#TITLE_ALTERNATIVE#

• Main Author: ARBA (NIM 20506049), MUHAMMAD
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8695
• Institution: Institut Teknologi Bandung

however reaction mechanism by which the pyrolisis took place has not been understand well. In this computional study, reaction mechanism of syringol pyrolisis using method of MP2//HF and basis set 6-311G(d,p) has been investigated. The pyrolisis took place in three kinds of syringol ring breaking, i.e. ring breaking on carbon bond of 1-2, on carbon bond of 3-4 and on carbon bond of 4-5. Of the three kinds of the reactions, the one that has the lowest activation energy is ring breaking on the carbon bond 1-2 with 103 kcal/mole in energy, whereas the activation energy of the ring breaking on the 3-4 and 4-5 are 263,696 kcal/mole dan 209,641 kcal/mole, respectively. The resulted molecule of the ring breaking on carbon bond of 1-2 undergone subsequently cleavage of carbonyl group followed by cleavage of methanal group with energy each 150,168 kcal/mole and 47,616 kcal/mole. Advanced reaction is cleavage of ethyne group on the carbon bond 5-6 which is the most difficult process of overall reactions indicated by large activation energy as many as 234,263 kcal/mole. The second cleavage of ethyne group took place on the carbon bond 3-4, however the activation energy needed is just 78,778 kcal/mole, much lower than the first reaction. The last step of overall reaction is the formation of carbonyl and methane groups. This process needed 56,307 kcal/mole in energy. In each step of the reaction, we compared data on molecule that still undergone subsequent process using multiplicity of 3 and the same molecule using multiplicity of 1, and the data showed that the molecule using multiplicity of 3 are more stable relatively compared with the molecule using multiplicity 1. Determination of rate constants in each reaction indicate that the cleavage reaction of methanal group in reaction 3 has the highest production rate. In contrast, the the cleavage reaction of ethyne group in reaction 4 will yield lowest product.