Synthesis and characterization of carbonyl thiolato [Et4N][M(CO)5SR] and [Et4N]2[M2(CO)8(SR)2] complexes (M = chromium, molybdenum, tungsten). Ligand substitution reactions and x-ray crystal structure of [Et4N]2[W2(CO)8(SPh)2]

1988 ◽  
Vol 27 (20) ◽  
pp. 3636-3643 ◽  
Author(s):  
Donald J. Darensbourg ◽  
Kathryn M. Sanchez ◽  
Joe Reibenspies
Keyword(s):  
Crystal Structure ◽  
Ligand Substitution ◽  
Synthesis And Characterization ◽  
Substitution Reactions ◽  
X Ray ◽  
Ligand Substitution Reactions

scholarly journals Synthesis, Characterization and Reactivity of Chromium(VI) Alkylidenes

2019 ◽  
Author(s):  
Pengcheng Wu ◽  
Glenn P. A. Yap ◽  
Klaus Theopold
Keyword(s):  
Ligand Substitution ◽  
X Ray Diffraction ◽  
Substitution Reactions ◽  
X Ray ◽  
Chromium Vi ◽  
Organic Products ◽  
Ligand Substitution Reactions

Chromium(VI) dialkyls are remarkably acidic, yielding a new set of anionic chromium alkylidenes upon deprotonation with KN(TMS)<sub>2</sub>. We describe the characterization of three anionic chromium alkylidenes of the type [(ArN)<sub>2</sub>Cr(=CHR)(CH<sub>2</sub>R]<sup>-</sup> (R = <i><sup>t</sup></i>Bu, SiMe<sub>3</sub>, Ph; Ar = 2,6-diisopropylphenyl). NEt<sub>4</sub>[(ArN)<sub>2</sub>Cr(=CHSiMe<sub>3</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)] has been structurally characterized by X-ray diffraction. We have also studied the C-H activation of cyclohexane effected by the transient neopentylidene (ArN)<sub>2</sub>Cr(=CHCMe<sub>3</sub>). This reaction generated a tri-nuclear chromium(IV) complex, namely ‘[Cr(NAr)<sub>2</sub>]<sub>3</sub>’, as well as the two organic products cyclohexene and neopentane. A probable intermediate in this reaction could be trapped by PPh<sub>3</sub> to form (ArN)<sub>2</sub>Cr(PPh<sub>3</sub>)<sub>2</sub>. The latter undergoes ligand substitution reactions with ethylene and CO to produce p-acid complexes of tetravalent chromium.

scholarly journals Synthesis, Characterization and Reactivity of Chromium(VI) Alkylidenes

2019 ◽  
Author(s):  
Pengcheng Wu ◽  
Glenn P. A. Yap ◽  
Klaus Theopold
Keyword(s):  
Ligand Substitution ◽  
X Ray Diffraction ◽  
Substitution Reactions ◽  
X Ray ◽  
Chromium Vi ◽  
Organic Products ◽  
Ligand Substitution Reactions

Chromium(VI) dialkyls are remarkably acidic, yielding a new set of anionic chromium alkylidenes upon deprotonation with KN(TMS)<sub>2</sub>. We describe the characterization of three anionic chromium alkylidenes of the type [(ArN)<sub>2</sub>Cr(=CHR)(CH<sub>2</sub>R]<sup>-</sup> (R = <i><sup>t</sup></i>Bu, SiMe<sub>3</sub>, Ph; Ar = 2,6-diisopropylphenyl). NEt<sub>4</sub>[(ArN)<sub>2</sub>Cr(=CHSiMe<sub>3</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)] has been structurally characterized by X-ray diffraction. We have also studied the C-H activation of cyclohexane effected by the transient neopentylidene (ArN)<sub>2</sub>Cr(=CHCMe<sub>3</sub>). This reaction generated a tri-nuclear chromium(IV) complex, namely ‘[Cr(NAr)<sub>2</sub>]<sub>3</sub>’, as well as the two organic products cyclohexene and neopentane. A probable intermediate in this reaction could be trapped by PPh<sub>3</sub> to form (ArN)<sub>2</sub>Cr(PPh<sub>3</sub>)<sub>2</sub>. The latter undergoes ligand substitution reactions with ethylene and CO to produce p-acid complexes of tetravalent chromium.

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