Tris(triphenylphosphan)nickel(0)-Komplexe mit Nitril-Liganden

Tris(triphenylphosphane)nickel(0) Complexes with Nitrile Ligands . Synthesis, properties and reaction behaviour of (Ph₃P)₃Ni(η¹-NCR) (R = PhCH₂, 2-MeC₆H₄, Me₃Si) complexes as well as the X-ray structure of (Ph₃P)₃Ni(η¹-NCSiMe₃) are described. With NC(CH₂)_nBr (n = 1, 2) instead of the analogous nitrile complexes (Ph₃P)₂NiBr₂ and CH₃CN or C₂H₅CN respectively are formed.     

Crystal Structure of Tris(2,2'-bipyridine)nickel(II) Tetrachlorozincate

1　INTRODUCTIONThe coordination chemistry oftransition metalcomplexeshasbecomeofremark able interestin recentyears.Sotoftetal.reported the structure of Ni( CH3CN) 6·Zn Cl4 〔1〕.Recently,Shyu etal.reported the structure of〔 Ni( bipy) 3〕〔 Fe( CN) 5 ( NO)〕· 3 H2 O〔2〕.Herein we reportthe structure oftitle complex〔 Ni( bipy) 3〕〔 Zn Cl4 〕 which issimilarto theformertwo complexes.Itisvery interesting to synthesizebimetallic compoundsfor both theoreticalstudy and practicalapp…     

Tris(tri‐o‐tolyl phosphite‐κP)nickel: a coordinatively unsaturated nickel(0) complex

A previously reported complex, [Ni(C₂₁H₂₁O₃P)₃] or Ni[P(O‐o‐tolyl₃)₃] [Gosser & Tolman (1970). Inorg. Chem. 9 , 2350–2353], crystallized in the monoclinic space group C2/c, and its solid‐state structure was determined. The Ni⁰ atom adopts an essentially trigonal‐planar geometry as a consequence of the steric congestion of the ligands. Three of the phenoxy rings on two phosphite ligands were modelled as being disordered over two sets of sites, and the occupancy factors were set at 0.5 after trial refinement and intramolecular contact considerations. The exact ligand cone angle has been calculated to be 163.6°.     

Reactions of Aluminium Tribromide with Tetrakis(triphenylphosphine)nickel(0) and Tetrakis(triethylphosphite)nickel(0) Complexes

Reactions of aluminium tribromide with the Ni(0) phosphine and phosphite complexes are studied by EPR method. AlBr₃was found to cause the oxidation of the transition metal in the (PPh₃)₄Ni complex to the univalent state with the formation of the tetracoordinated (PPh₃)₃NiBr complex. With an excess of AlBr₃, the phosphine ligands are eliminated from the coordination sphere of Ni(I), and the coordinatively unsaturated complexes are destroyed to give the colloidal nickel. In the reaction of (P(OEt)₃)₄Ni with AlBr₃, Ni(0) is also oxidized to Ni(I), but the acido ligand is not eliminated even with a 15-fold excess of the Lewis acid. The activity of catalytic systems on the basis of the Ni(0) phosphine complexes and the Lewis acids in the low-molecular oligomerization reactions of olefines is determined by the cationic coordinatively unsaturated Ni(I) complexes formed in these systems.