The correlation between carbon tetrachloride Raman spectra and methanol configuration in CH 3 OH/CCl 4 mixtures Kamal Kayed Higher institute for Laser Research and applications (HILRA), Damascus University, Syria. Abstract: In this study, we investigate the possibility of using the numerical data from the mathematical processing of Raman spectra of carbon tetrachloride to obtain a graphical curve that summarizes the structural changes of methanol resulting from changes in concentration for CH 3 OH/CCl 4 mixtures. To find this empirical model, we supposed that there are two factors affecting intensity. The first factor is the decrease of carbon tetrachloride concentration due to dilution with methanol, and the other is the degree of order of the C-Cl polarized bonds distributed around the methanol clusters. The obtained results indicate that the changes of intensity resulting from the second factor are in accordance with the changes of the methanol structure in the solution. The results show also, that the relationship between the shape factor and the intensity changes related to the degree of order of C-Cl polarized bonds depend on both the pattern of vibration of the bond and the structure of methanol clusters in the solution. Keywords: Raman; carbon tetrachloride; methanol; Shape factor. 1. Introduction The effect of the sample interaction with the solvent appears clearly in the Raman spectra where the interactions lead to concentration-dependent alteration of the intensity, so that the linearity of the relationship between concentration and intensity no longer exists [1]. Stronger interactions between the sample and the solvent may also cause shifting of the bond maxima of the dissolved sample by a few wavenumbers [2]. The effect of the sample interaction with the solvent appears clearly in the Raman spectra where the interactions lead to concentration-dependent alteration of the intensity, so that the linearity of the relationship between concentration and intensity no longer exists [1]. Stronger interactions between the sample and the solvent may also cause shifting of the bond maxima of the dissolved sample by a few wavenumbers [2]. In Raman spectroscopy, the obtained shape of the spectral line results from the accumulation of individual scattered molecules, and is heavily influenced by the environment. All molecules vibrate together in a consistent manner, but movement and the slight differences in the vibrational frequency makes it random with time [1]. The identification of the main features of the measured spectrum, and so the accuracy of characterization process depends largely on the convenience of the used peak fitting process. In liquids, the line shape has features of both Gaussian and Lorentzian character [1]. The simplest model for this involves the combination Gaussian-Lorentzian (G-L) profile, represented as a*G + (1-a)*L with a (shape factor) being the fraction of Gaussian character (0 ≤ a ≤ 1). The increased in the a factor value demonstrates the increased International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN: 0974-4290 Vol.8, No.10 pp 187-193, 2015