Cationic η3-Triphenylcyclopropenylnickel complexes with tridentate ligands containing N,P, As as the donor atoms. Molecular structure of η3-triphenylcyclopropenyl-1,1,1-tris(diphenylphosphinomethyl)ethanenickel perchlorate

The [(C₃Ph₃)Ni(PPh₃)₂]ClO₄ complex reacts with the tridentate ligands, 1,1,1-tris(dimethylphosphinomethyl)ethane, 1,1,1-tris(diphenylphosphinomethyl)ethane, (bis(2-diphenylphosphino)ethyl)phenylphosphine, (bis(2-diphenylphosphino)ethyl)-n-propylamine, and 1,1,1-tris(diphenylarsinomethyl)ethane to give cationic η³-triphenylcyclopropenyl complexes of formula [(C₃Ph₃)NiL]Y (Y = ClO₄, BPh₄). An uncharged derivative with the formula [(C₃Ph₃)Ni(hb(3,5-me₂Pz)₃)] (hb(3,5-me₂Pz)₃ = hydrotris(3,5-dimethyl-1-pyrazolyl)borate) has also been prepared. The molecular structure of [(C₃Ph₃)Ni(triphos)]ClO₄ has been determined from counter diffraction data. The crystals are monoclinic, space group P2₁/n with cell dimensions: a 17.750(5), b 17.629(5), c 16.509(4) Å; β 92-59(9)°, D_c = 1.359 g cm^?3 for Z = 4. Full matrix least-squares refinement led to the conventional R factor of 0.064 for 2556 observed reflections. The molecular structure consists of [(C₃Ph₃)Ni(triphos)]⁺ cations and ClO₄^? anions. The nickel atom is coordinated to the three phosphorus atoms of the triphos ligand, and to the C₃Ph₃ fragment in a symmetric η³ fashion.