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Volumn 126, Issue 7, 2004, Pages 2215-2224

Dynamic Nature of the Intramolecular Electronic Coupling Mediated by a Solvent Molecule: A Computational Study

Author keywords

[No Author keywords available]

Indexed keywords

CHARGE TRANSFER; ELECTRON TRANSITIONS; ELECTRONIC STRUCTURE; ORGANIC SOLVENTS; QUANTUM THEORY;

EID: 1242319476     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja038905a     Document Type: Article
Times cited : (61)

References (100)
  • 70
    • 84986432905 scopus 로고
    • MM3 calculations were performed with the TINKER suite of programs: (a) Dudek, M. J.; Ponder, J. W. J. Comput. Chem. 1995, 16, 791.
    • (1995) J. Comput. Chem. , vol.16 , pp. 791
    • Dudek, M.J.1    Ponder, J.W.2
  • 86
    • 1242326196 scopus 로고    scopus 로고
    • note
    • Since the CT state is shifted to higher energy in the gas-phase calculations, electronic states that are otherwise irrelevant disturb the calculation. The multistate GMH cannot be used either, because it gives an unwanted complete mixing between the excited (non-CT) states and the ground state.
  • 92
    • 1242326195 scopus 로고    scopus 로고
    • note
    • We note, in addition, that not even the "average" conformation of our molecule is rigorously of C, symmetry, since the conformations of the ester groups within A are not mirror-symmetric, in the most stable conformation (from preliminary ab initio calculations on the A fragment) shown in Figure 2.
  • 94
    • 1242281407 scopus 로고    scopus 로고
    • note
    • Autocorrelation function can be evaluated only if the sign of V(t) is computed consistently. The sign of V(t) depends on the sign of the DA orbitals involved in the CT and is arbitrary. However. once assigned it should not change. We used an ad hoe algorithm that locks the sign of the orbital to its value at t = 0. Using this algorithm the TS component for the symmetry-allowed CR coupling always has the same sign. This is the main cause of the non-zero value of the 〈V〉 for the CR process. Moreover. the coupling produced by a solvent molecule placed in two mirror symmetric position is identical for the CR case (leading to 〈V〉 ≠ 0) and opposite in sign for the symmetry-forbidden CS process (leading to 〈V〉 = 0).
  • 95
    • 1242348726 scopus 로고    scopus 로고
    • note
    • Analysis of Figure 3b reveals that more than one characteristic time is involved in the decay of 〈V(t)V(0)〉. The fastest component is ∼0. 1 ps. Further investigation of the slower component is omitted because it is not relevant for the experimentally accessible quantities. High-frequency motions (i.e., vibrations of A9DME) do not modulate the coupling significantly because bond-mediated coupling is small in this system.
  • 96
    • 1242303691 scopus 로고    scopus 로고
    • note
    • We checked that our finding was not due to incomplete sampling of the configurational space by performing repeated simulated annealing from 1000 K. Even when the aryl portion is initially forced into the cavity, the system relaxes to a configuration similar to that of Figure 5. An additional difference with respect to the MeCN and benzene solvent is that the 1,3-DIB molecules are less mobile inside the clamp.
  • 97
    • 1242326197 scopus 로고    scopus 로고
    • note
    • 5N is accompanied by a decrease in the HOMO energy of only 0.5 cV.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.