ERIC Number: EJ823769
Record Type: Journal
Publication Date: 2008-Dec
Pages: 3
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: N/A
Preparation of a N-Heterocyclic Carbene Nickel(II) Complex: Synthetic Experiments in Current Organic and Organometallic Chemistry
Ritleng, Vincent; Brenner, Eric; Chetcuti, Michael J.
Journal of Chemical Education, v85 n12 p1646-1648 Dec 2008
A four-part experiment that leads to the synthesis of a cyclopentadienyl chloro-nickel(II) complex bearing a N-heterocyclic carbene (NHC) ligand is presented. In the first part, the preparation of 1,3-bis-(2,4,6-trimethylphenyl)imidazolium chloride (IMes[middle dot]HCl) in a one-pot procedure by reaction of 2,4,6-trimethylaniline with paraformaldehyde, glyoxal, and hydrochloric acid is described. The reaction of NiCl[subscript 2][middle dot]6H[subscript 2]O with aqueous ammonia to give [Ni(NH[subscript 3])[subscript 6]]Cl[subscript 2], and the reaction of sodium in neat dicyclopentadiene at 160 [degrees]C to produce sodium cyclopentadienide in a one-pot synthesis are both delineated in the second part of this experiment. The reaction of [Ni[Ni(NH[subscript 3])[subscript 6]]Cl[subscript 2], with NaCp to yield [Ni([eta][superscript 5]-C[subscript 5]H[subscript 5][subscript 2]] forms the third part. Finally, the procedure ends with the reaction of nickelocene with IMes[middle dot]HCl to afford the nickel(II) half-sandwich complex [Ni([eta][superscript 5]-C[subscript 5]H[subscript 5])(IMes)Cl]. This sequence of experiments provides an excellent example of NHC-ligand preparation and its subsequent complexation to a transition metal and is appropriate for an advanced undergraduate or a graduate lab course. It also provides an opportunity for students to learn standard Schlenk techniques. Furthermore, the characterization of some of the products by [to the first power]H NMR spectroscopy demonstrates the utility of [to the first power]H NMR in both organic and organometallic chemistry. (Contains 4 schemes.)
Descriptors: Organic Chemistry, Science Instruction, Science Experiments, Spectroscopy, College Science, Water, Molecular Structure, Teaching Methods, Undergraduate Study
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Publication Type: Journal Articles; Reports - Research
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A