Title 



Raman and infrared, microwave spectra, conformational stability, adjusted r(0) structural parameters, and vibrational assignments of cyclopentylamine
 
Author 



 
Abstract 



Fourier transform microwave spectrum of cyclopentylamine, cC5H9NH2 has been recorded, and seven transitions have been assigned for the most abundant conformer, and the rotational constants have been determined: A = 4909.46(5), B = 3599.01(4), and C = 2932.94(4). From the determined microwave rotational constants and ab initio MP2(full)/6311 + G(d,p) predicted structural values, adjusted r(0) parameters are reported with distances (angstrom): rC(alpha)Cbeta = 1.529(3), rC(beta)Cgamma = 1.544(3), rC(gamma)Cgamma = 1.550(3), rC(alpha)N = 1.470(3), and angles (degrees) angle CCN = 108.7(5), angle C beta C alpha C beta = 101.4(5), and tau C beta C alpha C beta ' C gamma ' = 42.0(5). The infrared spectra (4000220 cm(1)) of the gas have been recorded. Additionally, the variable temperature (60 to 100 degrees C) Raman spectra of the sample dissolved in liquefied xenon was recorded from (380050 cm(1)). The four possible conformers have been identified, and their relative stabilities obtained with enthalpy difference relative to tAx of 211 +/ 21 cm(1) for tEq >= 227 +/ 22 cm(1) for gEq >= 255 +/ 25 cm(1) for gAx. The percentage of the four conformers is estimated to be 53% for the tAx, 11 +/ 1% for tEq, 20 +/ 2% for gAx and 16 +/ 2% for gEq at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing several different basis sets up to augccpVTZ from both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been provided for the observed bands for all four conformers, which are predicted by MP2(full)/631G(d) ab initio calculations to predict harmonic force constants, wavenumbers, infrared intensities, Raman activities, and depolarization ratios for all of the conformers. The results are discussed and compared to the corresponding properties of some related molecules. Copyright (c) 2014 John Wiley & Sons, Ltd.   
Language 



English
 
Source (journal) 



Journal of Raman spectroscopy.  Dordrecht  
Publication 



Dordrecht : 2014
 
ISSN 



03770486
 
Volume/pages 



45:5(2014), p. 392406
 
ISI 



000335515000009
 
Full text (Publisher's DOI) 


  
Full text (publisher's version  intranet only) 


  
