Notizen: NQR-Untersuchungen an Charge-Transfer- Komplexen mit einer N-J-Bindung / NQR-Studies of Charge-Transfer-Complexes Containing a N-I-Bond

Abstract

In a number of charge-transfer-molecules containing a N-I-bond we have found NQR-transition-frequencies of the I-atom adjacent N in the range between 300-970 MHz (Table 1). The used spectrometer works automatically and it is possible to cool the sample with liquid nitrogen even at highest frequencies. We have tried to interpret the results using MO-theory. Especially it was shown that the σ_g-orbital in I-I contributes to the bond in the three-centre-system N-I-I. This fact does not agree with calculations in LCMO-theory, which is the MO-analoge of the Mulliken-VB-theory. According to Mulliken the contribution of the σ_g-orbital of I-I is equivalent to a polarisation of the I-I-molecule interacting with the donor.