Zur Elektronenstruktur metallorganischer Komplexe der f‐Elemente. 63 Parametrische Analyse des Kristallfeld‐Aufspaltungsmusters von pseudo trigonal‐planarem Er(η 5 ‐C 5 H 4 tBu) 3

Electronic Structures of Organometallic Compounds of f Elements. 63 Parametric Analysis of the Crystal Field Splitting Pattern of Pseudo Trigonal Planar Er(η 5 ‐C 5 H 4 tBu) 3 The absorption spectrum of presumably pseudo trigonal planar Er(η 5 ‐C 5 H 4 tBu) 3 ( 1 ) has been measured at room and low temperatures. From the spectra obtained, a truncated crystal field (CF) splitting pattern could be derived, and simulated by fitting the parameters of a phenomenological Hamiltonian. For 34 assignments, a reduced r.m.s. deviation of 24.8 cm −1 was achieved. On the basis of the CF parameters used, the global CF strength experienced by the Er 3+ central ion is estimated, and the experimentally based non‐relativistic molecular orbital scheme (in the f range) is set up and compared with the result of an SW‐Xα calculation on the fictive trigonal planar model complex Dy(η 5 ‐C 5 H 5 ) 3 .