Adducts of Ferrocenylboranes and Pyridine Bases: Generation of Charge-Transfer Complexes and Reversible Coordination Polymers

C5H4BR2 Bending in Ferrocenylboranes: A Delocalized Through‐Space Interaction Between Iron and Boron

“…Mono‐ ([Fc{B(R 1 )(R 2 )}]; Fc=(C 5 H 5 )Fe(C 5 H 4 ))1 and 1,1′‐diborylated ferrocenes (1,1′‐[fc{B(R 1 )(R 2 )} 2 ]; fc=(C 5 H 4 ) 2 Fe)2 are highly interesting redox‐active Lewis acids that have already found applications in various areas of research, for example, oligonuclear metallocene aggregates,3, 4 charge‐transfer polymers,5–7 difunctional chelators of Lewis bases,8–10 ferrocene‐based tris(1‐pyrazolyl)borate ligands,11–14 BN‐ or BP‐bridged ansa ‐ferrocenes,15–18 and 1,3‐dibora[3]ferrocenophanes 19. This area of research was reviewed recently 20.…”

“…21 In all these cases, the question of whether a pronounced electronic interaction between the ferrocenyl moiety and the boryl substituent(s) exists is of prime importance. Evidence has been gathered that tetracoordination of boron in [Fc(BR 2 )] greatly facilitates iron oxidation 5. Moreover, a crystal structure analysis of [Fc(BBr 2 )] (two crystallographically independent molecules in the asymmetric unit) showed the BBr 2 group to be bent towards the iron atom by a dip angle α * of 17.7° (molecule I) and 18.9° (molecule II; α *=180°− α , whereby α is the angle between the geometric center of the carbon atoms constituting the substituted cyclopentadienyl ring, the ipso carbon atom C ipso , and the boron atom) 22.…”

1,1′-(1-Propene-1,3-diyl)-ferrocene: modified synthesis, crystal structure, and polymerisation behaviour

“…3a can be chemically oxidized to green [3a] þ [CF 3 SO 3 ] À using AgCF 3 SO 3 ; the visible absorption spectrum of the salt shows an absorption at 613 nm ( max 830 M À1 cm À1 ) in dichloromethane, similar to that of unsubstituted ferrocenium [31].…”

Synthesis and oxidation of hexafluoroisopropoxyborylferrocenes

“…The ferrocenylborates on the basis of tris(1-pyrazolyl)borates can be assembled to heterooligometallic complexes and polymers to explore novel magnetic and conducting compounds [5][6][7][8]. Ferrocenylboranes linked via B-N bonds and bifunctional pyridine bases (4,4'-bipyridene or pyrazine) lead to charge-transfer polymers [9][10][11]. The charge-transfer interaction occurs between the ferrocene donor and the electronpoor B-N adduct bridge.…”