Mechanism investigation of the reaction between triphenylphosphine, dialkyl acetylenedicarboxylates and 2-hydroxybenzimidazole: Experimental and theoretical study

Arabian Journal of Chemistry

B. Makiabadi¹  H. Ghasempour²  M. Zakarianezhad³  M.T. Maghsoodlou⁴  S.M. Habibi-Khorassani⁴ 

[1] Department of Chemical Engineering, Sirjan University of Technology, Sirjan, Iran;Department of Chemistry, Bardsir Branch, Islamic Azad University, Bardsir, Iran;Department of Chemistry, Payam Noor University, Tehran, Iran;Department of Chemistry, The University of Sistan and Baluchestan, Zahedan, Iran;

关键词: Stable phosphorus ylides;    Kinetic study;    Z and E rotamers;    AIM analysis;   

DOI  :  10.1016/j.arabjc.2012.12.012

来源: DOAJ

【 摘 要 】

In the recent work, NMR study and the stability of the Z- and the E- isomers were undertaken for the two rotational isomers of phosphorus ylides involving 2-hydroxybenzimidazole [namely dimethyl-2-(2-hydroxybenzimidazole-n-yl)-3-(triphenylphosp hanylidene) succinate] by natural population analysis (NPA) and atoms in molecules (AIM) methods. Quantum mechanical calculation was clarified how the ylides exist in solution as a mixture of the two geometrical isomers (Z- and E-) as a minor or major form. In addition, Kinetic studies were performed for the reaction between triphenylphosphine and dialkyl acetylenedicarboxilate in the presence of NH– heterocyclic compound, such as 2-hydroxybenzimidazole. To determine the kinetic parameters of the reaction, it was monitored by UV spectrophotometry. Useful information was obtained from studies of the effect of solvent and concentration of reactants on the rate of reaction. Proposed mechanism was confirmed according to the obtained results and steady state approximation and first step (k2) and third step of reaction were recognized as a rate determining step and fast step, respectively on the basis of experimental data.

【 授权许可】

Unknown