The Structural And Spectral Studies Of Paracetamol And Chitosan

Paracetamol is a popular analgesic and antipyretic medication, and also one of the most important medications which has the largest sales in the world. So it is very important to study the physical and chemical properties of Paracetamol, including its Infaraed spectra and the Raman spectra.Chitosan is a kind of macromoleculelar compound which has a widespread application in biological medicine, chemical engineering, health and other important fields. As a sugar, the study of chitosan's molecular structure is of extremely important significance. The method of studying its decomposition fragments structure of chitosan may be a way to further study because of its big molecular weight. DFT (Density Functional Methods) is one of the electronic structure theories developed in recent years, which is well used in theory studying of the physics and chemical properties of molecular.In this thesis, the method of density functional theory is used to study the Raman spectra and infrared spectra of Paracetamol. It can be seen that the Raman spectrum of the calculation results and the experimental results of the Paracetamol molecular are well in accordance with each other by comparison. The complicated vibration modes were explained in the way of refering the theoretical result and other papers. At the same time, the fundamental structures of chitosan molecular was also geometry optimized with DFT and Monte Carlo Methods in this thesis. These works were done for the future research of the NMR, Raman Spectra and Infrared Spectra of chitosan molecular.There are four chapters in this thesis: In chapter 1, the basic information of chitosan and APAP, DFT, Gaussian03, Monte Carlo Method and some basis used in this thesis were introduced.In chapter 2,the density functional theory (DFT) calculation and experimental results of Raman spectrum and IR spectrum of paracetamol were obtained, and the assignments of the Raman and IR bands of paracetamol were analyzed.In chapter 3,the fundamental structures of Chitosan were calculated with the DFT and Monte Carlo Method to obtained their optimized structures.In chapter 4, all the results obtained in this thesis were summarized, and the possibilities for future works were described.