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Charge‐Transfer Salts of Ferrocene Derivatives with Bis(maleonitriledithiolato)metallate(III) Complexes ([M(mnt) 2 ] − , M=Ni, Pt): A Ground‐State High‐Spin [(Ni(mnt) 2 ) 2 ] 2− Dimer
Author(s) -
Zürcher Stefan,
Petrig Jeannine,
Perseghini Mauro,
Gramlich Volker,
Wörle Michael,
von Arx Dieter,
Togni Antonio
Publication year - 1999
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/(sici)1522-2675(19990908)82:9<1324::aid-hlca1324>3.0.co;2-f
Subject(s) - ferrocene , chemistry , dimer , medicinal chemistry , polymer chemistry , electrochemistry , organic chemistry , electrode
New hexamethylated ferrocene derivatives containing thioether moieties (1,1′‐bis[( tert ‐butyl)thio]‐2,2′,3,3′,4,4′‐hexamethylferrocene ( 3a , b )) or fused S‐heteropolycyclic substituents ( rac ‐1‐[(1,3‐benzodithiol‐ 2‐yliden)methyl]‐2,2′,3,3′,4,4′‐hexamethylferrocene ( 5 ) and rac ‐1‐[1,2‐bis(1,3‐benzodithiol‐2‐yliden)ethyl]‐2,2′,3,3′,4,4′‐hexamethylferrocene ( 14 )), as well as a series of ferrocene‐substituted vinylogous tetrathiafulvalenes (1,1′‐bis[1,2‐bis(1,3‐benzodithiol‐2‐yliden)ethyl]ferrocene ( 6a ), 1,1′‐bis[1‐(1,3‐benzodithiol‐2‐yliden)‐2‐(5,6‐dihydro‐1,3‐dithiolo[4,5‐ b ] [1,4]dithiin‐2‐yliden)ethyl]ferrocene ( 6b ), [1,2‐bis(1,3‐benzodithiol‐2‐yliden)ethyl]ferrocene ( 21a ), [1‐(1,3‐benzodithiol‐2‐yliden)‐2‐(5,6‐dihydro‐1,3‐dithiolo[4,5‐ b ] [1,4]dithiin‐2‐yliden)ethyl]ferrocene ( 21b ), [1,2‐bis(5,6‐dihydro‐1,3‐dithiolo[4,5‐ b ] [1,4]dithiin‐2‐yliden)ethyl]ferrocene ( 21c ), [1‐(5,6‐dihydro‐1,3‐dithiolo[4,5‐ b ] [1,4]dithiin‐2‐yliden)‐2‐(1,3‐benzodithiol‐2‐yliden)ethyl]ferrocene ( 21d )) were prepared and fully characterized. Their redox properties show that some of them are easily oxidized and undergo transformation to paramagnetic salts containing bis(maleonitriledithiolato)‐metallate(III) anions [M(mnt) 2 ] − (M=Ni, Pt; bis[2,3‐dimercapto‐ κ S)but‐2‐enedinitrilato(2 − )]nickelate (1 − ) or ‐platinate (1 − ). The derivatives [ 3a ] [Ni(mnt) 2 ] ( 26 ), [ 3a ] [Pt(mnt) 2 ] ( 27 ), [Fe{( η 5 ‐C 5 Me 4 S) 2 S}] [Ni(Mnt) 2 ] ( 28 ), [Fe{( η 5 ‐C 5 Me 4 S) 2 S}] [Pt(mnt) 2 ] ( 29 ), [ 5 ] [Ni(mnt) 2 ]⋅ClCH 2 CH 2 Cl ( 30 ), [ 6a ] [Ni(mnt) 2 ] ( 31 ), [ 6a ] [Ni(mnt) 2 ]⋅ClCH 2 CH 2 Cl ( 31a ), [ 6a ] [Pt(mnt) 2 ] [ 32 ), and [ 6b ] [Ni(mnt) 2 ] ( 33 ) were prepared and fully characterized, including by SQUID (superconducting quantum interference device) susceptibility measurements. X‐Ray crystal‐structural studies of the neutral ferrocene derivatives 6a , b , 21c , d , and 1,1′‐bis[1‐(1,3‐benzodithiol‐2‐yliden)‐2‐oxoethyl]ferrocene ( 23 ), as well as of the charge‐transfer salts 26 – 28 , 30 , and 31a , are reported. The salts 28 and 30 display both a D + A − A − D + structural motif, however, with a different relative arrangement of the [{Ni(mnt) 2 } 2 ] 2− dimers, thus giving rise to different but strong antiferromagnetic couplings. Salt 26 exhibits isolated ferromagnetically coupled [{Ni(mnt) 2 } 2 ] 2− dimers. Salt 27 displays a D + A − D + A − structural motif in all three space dimensions, and a week ferromagnetic ordering at low temperature. Salt 31a , on the contrary, shows segregated stacks of cations and anions. The cations are connected with each other in two dimensions, and the anions are separated by a 1,2‐dichloroethane molecule.