Diamagnetic versus paramagnetic structure of SPS-type pincer-based Co-I, Rh-I, and Ir-I complexes

作者：Doux M; Le Floch P; Jean Y^*

来源：European Journal of Inorganic Chemistry, 2006, (10): 2035-2039.

DOI：10.1002/ejic.200501075

• group 9
• density functional calculations
• P ligands
• S ligands
• QM/MM

The lowest singlet and triplet states of SPS-type pincer-based [M(SPS)(PPh3)] complexes (M = Co, Rh, and Ir) were studied by means of DFT/B3PW91 calculations on the model complexes in which the nine phenyl substituents were replaced by H atoms. Although the Rh and Ir compounds were found to be diamagnetic with a square-planar geometry, the yet unknown Co complex was predicted to be paramagnetic (Delta E-S/T = -22.4 kcal center dot mol(-1)) with two unpaired electrons localized on the metal center. Three minima were actually located on the triplet potential energy surface that differ by the arrangement of the ligands (nearly tetrahedral or butterfly geometries), two of them being close in energy (Delta E = 2.5 kcal center dot mol(-1)). Finally, the paramagnetism of the Co complex was confirmed by calculations on the real complex at the B3PW91//ONIOM(B3PW91:UFF) level of theory (Delta E-S/T = -29.6 kcal center dot mol(-1)).

• 出版日期2006-5-22