caa a22 4500 465808204 CHVBK 20180323112109.0 cr unu---uuuuu 170327e19900501xx s 000 0 eng 10.1007/BF00641329 doi (NATIONALLICENCE)springer-10.1007/BF00641329 Kuz'mitskii V. B. I. Stepanov Institute of Physics, Belorussian SSR Academy of Sciences, Minsk aut Application of perturbation theory to the description of the lowest excited states of porphyrin molecules [Elektronische Daten] [V. Kuz'mitskii] Consideration has been given to the effect of one-electron perturbation on the energy of the lowest excited singlet and triplet states of high symmetry (D4h) of porphyrins, corresponding to the transfer of an electron from the pair of quasi-degenerate highest occupied MO a1u and a2u to the pair of degenerate unoccupied MO eg. It is assumed that the MO considered satisfy the SCF equation. With the help of orthogonal transformations of the highest occupied and lowest unoccupied MO it is shown that the secular fourth-order problems for the S- and T-states have exact solutions. By comparing with experimental data and with the results of quantum-chemical calculations for the S1, S2 and T1-levels the accuracy of the results obtained has been analyzed for two series of compounds (metal complexes of the azaporphyrins, and compounds with different numbers and positions of the central hydrogen atoms). Plenum Publishing Corporation, 1990 Theoretical and Experimental Chemistry Kluwer Academic Publishers 26/3(1990-05-01), 239-249 0040-5760 26:3<239 1990 26 11237 https://doi.org/10.1007/BF00641329 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00641329 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Kuz'mitskii V. B. I. Stepanov Institute of Physics, Belorussian SSR Academy of Sciences, Minsk aut NATIONALLICENCE 773 0- Theoretical and Experimental Chemistry Kluwer Academic Publishers 26/3(1990-05-01), 239-249 0040-5760 26:3<239 1990 26 11237 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer