Solvent-, Cation- and Anion-Induced Structure Variations in Manganese-Based TCNQF 4 Complexes: Synthesis, Crystal Structures, Electrochemistry and Their Catalytic Properties.

Autor: Lu J; School of Chemistry, Monash University, Clayton, VIC, 3800, Australia., Abrahams BF; School of Chemistry, University of Melbourne, Melbourne, VIC, 3010, Australia., Elliott RW; School of Chemistry, University of Melbourne, Melbourne, VIC, 3010, Australia., Robson R; School of Chemistry, University of Melbourne, Melbourne, VIC, 3010, Australia., Bond AM; School of Chemistry, Monash University, Clayton, VIC, 3800, Australia., Martin LL; School of Chemistry, Monash University, Clayton, VIC, 3800, Australia.
Jazyk: angličtina
Zdroj: ChemPlusChem [Chempluschem] 2018 Jan; Vol. 83 (1), pp. 24-34. Date of Electronic Publication: 2017 Dec 12.
DOI: 10.1002/cplu.201700421
Abstrakt: The reaction of Mn(BF 4 ) 2 ⋅x H 2 O with (Pr 4 N) 2 TCNQF 4 (TCNQF 4 =2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) in a mixture of CH 3 OH/CH 2 Cl 2 gives a 2:3 stoichiometric complex of (Pr 4 N) 2 [Mn 2 (TCNQF 4 ) 3 (CH 3 OH) 2 ] (1). If the solvent system used for the crystallisation of 1 is changed to CH 3 OH/DMF, then a different product, [Mn(TCNQF 4 )(DMF) 2 ]⋅(CH 3 OH) 2 (2), is obtained. The use of Li 2 TCNQF 4 instead of (Pr 4 N) 2 TCNQF 4 leads to the generation of [Mn 2 (TCNQF 4 ) 2 (DMF) 4 ]⋅3 DMF (3). An unexpected mixed oxidation state network with a composition of [Mn II 4 Mn III 16 O 10 (OH) 6 (OCH 3 ) 24 (TCNQF 4 ) 2 ](NO 3 ) 2 ⋅24 CH 3 OH (4), is formed if Mn(NO 3 ) 2 ⋅x H 2 O is used in place of Mn(BF 4 ) 2 ⋅x H 2 O in the reaction that leads to the formation of 3. Compounds 1-3 have been characterised by X-ray crystallography; FTIR, Raman and UV/Vis spectroscopy; and electrochemistry. Compound 4 has only been analysed by X-ray crystallography and vibrational spectroscopy (Raman, FTIR), owing to rapid deterioration of the compound upon exposure to air. These results indicate that relatively minor changes in reaction conditions have the potential to yield products with vastly different structures. Compound 1 adopts an anionic 2D network with unusual π-stacked dimers of the TCNQF 4 2- dianion, whereas 2 and 3 are composed of similar neutral sheets of [Mn(TCNQF 4 )(DMF) 2 ]. Interestingly, the solvent has a significant influence on the stacking of the sheets in the structures of 2 and 3. In compound 4, clusters with a composition of [Mn II 4 Mn III 16 O 10 (OH) 6 (OCH 3 ) 24 (CH 3 OH) 4 ] 6+ serve as eight-connecting nodes, whereas TCNQF 4 2- ligands act as four-connecting nodes in a 3D network that has the same topology as fluorite. Compound 3 exhibits an exceptionally high super-catalytic activity for the electron-transfer reaction between ferricyanide and thiosulfate ions in aqueous media.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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