ELECTRONIC-STRUCTURES OF ORGANOMETALLIC COMPLEXES OF F-ELEMENTS - PART 45 - COMPARISON OF PHENOMENOLOGICAL AND CALCULATED CRYSTAL-FIELD PARAMETERS OF LANTHANIDE ORGANYLS ESTIMATED ON THE BASIS OF SIMPLE-MODELS

The crystal field (CF) parameters of Nd[N(SiMe3)(2)](3), (THF)(3)Li(mu -Cl)Nd[N(SiMe3)(2)](3) and Nd[N (SiMe3)(2)](3)(CNC6H11)(2) (which are considered as model compounds for the corresponding sigma-bonded organ ometallic complexes with [CH(SiMe3)(2)](-) ligands), as well as those of organometallic pi complexes of the types (Me3SiC5H4)(3)Pr and (C8H8 )Pr[HB(3,5-Me(2)pz)(3)], were estimated on the basis of simple model c alculations (point charge electrostatic model, simple overlap model, a ngular overlap model) and were compared with the results of CF calcula tions adopting the phenomenological model. The comparison suggests tha t these straightforward model calculations may provide satisfactory CF parameters for a complexes but give poor results for sigma complexes of the lanthanides. (C) 1998 Elsevier Science B.V. All rights reserved .