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Tetrapyridine and Tetrapyrazine TTF Derivatives: Synthesis, Characterization and Preparation of a Bimetallic Co II Complex
Author(s) -
Dias Sandra I. G.,
Neves Ana I. S.,
Rabaça Sandra,
Santos Isabel C.,
Almeida Manuel
Publication year - 2008
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/ejic.200800660
Subject(s) - chemistry , tetrathiafulvalene , bimetallic strip , pyrazine , pyridine , redox , crystallography , antiferromagnetism , bridging ligand , crystal structure , ligand (biochemistry) , single crystal , medicinal chemistry , stereochemistry , inorganic chemistry , metal , organic chemistry , molecule , biochemistry , physics , receptor , condensed matter physics
The tetra‐substituted TTF‐type donors 4,4′,5,5′‐tetrakis(2‐pyridylethylsulfanyl)tetrathiafulvalene ( 1 ) and 4,4′,5,5′‐tetrakis(2‐pyrazylethylsulfanyl)tetrathiafulvalene ( 2 ) were prepared and characterized. These donors show a redox behaviour that is comparable with similar unsubstituted TTF donors, with a small increase of the redox potentials due to the electron‐withdrawing effect of the pyridine and pyrazine groups. Single crystal X‐ray diffraction analyses show structures with a strong segregation of TTF and azo moieties. The pyridine‐substituted donor 1 was used as a bridging ligand to prepare a dinuclear Co II ‐coordination complex [ 1 Co 2 (hfac) 4 ] (hfac = hexafluoroacetylacetonate) with redox properties identical to that of 1 . This dinuclear complex presents an effective magnetic moment of ca. 8 μ B , corresponding to nearly independent S = 3/2 spins with weak antiferromagnetic interactions below 65 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)