TY - JOUR
T1 - Three-dimensional through-space/through-bond derealization in cyclophane systems
T2 - A molecuie-in-molecule approach
AU - Lin, Hsin-Chieh
AU - Jin, Bih Yaw
PY - 2008/4/3
Y1 - 2008/4/3
N2 - In this article, we propose a simple strategy to identify the nature of excitonic couplings in a series of cyclophanedienes based on the "molecule-in-molecule" (MIM) theory. The contributions of charge-transfer (CT) exciton, unavailable by the commonly used supermolecular approach due to the inadequate basis set, can be unambiguously identified within this methodology. Combining the CT contributions calculated on the cyclophanedienes and the corresponding hypothetical molecules with tethers removed, one can infer the information on the relative importance of through-bond and through-space contributions in the low-lying excited states. Particularly, we discovered that the tether effect for the meta-linkage cyclophanedienes is crucial, whereas those for para-linkage cyclophanedienes are vanishingly small. The changes in the coupling between two moieties for both the six-membered meta-linkage and five-membered cyclophanedienes arise primarily from an increase in the through-bond charge-transfer component of the coupling (>70%). Within the MIM model, the derealization pathway of the dimer in the excited state can be explained quantitatively by a CT exciton, which differs from the approach based on the conventional orbital interaction analysis.
AB - In this article, we propose a simple strategy to identify the nature of excitonic couplings in a series of cyclophanedienes based on the "molecule-in-molecule" (MIM) theory. The contributions of charge-transfer (CT) exciton, unavailable by the commonly used supermolecular approach due to the inadequate basis set, can be unambiguously identified within this methodology. Combining the CT contributions calculated on the cyclophanedienes and the corresponding hypothetical molecules with tethers removed, one can infer the information on the relative importance of through-bond and through-space contributions in the low-lying excited states. Particularly, we discovered that the tether effect for the meta-linkage cyclophanedienes is crucial, whereas those for para-linkage cyclophanedienes are vanishingly small. The changes in the coupling between two moieties for both the six-membered meta-linkage and five-membered cyclophanedienes arise primarily from an increase in the through-bond charge-transfer component of the coupling (>70%). Within the MIM model, the derealization pathway of the dimer in the excited state can be explained quantitatively by a CT exciton, which differs from the approach based on the conventional orbital interaction analysis.
UR - http://www.scopus.com/inward/record.url?scp=47149092377&partnerID=8YFLogxK
U2 - 10.1021/jp0763127
DO - 10.1021/jp0763127
M3 - Article
C2 - 18302348
AN - SCOPUS:47149092377
VL - 112
SP - 2948
EP - 2954
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 13
ER -