Hiroshi OKAMOTO, Ashish CHAINANI, Takashi TAKAHASHI (Tohoku Univ.), Hiroshi KITAGAWA, Tadaoki MITANI (JAIST), Toshio MANABE (Nagoya Univ.) and Masahiro YAMASHITA (Nagoya Univ. and IMS)
[Synth. Met. 86, 2136 (1997)]
The electronic structure of the 1-D Ni complexes, [Ni(chxn)2X]X2 (X=Br, Cl) is studied together with discrete Ni complexes, [NiX2([14]aneN4)]ClO4 (X=Br, Cl), using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). An analysis using a simple X-Ni-X trimer model on the Ni 2p XP spectra yields quantitative estimates for the charge transfer (CT) energy (DELTA) and the transfer energy T. An analysis on the Ni LVV Auger spectra indicates that the average on-site Coulomb energy U in these Ni complexes is about 5 eV. The obtained results demonstrate that the 1-D Ni complexes are CT insulators.