340004-36-6Relevant academic research and scientific papers
Structural characterisation of cationic methylallyl, methylindenyl and pentamethylcyclopentadienyl nickel complexes containing the bulky phosphine 1,2-bis(diisopropylphosphino)ethane
Tenorio, Manuel Jimenez,Puerta, M. Carmen,Salcedo, Isabel,Valegra, Pedro
, (2008/10/08)
A novel high-yield, convenient synthetic method for the complex [Ni(COD)2] has been developed based upon the use of dibutylmagnesium as reducing agent. The cationic complexes [Ni(η3CH2C(R)CH2)(dippe)][BPh4] (R = Me la or H 1b; dippe = Pr2iPCH2CH2PPr2i ) were obtained by reaction of [Ni(COD)2] with BrCH2C(R)=CH2 in diethyl ether, followed by treatment with dippe and NaBPh4 in methanol. [Ni(2-MeInd)(dippe)][BPh4] 2 (2-MeInd = 2-methylindenyl) and [Ni(C5Me5)(dippe)][BPh4] 3 were respectively prepared by reaction of either [Ni(2-MeInd)Br(PPh3] or [Ni(C5Me5)Br(PPh3)] with dippe and NaBPh4 in methanol. The crystal structures of 1a, 2 and 3 were determined. All of the compounds show pseudo-square planar two legged piano stool structures. The methylallyl ligand in la shows η3 coordination as expected, whereas in 2 the occurrence of an allyl-ene distortion in the 2-methylindenyl ligand leads to an intermediate η3η5 coordination mode. An intermediate allyl-ene/diene distortion is present in the C5Me5 ligand in 3, although in this case a symmetrical η5 coordination is observed. All compounds were also characterised in solution by NMR spectroscopy.
