STUDI TEORITIS INTERAKSI SENYAWA 0 KAROTEN DENGAN OKSIGEN SINGLET

• Main Author: Widjajakusuma, Catherina
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/1708
• Institution: Institut Teknologi Bandung

Energy transfer process of interaction of P -carotene and singlet oxygen have been investigated theoretically. All calculations used <br /> conjugated polyenes as an approximation to /3 -carotene. The methods which were used are semiempirical and ab initio method. In semiempirical method, Hiickel molecular orbital (HMO) theory was used to obtain the <br /> highest occupied molecular orbital (HOMO) dan the lowest unoccupied molecular orbital (LUMO), which are tyA. and yr(.) respectively. The bond <br /> order and free valence predict that the edge atoms of polyenes are the most probable atoms which are interact with singlet oxygen. Ab initio method used DALTON 1.2 program package. Calculation of `Ag --> 3 Egtransition <br /> energy in oxygen molecule was done using MCSCF method with 6-311G* basis set, which has result between 116.1763 and 85.6196 kJ/mole. Geometry optimizations of polyenes were carried out at HF-SCF level using a variety of basis set including STO-3G, 3-21G, 6-31G, and 6- 311G. Single point calculations used optimized structure from 6-31G basis set. The calculations of singlet-triplet energy were carried out at MCSCF level and vibration analysis at CI level, both were with STO-3G basis set. These calculations explain how the radiationless transition processes for <br /> longer polyenes (more than three conjugated double bonds).