CAJ | 학술논문

在B3LYP/6-31G(d,p)和TD B3LYP/6.31++G(d, p)//CIS/6-31G(d, p)水平上,研究了2-(3-巯基-2-吡啶基)苯并咪唑(MPyBI)在气相和七种溶剂(环己烷、苯、三氯甲烷、乙醇、乙腈、二甲亚砜和水)中基态和激发态的分子内质子转移(GSIPT和ESIFT)过程.在基态势能面的研究中发现,该化合物存在分子内双质子转移,其中分步的双质子转移在动力学上具有优势.同时对激发态质子转移势能面及激发态转移过程中的光物理现象进行了研究,结果表明该化合物存在快速的无能垒的激发态分子内质子转移,随着溶剂极性的增强,可以降低基态过渡态的能垒,改变硫醇式与硫酮式互变异构体的比例,从而灵敏地控制荧光的强度.
재B3LYP/6-31G(d,p)화TD B3LYP/6.31++G(d, p)//CIS/6-31G(d, p)수평상,연구료2-(3-구기-2-필정기)분병미서(MPyBI)재기상화칠충용제(배기완、분、삼록갑완、을순、을정、이갑아풍화수)중기태화격발태적분자내질자전이(GSIPT화ESIFT)과정.재기태세능면적연구중발현,해화합물존재분자내쌍질자전이,기중분보적쌍질자전이재동역학상구유우세.동시대격발태질자전이세능면급격발태전이과정중적광물리현상진행료연구,결과표명해화합물존재쾌속적무능루적격발태분자내질자전이,수착용제겁성적증강,가이강저기태과도태적능루,개변류순식여류동식호변이구체적비례,종이령민지공제형광적강도.
The ground-and excited-state intramolecular proton transfer (GSIPT and ESIPT) reactions of 2-(3-mercapto-2-pyridyl) benzimidazole (MPyBI) were studied at the B3LYP/6-31G(d,p) and TD B3LYP/6-31++G(d, p)//CIS/6-31(d, p)levels.The effect of solvents (cyclohexane, benzene, chloroform, ethanol, acetonitrile, dimethylsulfoxide, and water) was investigatexl. We studied the ground-state potential energy surface and discovered a double proton transfer mechanism while a stepwise mechanism was observed to dominate the reaction kinefics.The excited state proton transfer potential energy surface and the photophysical behavior of MPyBl were also studied.Results show that a barrierless ESIPT for MPyBI probably exists and that as the polarity of the solvent increases,the barrier in the GSIPT decreases.When the tautomer ratio is changed,the fluorescence intensity can be easily controlled.