EFFECT OF THE LIGAND-FIELD STRENGTH ON THE RADIATIVE PROPERTIES OF THE LIGAND-LOCALIZED (3)PI-PI(ASTERISK) STATE OF RHODIUM COMPLEXES WITH 1,10-PHENANTHROLINE - PROPOSED ROLE OF DD STATES

In order to quantify the effect of metal d-orbitals on the radiative p roperties of the triplet spin sublevels of the ligand-localized 3pipi State, we have studied the phosphorescence from the ligand-localized 3pipi state of cis-Rh(CN)2(phen)2Cl and Rh(phen)3Cl3 in the crystalli ne state at 1.3 K by optical detection of magnetic resonance (ODMR). T he ODMR experiments show that only the T(x)-spin sublevel is emissive for cis-Rh(CN)2(phen)2Cl, whereas the T(x) and T(z) sublevels are both emissive for Rh(phen)3Cl3. These experimental results are satisfactor ily interpreted in terms of the modulation of the configurational mixi ng of singlet and triplet dpi and dd states with the phen-localized p ipi and sigmapi* states induced by changes in ligand-field strength.