ELECTRON DENSITY DETERMINATION ON [Ni(MNT)2]2- [N(CH3)_4]+2
M. Trenkle1, H. Burzlaff1, H. Kisch2
1Institut für Angewandte Physik,
Lehrstuhl für Kristallographie und Strukturphysik, Universität
Erlangen-Nürnberg, Bismarckstrasse 10, 91054 Erlangen.
2Institut für Anorganische Chemie,
Lehrstuhl für Anorganische und Allgemeine Chemie, Universität
Erlangen-Nürnberg, Egerlandstrasse 1, 91054 Erlangen.
Compounds of the type [MNT-M-MNT]2- [A]2+ (MNT: S2C2(CN)2; M: metal; A: cation) belong to a series of ionic charge-transfer complexes with remarkable semiconductor properties. They show a variation of the specific conductivity in a wide range [1]. It is assumed that this property is due to a change of the electron density distribution within the metallorganic complex.
It has been shown that it is possible to determine the charge density by x-ray diffraction on a compound with M = Ni and A = 2,[N(CH3)4+] (TMA) [2]. However, due to the lack of data at high scattering angles, the electronic structure of the central Ni-atom could not be resolved. Therefore, the expected p-donor bond between the thiolate lone pairs and empty metal acceptor orbitals [3,4] could not be observed.
More precise measurements and results obtained with the program xd [5] will be presented.