114944-18-2Relevant academic research and scientific papers
Low-valent cyanocobaltate chemistry. 3. Reactions of [(η5-C5H5)Co(CN)(CO)]- with electrophiles, nucleophiles, and redox agents. Synthesis of new (η5-cyclopentadienyl)cobalt cyanide complexes
Carter, Stephen J.,Stuhl, Louis S.
, p. 1909 - 1918 (2008/10/08)
Details of the syntheses and reactivity of (K-crown)[Cp(CN)(CO)] (1a) (crown = 18-crown-6 ether), PPN[Cp(CN)(CO)] (1b), (K-crown)[CpCo(CN)PPh3] (4), and (K-crown)[CpCo(CN)2] (10a) are presented. Compound 1a is readily formed by reaction of CpCo(CO)2 with cyanide in aprotic media. Reaction of CpCo(CO)2 with excess cyanide under forcing conditions results in the dissociation of cyclopentadienide anion instead of [CpCo(CN)2]2- formation. Although the [CpCo(CN)2]2- anion appears to be extremely basic and reactive, an impure form can be isolated by the low-temperature reduction of 10a in DMF. The electrophiles acetyl chloride, benzyl bromide, and methyl fluorosulfate do not react with 1a to form isocyanides but unexpectedly produce CpCo(CO)2 and a variety of Co(II) and Co(III) compounds. The pathways that culminate in these products are suggested to originate from an initial one-electron transfer yielding the intermediate [Cp(CN)(CO)]. Treatment of 1a or 1b with tosyl chloride yields [CpCo-(CN)2(η1-SO2C6H 4CH3)]- and cyanide-bridged cyclopentadienylcobalt(III) polymers, while 1a or 1b reacts cleanly with R3SnCl reagents to form the expected isocyanide complexes. Hg(CN)2 oxidizes 1 to CpCo(CN)3-. Acyl chlorides lacking α-hydrogens react with 1 to produce novel bis(acyl isocyanide) complexes CpCo-(CNCOR)2 in low yields. The spectroscopic characterization of these compounds is presented, and the nature of the cyanide ligand's influence on low-valent metal centers is discussed.
