Intermolecular Hydrogen Bonding and Vibrational Analysis of N,N-Dimethylformamide Hexamer Cluster

Bulletin of the Korean chemical society

Yunsoo Kim¹  Choongkeun Lee¹  Kyung Chul Min¹  Soon Kang Hong¹  Sun Kyung Park¹  Nam Soo Lee¹ 

关键词: N;    N-dimethylformamide;    Hexamer cluster;    Vibrational analysis;    Intermolecular hydrogen bonding;    Intermolecular vibrational coupling;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Hexamer cluster of N,N-dimethylformamide(DMF) based on the crystal structure was investigated for the equilibrium structure, the stabilization energies, and the vibrational properties in the density functional force field. The geometry (point group C_i) of fully optimized hexamer clustered DMF shows quite close similarity to the crystal structure weakly intermolecular hydrogen bonded each other. Stretching force constants for intermolecular hydrogen bonded methyl and formyl hydrogen atoms with nearby oxygen atom, methyl C?H···O and formyl C?H···O, were obtained in 0.055 ~ 0.11 and ~ 0.081 mdyn/A, respectively. In-plane bending force constants for hydrogen bonded methyl hydrogen atoms were in 0.25 ~ 0.33, and for formyl hydrogen ~ 0.55 mdynA. Torsion force constants through hydrogen bonding for methyl hydrogen atoms were in 0.038 ~ 0.089, and for formyl hydrogen atom ~ 0.095 mdynA. Calculated Raman and infrared spectral features of single and hexamer cluster represent well the experimental spectra of DMF obtained in the liquid state. Noncoincidence between IR and Raman frequency positions of stretching C=O, formyl C?H and other several modes was interpreted in terms of the intermolecular vibrational coupling in the condensed phase.

【 授权许可】

Unknown