Der 1-dimethylaminoethyl-2,3,4,5-tetramethylcyclopentadienyl-ligand in der Chemie von Nickel, palladium und platin; molekülstruktur von [(C5Me4CH2CH2NMe2Ni(CO)]2

Two Types of Intramolecular Lewis-Base Adducts with the [2-(Dimethylamino)ethyl]cyclopentadienyl Ligand: Synthesis and Crystal Structures of {η5:η1-C5H4[(CH2)2NMe2]}Ni−I and {η5-μ-C5H4[(CH2)2NMe2]}(Me3P)Ni−InI2,

“…An attempt to obtain a simple derivative of 2 to check the NMR spectroscopic properties of 2 somewhat further failed, however: the treatment of 2 with HBF 4 surprisingly led to complete decomposition. This finding contrasts with the behavior of [Cp* N (CO)Ni] 2 , from which compound the respective protonated derivative is reported …”

“…Compound 3 represents a new member of the series of intramolecularly complexed Cp N ligands at 3d metals. The 1 H NMR data for 3 are similar to those for other related systems such as Cp* N CoI 2 2e. The formation of 7 is proved by NMR and mass spectroscopy.…”

“…The presence of a stable intramolecular Lewis base adduct, involving the (dimethylamino)ethyl unit, is indicated in the 1 H NMR spectra by a downfield shift of the methylene protons in a position α to the terminal N atom of the side chain. , Furthermore, the multiplicity of the spin system of the CH 2 CH 2 moiety changes from a simple AB 2 system of the free side chain to a more or less resolved AA‘BB‘ system upon coordination to the Lewis acid center, because of the restricted conformational freedom. , The 1 H and 13 C NMR data for the noncoordinated ethylamino moiety of 2 are very similar to the values reported for the permethylated derivative [Cp* N (CO)Ni] 2 (Cp* N = 1-[2-dimethylamino)ethyl]-2,3,4,5-tetramethylcyclopentadienyl), the structure of which is known, proving the existence of the free uncomplexed aminoethyl group . The 1 H NMR spectrum of the two methylene groups for 2 shows some unusual temperature dependence.…”

“…The coordination chemistry of functionalized cyclopentadienyl ligands was recently enriched by the introduction of the (dimethylamino)ethyl group at the Cp ring . Jutzi et al have been studying a number of metal complexes bearing this Lewis base functionalized ligand and its tetramethyl ring-substituted derivative in detail . The benefit of such a ligand, capable of stabilizing both soft and hard metal centers by intramolecular adduct formation, was demonstrated.…”

Carbon dioxide cleavage by a Ni 2 complex supported by a binucleating bis(N-heterocyclic carbene) framework

“…An IR spectrum of 7 shows a strong band at 1825 cm −1 , consistent with the stretching vibration of a bridging CO moiety (Scheme 4). 23 When 13 CO 2 was added to 5 , a signal at 171 ppm was initially observed in the 13 C NMR spectrum (see supporting information), possibly indicating a carbon dioxide complex of nickel, while the final product mixture showed two sharp signals at 161 ppm, consistent with nickel carbonate complexes. 24 The 13 C signal corresponding to the bridging carbonyl ligands of 7 could not be observed by 13 C NMR spectroscopy even at elevated temperatures, possibly due to fluxional exchange processes of the dinickel unit about the central arene ring.…”