Mixed Valency and The IT Band
Since the energy states of valence tautomers affect the IVCT band, the strength of electronic interaction between the sites, known as α (the mixing coefficient), can be determined by analysis of the IVCT band. Depending on the value of α, mixed valence complexes are classified into three groups:
- class I: α ~ 0, the complex has no interaction between redox sites. No IVCT band is observed. The oxidation states of the two metal sites are distinct and do not readily interconvert.
- class II: 0 < α < = 0.707, intermediate interaction between sites. An IVCT band is observed. The oxidation states of the two metal sites are distinct, but they readily interconvert. This is by far the most common class of intervalence complexes.
- class III: α > = 0.707, interaction between redox sites is very strong. It is better to consider these sites as one united site, not as two isolated sites. An IVCT band is observed. The oxidation states of the two metal sites are essentially equivalent. In these situations, the two metals are often best described as having the same half integer oxidation state.
Read more about this topic: Intervalence Charge Transfer
Famous quotes containing the words mixed and/or band:
“Remember that the wit, humour, and jokes of most mixed companies are local. They thrive in that particular soil, but will not often bear transplanting.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“Nothing makes a man feel older than to hear a band coming up the street and not to have the impulse to rush downstairs and out on to the sidewalk.”
—Robert Benchley (1889–1945)