Preparation and Characterization of [(.eta.-indenyl)Ni(PPh3)Cl]

Abstract

The complex [fy-indenyl)Ni(PPha)Cl] has been synthesized and characterized by single-crystal X-ray structural analysis and NMR OH, 13C, 31P) spectroscopy. The energy barrier to indenyl ring rotation is ca. 16 kcal! mol.

Cationic R‐Substituted‐Indenyl Nickel(II) Complexes of Arsine and Stibine Ligands: Synthesis, Characterization, and Catalytic Behavior in the Oligomerization of Styrene

“…For complexes 2 , 9 , 10 and 11 this parameter is 0.213, 0.259, 0.242, 0.248 Å, respectively, indicating an intermediate hapticity between η 5 and η 3 . These values are comparable to those already reported for neutral [Ni(η‐Ind)(PR 3 )X][9a, b], , or cationic [Ni(η‐Ind)(L)L′] + derivatives[8a], [9a, d], [16b], The Ind ligands with η 3 or intermediate η 5 /η 3 hapticity are deviated from planarity, resulting in the reduction of the interaction between the carbon atoms C3a and C7a and the metal center. This effect can be also quantified, in the solid state, by calculating the hinge angle , HA, and the fold angle , FA.…”

Absorption spectroscopy of (Ind)Ni(PPh3)X (Ind = indenyl, 1-Me-indenyl; X = Cl, Br, Me) and M(Ind)2 (M = Ni, Ru; Ind = indenyl)

“…Therefore, the hapticity of the indenyl ligand in these compounds a pears to P lie somewhere in the continuum defined by the $, q , and the (r11,r12) coordination modes. We have suggested that this sideways slippage is caused by the different trans influences of the PPh, and C1 ligands (10). Consistent with this reasoning, replacing C1 in the Ind complexes by the higher trans influence ligand Me results in a "symmetrically slipped" indenyl ligand, i.e., Ni-C1 = Ni-C3 and Ni-C3a = Ni-C7a ( For personal use only.…”

“…1. This "sideways slippage" leads to unequal distances between the nickel atom and the carbons of the five-membered ring such that Ni-C7a (10). Therefore, the hapticity of the indenyl ligand in these compounds a pears to P lie somewhere in the continuum defined by the $, q , and the (r11,r12) coordination modes.…”

Synthesis of new donor/acceptor η5-cyclopentadienyl and η5-indenyliron(II) complexes with p-benzonitrile derivatives. Crystal structures of [Fe(η5-C5H5)(CO)(P(OC6H5)3)(p-NCC6H4NO2)][BF4]·CH2Cl2 and [Fe(η5-C9H7)(CO)(P(OC6H5)3)(p-NCC6H4NO2)][BF4]

“…The hapticity of the indenyl ligand can be evaluated spectroscopically by comparing the 13 C-NMR chemical shifts of the ring junction carbons (C3a, C7a) in the metal complex with those of the sodium indenyl: larger distortions from h 5 coordination result in larger downfield shifts [9][10][11]. According to this procedure, the parameter Dl(C-3a,7a)= l(C-3a,7a (h-indenyl complex))− l(C-3a,7a (sodium indenyl)) has been proposed as an indication of the indenyl distortion, having values in the range −20 to −40 ppm for planar h 5 -indenyl, −10 to −20 ppm for a partially slipped h 5 -indenyl and + 5 to + 30 ppm for h 3 -indenyl ligands [12].…”