MO calculations on the absorption spectra of organic dimers. The interaction energy between dipole moments of electronic transitions in monomers and the shape of absorption bands

✍ Scribed by K.Ya. Burshtein; A.A. Bagatur'yants; M.V. Alfimov

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 359 KB
• Volume: 239
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00443-8

✦ Synopsis

The interaction energy between dipole moments of electronic transitions in the monomers and the shape of absorption bands of organic dimers are calculated by the CNDO/S-CI method. It is found that the through-space resonance interaction between ~r orbitals of the monomers has a strong effect on the shifts and widths of absorption bands of dimers with the structure of H-aggregates. A large intermediate region of structures is found between structures corresponding to H-and J-aggregates. In the intermediate region, the interaction energy between the dipole moments of electronic transition in the monomers is small, and the dimer has a broad unshifled spectral band similar to that of the monomers. The large size of the intermediate region is due to a violation of the point-dipole approximation.