Coupling Reactions of Ferrocenylacetylene with Mononuclear Metal Carbonyls Fe(CO)₅ and M(CO)₆ (M = Mo, W):  Synthesis and Characterization of [Fe(CO)₂{η⁵-2,5-Fc₂C₅H₂CO}C(Fc)CH], [Fe(CO)₂{η²:η²-2,5-Fc₂C₄H₂Fe(CO)₃}-μ-CO], [Fe(CO)₃{η²:η²-2,5-Fc₂C₄H₂CO}], 1,2,4-Triferrocenylbenzene, 2,5-Diferro

Abstract

Thermolysis of a benzene solution containing Fe(CO) 5 and ferrocenylacetylene yielded three new compounds: [Fe(CO) 2 {η 5 -2,5-Fc 2 C 5 H 2 CO}C(Fc)dCH] (1), [Fe(CO) 2 {η 2 :η 2 -2,5-Fc 2 C 4 H 2 -Fe(CO) 3 }-µ-CO] (2), and [Fe(CO) 3 {η 2 :η 2 -2,5-Fc 2 C 4 H 2 CO}] (3). When a benzene solution containing ferrocenylacetylene and M(CO) 6 (M ) Mo, W) was refluxed, 1,2,4-triferrocenylbenzene (4) was formed. In contrast to the reaction of ferrocenylacetylene with Fe(CO) 5 , which leads to cyclization with insertion of a CO molecule, in the reaction with M(CO) 6 no insertion of CO takes place during cyclization. However, if the reactions with M(CO) 6 are carried out in the presence of S 8 -powder or Se-powder, insertion of these chalcogen atoms during cyclization does take place and 2,5-diferrocenylthiophene (5) and 2,5-diferrocenylselenophene (6) are formed respectively, along with 4. All new compounds were characterized by IR and 1 H and 13 C NMR spectroscopy. Structures of 1-5 were established by singlecrystal X-ray crystallography.

The synthesis and electrochemistry of 2,5-dimethylazaferrocenes with heteroaryl bridges

“…The final steps involve formation of the benzo [b]thiophene and benzo [b]selenophene bridging fragments by the ring-closure of ortho diferrocenoylbenzene with Lawesson's reagent or selenating reagents. A simpler strategy toward the synthesis of complex 1 comprises the thermolysis of ethynylferrocene in the presence of mononuclear metal carbonyls and elemental sulfur in benzene solution [12]. However, the most straightforward and universal approach is represented by palladium catalyzed cross-coupling reactions of ferrocenylzinc chloride and dihaloheteroarenes.…”

“…Potentials are given against the ferrocene/ferrocenium couple. The splittings of half-wave potentials were directly taken from the CVs, square wave and differential pulse voltammograms (12) or by deconvolution of the overlapping peaks in square wave and differential pulse voltammetry (13,14). DE 1/2 values were independently calculated from the CV peak potential separations and forward wave half-widths by the method of Richardson and Taube [11].…”

“…With this in mind we here report on the synthesis and electrochemical characterization of the three novel 2,5-dimethylazaferrocenyl substituted derivatives 2,5-di(1 0 -(2,5-dimethylazaferrocenyl))thiophene (12), 2,6-di(1 0 -(2,5-dimethylazaferrocenyl))pyridine (13) and 5,5 0 -di(1 0 -(2,5-dimethylazaferrocenyl))-2,2 0 -bithiophene (14). Complexes 12 and 13 are close relatives of compounds 1 and 3.…”

Photochemical reactions of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe(CO)5 and CO

“…The C(7)eC(8) and C(27)eC(28) bond distances of 1.432(7) and 1.455(7) Å, respectively are lengthened from the normal C]C double bond distance due to complexation, and these are also longer than the corresponding distances of the metallocycopentadiene ring of [Fe 2 (CO) 6 (C 4 H 2 Fc 2 )], [Ru 2 (CO) 6 (C 4 H 2 Fc 2 )], and [Ru 2 (CO) 6 {C 4 Fc 2 (C^CFc) 2 }] [11]. In general, the metallacyclopentadiene ring in 1 is similar to that in [Fe 2 (CO) 6 C 4 H 2 Fc 2 ] [10], [Ru 2 (CO) 6 (C 4 H 2 Fc 2 )] [15], and [Ru 2 (CO) 6 -{C 4 Fc 2 (C^CFc) 2 } 2 ] [11], which are formed in the theromolysis reaction of FcC^CH and Fe(CO) 5 , FcC^CH and Ru 3 (CO) 12 and in the photolysis of FcC^CC^CFc and Ru(CO) 5 respectively.…”

“…When M 3 (CO) 10 (NCMe) 2 (M ¼ Os or Ru) react with diynes 1,4-dialkyl-1,3-butadiyne (alkyl ¼ ferrocenyl, Me, Et, Ph, Bu t , SiMe 3 ) trinuclear or tetranuclear clusters in which only one alkyne group coordinates are formed [12,13]. The free alkyne of cluster can be further used for cluster growth reactions as reported in the formation of the hexanuclear cluster [Ru 6 (m 5 -h 1 :h 1 :h 1 :h 2 :h 2 -PhCHC 3 C 6 H 4 )(m 4 -h 1 :h 1 :h 2 : h 2 ePhCHC 3 C 6 H 4 )(CO) 15 ] [14].…”