Calculation of the Zerohyphen;Fieldhyphen;Splitting Parameters of the Triplet Dianion of Triphenylene and its Ion Triple

摘要

The results are reported of calculations of the zerohyphen;fieldhyphen;splitting parameterDlpar;Ethinsp;equals;thinsp;0rpar;for the free triplet dianion of triphenylene and ofDandEfor its ion triple with two counterions in 2hyphen;methyltetrahydrofuran. For the free dianion good agreement with experiment is obtained if triplet SCF MO's are used and if configuration interaction andsgr;ndash;pgr;interaction are included according to a semiempirical method proposed by van der Waals and ter Maten. The ESR spectrum of the triplet ion triple does not reflect the trigonal symmetry of triphenylene. To account for this, three different models for the ion triple are considered. The electric fields of the counterions and solvent molecules are represented as the fields of two point charges. Their effect is introduced in the SCF calculations after whichDandEare calculated with allowance for configuration interaction andsgr;ndash;pgr;interaction. A comparison with the experimental results shows that the polarizing influence of the counterions can largely account for the observedDandEvalues.