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Tetrazine Chelate Ligands Bridging Two [Ru(acac) 2 ] Fragments: Mixed Valency and Radical Complex Formation
Author(s) -
Kaim Wolfgang,
Löw Isabell,
Ringenberg Mark R.,
Schwederski Brigitte,
Filippou Vasileios,
Fiedler Jan
Publication year - 2022
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.202200152
Subject(s) - comproportionation , tetrazine , chemistry , electron paramagnetic resonance , valency , chelation , crystallography , electron acceptor , medicinal chemistry , inorganic chemistry , photochemistry , electrochemistry , organic chemistry , linguistics , physics , philosophy , electrode , nuclear magnetic resonance
Using bis(3‐methyl‐2‐pyridyl)‐1,2,4,5‐tetrazine 1 , 3‐(2‐pyrimidyl)‐6‐methyl‐1,2,4,5‐tetrazine 2 and bis(2‐pyrimidyl)‐1,2,4,5‐tetrazine=bmtz as ligands, the complexes 3 =[Ru(acac) 2 ( 1 )], 4 ={[Ru(acac) 2 ] 2 ( 1 )], 5 ={[Ru(acac) 2 ] 2 (bmtz)], and 6 ={[Ru(acac) 2 ] 2 ( 2 )] were prepared and identified by structure analysis of crystallized material. The one‐electron oxidized form 6 (PF 6 ) was also studied structurally, suggesting a Class II mixed‐valent situation. The neutral dinuclear systems exhibit two reversible oxidation processes with comproportionation constants 10 9.2 < K c <10 14.1 and one reduction which were analyzed UV/vis/NIR and EPR spectroscopically. Oxidation produces largely metal‐based mixed‐valent cations with very weak intervalence absorptions in the near IR whereas the electron uptake occurs at the tetrazine acceptor.