caa a22 4500 465808123 CHVBK 20180323112108.0 cr unu---uuuuu 170327e19900501xx s 000 0 eng 10.1007/BF00641332 doi (NATIONALLICENCE)springer-10.1007/BF00641332 Electronic absorption spectra or carbonium and dicarbonium ions containing heterocyclic rings with a biphenylene base [Elektronische Daten] [S. Kovalenko, V. Chuev, V. Nikitchenko, M. Asimov] An analysis has been made of π-π* -electronic excitations of carbonium and dicarbonium ions obtained by the interaction of concentrated sulfuric or fluoboric acid with alcohols or glycols containing a heterocyclic bridge structure, i.e., nuclei of dibenzofuran, dibenzothiophene, carbazole, and N-methylcarbazole; this analysis has been aimed at establishing a correlation of their structure and spectral characteristics. From an analysis of experimental data, calculated results, and indexes quantitatively characterizing the structure of the π-π* -electronic excitations, it has been established that there are four electronic transitions in the visible region of the electronic absorption spectrum of the carbonium ions. The long-wave, intense band of the spectrum is due to superposition of intense (p-type) and weak (α-type) transitions proceeding from corresponding excitations of the heterocyclic fragment. In the electronic spectra of the dicarbonium ions, a doublet of p-transitions is clearly manifested. It has been shown that the interaction of chromophores through the bridge structure increases by a factor of approximately 1.8 when the change is made from dibenzofuran to dibenzothiophene, carbazole, and Nmethylcarbazole; in comparison with the corresponding dihydroxycarbonium ions, the degree of interaction of the chromophores is greater by a factor of approximately 1.5. Plenum Publishing Corporation, 1990 Kovalenko S. Khar'kov University, USSR aut Chuev V. Khar'kov University, USSR aut Nikitchenko V. Khar'kov University, USSR aut Asimov M. Khar'kov University, USSR aut Theoretical and Experimental Chemistry Kluwer Academic Publishers 26/3(1990-05-01), 264-270 0040-5760 26:3<264 1990 26 11237 https://doi.org/10.1007/BF00641332 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00641332 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kovalenko S. Khar'kov University, USSR aut NATIONALLICENCE 700 1- Chuev V. Khar'kov University, USSR aut NATIONALLICENCE 700 1- Nikitchenko V. Khar'kov University, USSR aut NATIONALLICENCE 700 1- Asimov M. Khar'kov University, USSR aut NATIONALLICENCE 773 0- Theoretical and Experimental Chemistry Kluwer Academic Publishers 26/3(1990-05-01), 264-270 0040-5760 26:3<264 1990 26 11237 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer