Theoretical study of mechanism of extraction reaction between germylene carbene and its derivatives and thiirane |
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Authors: | Xiu Hui Lu Xin Che Le Yi Shi Jun Feng Han Zhen Xia Lian |
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Institution: | School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong 250022, People's Republic of China |
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Abstract: | The mechanism of the sulfur extraction reaction between singlet germylene carbene and its derivatives X2Ge?C: (X = H, F, Cl, CH3)] and thiirane has been investigated with density functional theory, including geometry optimization and vibrational analyses for the involved stationary points on the potential energy surface. The energies of the different conformations are calculated by B3LYP/6‐311G(d,p) method. From the potential energy profile, it can be predicted that the reaction pathway of this kind consists two steps: (1) the two reactants firstly form an intermediate (INT) through a barrier‐free exothermic reaction; (2) the INT then isomerizes to a product via a transition state (TS). This kind reaction has similar mechanism, when the germylene carbene and its derivatives X2Ge?C: (X = H, F, Cl, CH3)] and thiirane get close to each other, the shift of 3p lone electron pair of S in thiirane to the 2p unoccupied orbital of C in X2Ge = C: gives a p → p donor–acceptor bond, leading to the formation of INT. As the p → p donor–acceptor bond continues to strengthen (that is the C? S bond continues to shorten), the INT generates product (P + C2H4) via TS. It is the substituent electronegativity that mainly affects the extraction reactions. When the substituent electronegativity is greater, the energy barrier is lower, and the reaction rate is greater. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 |
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Keywords: | germylene carbene extraction reaction potential energy surface |
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