Hydrogen bond effects in the ground and excited singlet states of 4H-1-benzopyrane-4-thione in water-theory and experiment
Hydrogen bond effects in the ground and excited singlet states of 4H-1-benzopyrane-4-thione in water-theory and experiment
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DOI：
10.1039/c2cp23869a
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发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Maciejewski, Andrzej
中科院分区：
文献类型：
--
作者：
Krystkowiak, Ewa;Koput, Jacek;Maciejewski, Andrzej
用从头算方法测定了4H-1-苯并吡喃-4-硫酮(BPT)的基态和两个最低激发态的氢键能。结果表明，BPT分子作为受体可以与水分子形成四个较强的氢键，形成稳定的基电子态络合物S-0。硫代羰基硫原子的氢键比苯并吡喃部分氧原子的氢键强。以前的氢键在激发到S-1态时会明显减弱，相反，在激发到S-2态时会变得更强。由S-0>；S-1和S-0>；S-2激发引起的氢键能变化的计算结果，与我们在[E.Krystkowiak，等，J.PhotoChem]中提出的吸收溶剂变色研究的实验值符合得很好。光生物醇。答：化学，2006,184,250]。考虑非特定溶质-溶剂相互作用的BPT-水氢键络合物的吸收光谱极大值也与实验结果吻合较好。
The hydrogen bond energies for 4H-1-benzopyrane-4-thione (BPT) in its ground and two lowest excited singlet electronic states have been determined using ab initio methods. It was shown that the BPT molecule can form, as an acceptor, four relatively strong hydrogen bonds with water molecules, leading to a stable complex in the ground electronic state S-0. The hydrogen bonds involving the sulfur atom from the thiocarbonyl group were found to be stronger than those involving the oxygen atom from the benzopyran moiety. The former hydrogen bonds were predicted to become significantly weaker upon excitation to the S-1 state and, in contrast, stronger upon excitation to the S-2 state. Calculated changes in the hydrogen bond energy due to the S-0 -> S-1 and S-0 > S-2 excitation are in very good agreement with the experimental values obtained from the absorption solvatochromic study, according to a procedure proposed by us in [E. Krystkowiak, et al., J. Photochem. Photobiol. A: Chem., 2006, 184, 250]. The maxima of absorption spectra of the BPT-water hydrogen-bonded complex, calculated taking into consideration nonspecific solute-solvent interactions, are also in good agreement with the experimental results.