Abstract
Reaction of the bis-aminopyridine dianion {[2,6-[2,6-(i-Pr)
2
PhN-C=(CH
2
)]
2
(C
5
H
3
N)]Li(THF)}{Li(THF)
4
} with CoCl
2
(THF)
1.5
under Ar afforded the dinuclear complex {[2,6-(i-Pr)
2
PhN-C=(CH
2
)](C
5
H
3
N)[2,6-(i-Pr)
2
PhN=C(CH
2
)]}
2
[Co(µ-Cl)Li(THF)
3
]
2
·4(THF) (1) in which the ligand is coupled to a second identical unit at a terminal methylene carbon. In turn, the C—C bond formation caused reduction of the Co(II) center to the monovalent state. The same reaction performed under a nitrogen atmosphere afforded the double dinitrogen complex {[2,6-(i-Pr)
2
PhN-C=(CH
2
)](C
5
H
3
N)[2,6-(i-Pr)
2
PhN=C(CH
2
)]}
2
[Co(N
2
)]
2
·2(toluene) (2). Key words: low-valent Co, diiminopyridinato, dinitrogen fixation.