Synthesis and crystal structures of some cobalt halide derivatives containing alkyl or silanolato groups

Synthesis and Structural Characterization of a Dimeric Cobalt(I) Homoleptic Alkyl and an Iron(II) Alkyl Halide Complex

“…However, the lithium salt of the [C(SiMe 2 Ph) 3 ] − anion apparently effected reduction of the cobalt(II) chloride to give the cobalt(I) product [Co{C(SiMe 2 Ph) 3 }] 2 ( 1 ). This result is in contrast to the reaction of CoCl 2 with the lithium salt of the chelating ligand, [Li{C(SiMe 3 ) 2 (SiMe 2 C 5 H 4 N-2)}], which affords the chloro-bridged dimer [{(2-C 5 H 4 N)Me 2 Si}(Me 3 Si) 2 CCoCl] 2 . The π-complexation of the phenyl ring apparently plays an important role in the stabilization of 1 .…”

“…The Co1–C1 and Co2–C26 bond lengths are 2.037(2) and 2.028(2) Å, respectively. These are somewhat shorter than the Co–C distances in the alkylcobalt(II) halides [{(2-C 5 H 4 N)Me 2 Si}(Me 3 Si) 2 CCoCl] 2 (2.048(4) Å) and [{(Me 2 N)Me 2 Si}(Me 3 Si) 2 CCoBr] 2 (2.065(8) Å) and those in the five-coordinated alkylcobalt(I) complexes [2-(diphenylphosphinyl)tolyl- C , P ]tris(trimethylphosphine)cobalt (2.080(5) Å) and [{8-(diphenylphosphinyl)-1,2,3,4-tetrahydronaphthyl-( C 1 , P )}tris(trimethylphosphine)cobalt] (2.082(6) Å) . The overall structure of 1 resembles that of the dimeric terphenylcobalt(I) complex [CoAr i Pr 4 ] 2 (Ar i Pr 4 = C 6 H 3 -2,6(2,6- i Pr 2 C 6 H 3 ) 2 ), in which the cobalt ions (Co–Co = 2.8033(5) Å) are σ-bonded to the ipso carbon of a central aryl ring of a terphenyl ligand with a Co–C bond length of 2.0058(16) Å and π-bonded to a flanking aryl ring of a terphenyl ligand attached to the other cobalt ion.…”

A General Metal‐Assisted Synthesis of α‐Halo Oxime Ethers from Nitronates and Nitro Compounds

“…Unfortunately, we were not able to synthesize 1a in the catalytic variant of the reaction by using 10 mol‐% of CoBr 2 as catalyst and LiBr as the source of the bromide anion (Table 1, entry 20). It is likely that the cobalt trimethylsiloxide arising from the reaction is sufficiently inert and not transformed back into CoBr 2 upon the action of LiBr {for stable complexes of Co[OSi(CH 3 ) 3 ] 2 with LiBr see ref 12b…”

Modern concepts and methods in the chemistry of polyhedral metallasiloxanes

“…37; 111 [155], 112 [156], 113 [151] [160], which are synthesized by reacting BiCl 3 with an excess of Me 3 SiONa and subsequent partial hydrolysis under mild conditions. The coordination clusters formed by Bi(OSiMe 3 ) 3 and Me 3 SiONa molecules have Bi/Na/Si atomic ratios varying from 2/4/8 to 15/3/12, depending on the ratio of the reagents employed.…”