc:date.issued

2014

Author dc:creator

• Darkhalil, Ikhlas Daoud

Advisor dc:contributor.advisor

• Durig, James R.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10355/47477

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/47477