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Electron Transfer in Mn‐Tripod Complexes
Author(s) -
Kölle Ulrich,
Englert Ulli
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(20021)2002:1<165::aid-ejic165>3.0.co;2-8
Subject(s) - chemistry , tripod (photography) , electron transfer , octahedron , redox , cyclic voltammetry , homogeneous , reaction rate constant , crystallography , electron , electrochemistry , inorganic chemistry , electrode , kinetics , crystal structure , thermodynamics , physics , optics , quantum mechanics
Abstract A heterogeneous electron‐transfer rate constant k 0 ≈ 7−8 × 10 −7 cm s −1 for the reduction/oxidation of the bis‐tripod complex [CpCo III {P(OEt) 2 O} 3 ] 2 Mn III/II redox couple was measured by cyclic voltammetry. The homogeneous self‐exchange rate was calculated as k 2 = 4.25·10 −3 M −1 s −1 from the cross reaction of the Mn II tripod complex with ferrocenium salt. X‐ray structure determinations for both complexes showed a near regular octahedral oxygen coordination for the Mn II complex and a sizeable Jahn−Teller distortion for the Mn III complex. Applying current ET theory for the comparison of heterogeneous and homogeneous rates and estimates of reorganization energies leads to the conclusion that the major part of the latter is due to inner reorganization of the Mn tripod.