Low-Valent Chemistry of Cobalt Amide. Synthesis and Structural Characterization of Cobalt(II) Amido, Aryloxide, and Thiolate Compounds

The binuclear cobalt(II) amide complex [(CoL2)2·(TMEDA)] (1) [L = N(SitBuMe2)(2-C5H3N-6-Me); TMEDA
= Me2NCH2CH2NMe2] has been synthesized by the reaction of anhydrous CoCl2 with 2 equiv of [Li(L)(TMEDA)].
X-ray crystallography revealed that complex 1 consists of two {CoL2} units linked by one TMEDA ligand molecule,
which binds in an unusual N,N‘-bridging mode. Protolysis of 1 with the bulky phenol ArMeOH (ArMe = 2,6-tBu2-4-MeC6H2) and thiophenol ArSH (Ar = 2,4,6-tBu3C6H2) gives the neutral monomeric cobalt(II) bis(aryloxide)
[Co(OArMe)2(TMEDA)] (2) and dithiolate [Co(SAr)2(TMEDA)] (3), respectively. Complexes 1−3 have been
characterized by mass spectrometry, microanalysis, magnetic moment, and melting-point measurements, in addition
to X-ray crystallography.