Mixed valence interactions in di-.mu.-oxo bridged manganese complexes

Abstract

spectra at higher temperatures; in fact, for several H4WL4 tungsten complexes, where L is a phosphine or arsine ligand, the nonrigidity limit is reached above room temperature.7 (7) (a) B.

Water oxidation chemistry of photosystem II

“…The effects of Jahn-Teller distortion and non-identical ligands on the exchanging partners are, therefore, expected to be operative for electron exchange in the OEC. 3C complex (bpyZ2,2 0 -bipyridine) on the basis of its EPR and near-IR absorption spectra (Cooper & Calvin 1977;Cooper et al 1978 . Assuming a pre-exponential factor of k B T/h, these barriers translate to rates of 2400-0.1 s…”

Synthesis, Structure, Electronic, Redox, and Magnetic Properties of a New Mixed-Valent Mn-Oxo Cluster: [Mn2III,IVO2(N,Nbispicen)2]3+ (N,Nbispicen =N,N-bis(2-pyridylmethyl)-1,2-diaminoethane)

“…There is still a continuing interest in these compounds due to their relevance to the water-oxidizing enzyme in photosystem II [1] [2] and their redox catalytic properties, as shown with the mixed-valent complex [Mn 2 O 2 (bpy) 4 ] 3ϩ [3] [4] [5] and its 1,10-phenantroline analogue. [4] Similar complexes using linear tetradentate ligands like N,NЈ-bis(2-pyridylmethyl)-1,2-diaminoethane (bispicen) [6] have been prepared in order to study their redox properties in relation to their structures. [7] We report herein the synthesis and characterization of a new dinuclear mixed-valence di-µ-oxo manganese complex with the tetradentate ligand N,N-bis(2-pyridylmethyl)-1,2-diaminoethane (N,Nbispicen), an isomer of bispicen which presents a tertiary amino group as well as a primary amino group instead of the two secondary amino groups in bispicen.…”

High-Pressure Study of Oxo-bridged Mixed-Valent MnIII/MnIV Dimers High-Pressure Study of Oxo-bridged Mixed-Valent MnIII/MnIV Dimers

“…Data collections were taken at 0.18, 1.00, and 2.00 GPa for 1·3CH 3 CN and at 0. 45 were carried out starting from the coordinates obtained from a separate data collection carried out under ambient pressure and T = 150 K using MoK α radiation on a Bruker Smart diffractometer [51]. The anomalous scattering factors and mass absorption coefficients were calculated with WINGX [52].…”