Structure to property relationships for multiphoton absorption in covalently linked porphyrin dimers: a correction vector INDO/MRDCI study.
The correction vector method has been used to investigate structure to property relationships for multiphoton absorption properties in covalently linked porphyrin dimers. The electronic structure of the system is described within the multireference single and double configuration interaction (MRDCI) method coupled with the intermediate neglect of differential overlap (INDO) Hamiltonian. We find a strong increase in the two-photon absorption (2PA) and three-photon absorption (3PA) cross sections when going from an isolated porphyrin to the dimers. The nature of the 2PA and 3PA active states as well as the cross sections show a strong but not straightforward dependence on the length of the bridge between the two porphyrins. Our theoretical results are in very good agreement with experimental data for 2PA. The resulting structure to property relationships are analyzed on the basis of essential-state models, where it turns out that a three-state model considering only the Q(x) intermediate state proposed in literature does not provide a full description of the actual situation.
Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, P. R. China.
Lingyun
L
Zhu
Yuanping
Y
Yi
Zhigang
Z
Shuai
Karin
K
Schmidt
Egbert
E
Zojer