Article,

Exceptionally variable solvatochromism of centrosymmetric octacarbonyldimolybdenum(0) complexes. Rules to estimate the solvent sensitivity of charge-transfer absorption energies

, and .
Inorganic Chemistry, 25 (18): 3306--3310 (1986)
DOI: 10.1021/ic00238a040

Abstract

Solvent sensitivities varying by a factor of \textgreater6 were obsd. for the metal-to-ligand charge-transfer (MLCT, p* $łeftarrow$ d) absorption bands in 4 (m-L)Mo(CO)42 complexes, where m-L are the doubly bidentate bridging ligands 2,2'-bipyrimidine (bpym), 2,5-bis(2-pyridyl)pyrazine (dppz), 3,6-bis(2-pyridyl-1,2,4,5-tetrazine (dptz), and azo-2,2'-bipyridine (abpy). Although the binuclear complexes are centrosym. and should, therefore, not possess a permanent dipole moment, they exhibit stronger solvatochromism than their mononuclear, noncentrosym. analogs. The variable solvatochromic behavior of these complexes was understood by considering the importance of dispersion interactions in such complexes; changes in mol. polarizability between the resp. ground and MLCT excited states depend strongly on the differences in s donation from the a-diimine ligand in the neutral and anion radical forms and on the possible degeneracy of the ligand p* MO. Some general guidelines are given that allow estn. of the extent of MLCT absorption band solvent sensitivities from the properties of the ligands and the metal fragments. on SciFinder(R)

Tags

Users

  • @b_schwederski
  • @huebleriac

Comments and Reviews