Some Cyclopentadienylcobalt cyanides and isocyanides

Schrittweiser Aufbau von [(C5H5)4(C5Me5)4Co4Rh4(CN)12]4+, einem „metallorganischen Kasten”

“…[5] oder häufiger durch p-Komplexierung über h 2 -, h 4 -, h 6 -oder bisallylische h 3 :h 3 -Wechselwirkungen wie in den Verbindungen [Rh 2 (C 5 Me 5 ) 2 (1,2-h 2 -3,4-h 2 -C 10 H 8 )(PMe 3 ) 2 ], [6] [RhCp(h 4 -C 14 H 10 )], [7] [Ru(h 4 -C 8 H 12 )(h 6 -C 10 H 8 )] [8] und [Fe 2 (CO) 6 (mh 3 :h 3 -C 14 H 10 )]. [9] Eines unserer derzeitigen Ziele ist deshalb, Experimentelles 6' '-4 PF 6 : Eine Lösung von 0.105 g (0.107 mmol) 5' ' in 20 mL CH 3 CN wurde zu einer Lösung von 0.054 g (0.214 mmol) AgPF 6 in 2 mL CH 3 H 3.74, N 6.51;Charge B: C 37.75, H 3.75, N 6.40.…”

CpCo(III) Precatalysts for [2+2+2] Cycloadditions

“…This result points towards a possible different reaction mechanism initiated by the cationic CpCo(III) complex compared to the commonly accepted mechanisms for CpCo complexes [27]. Cationic CpCo(III) complexes can also be synthesized from the dicyano complex 10 by treatment with a strong alkylation reagent [18,21]. Reaction of 10 with trimethyloxonium tetrafluoroborate furnished the dicationic salt 21 with excellent isolated yield (Scheme 10).…”

“…The synthesis results are displayed in Scheme 2. According to the cited reference for the synthesis [21], replacement of the iodides for cyanide groups in the presence of the CO ligand like in complex 1 is not possible, because it would lead to the formation of undesired reaction products. Therefore, the presented sequence of substitution (first CO exchange for the phosphite ligand, then substitution of the iodide for the cyanide) is mandatory.…”

“…Again, substitution of the second CO ligand for a phosphite occurred smoothly for complex 8 as was demonstrated with P(Oi-Pr) 3 . In addition, we realized the exchange of both iodide atoms in compound 2 in the presence of alkali metal cyanide, yielding complex 10 [21,22]. The synthesis results are displayed in Scheme 2.…”

“…The reactivity screening with complex 21 was again undertaken for triynes 16 and 17 (Scheme 11). Cationic CpCo(III) complexes can also be synthesized from the dicyano complex 10 by treatment with a strong alkylation reagent [18,21]. Reaction of 10 with trimethyloxonium tetrafluoroborate furnished the dicationic salt 21 with excellent isolated yield (Scheme 10).…”