Electronically asymmetric bis(porphyrin) sandwich complexes
- Univ. of Illinois, Urbana, IL (United States)
Bis(porphyrin)metal(IV) complexes (M(porph){sub 2}) have been extensively studies in recent years due to their structural, chemical, and spectroscopic similarity to the {open_quotes}special pair{close_quotes} found in the reaction center of photosynthetic bacteria. Strong interactions arise in the bis(porphyrin) complexes due to the short inter-porphyrin separation (< 3 {angstrom}), which results in properties not seen in mono(porphyrin) analogs. For example, the bis(porphyrin) complexes are considerably easier to oxidize than analogous mono(porphyrin) species, and the M(porph){sub 2{sup n+}} cations (n = 1,2) exhibit near-IR absorptions not found in simple mono(porphyrin)cations. As part of the authors continuing effort to understand the factors that govern the electronic structures of bis(porphyrin) supermolecules, the authors now describe the synthesis of a series of zirconium sandwich complexes. Introduction of electron-withdrawing or -donating groups on the {beta}-pyrrole position considerably affects the electronic properties of these molecules without altering their steric parameters. Thus, peripheral substitution allows modification of the inter-porphyrin {pi} interactions while keeping the inter-porphyrin separation constant. Previous studies have changed the identity of the central metal, but the electronic structure and the interplanar distance could not be varied independently.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 75739
- Journal Information:
- Inorganic Chemistry, Vol. 33, Issue 4; Other Information: PBD: 16 Feb 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
(Porphyrinato)bis(phthalocyaninato)dilanthanide(III) complexes presenting a sandwich triple-decker-like structure
Spectroscopic characterization of lanthanide octaethylporphyrin sandwich complexes. Effects of strong. pi. pi. interaction