Related Experiment Video
Updated: May 7, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Bis-(η(2)-ethyl-ene)(η(5)-inden-yl)iridium(I)
1Department of Chemistry 0212, Virginia Tech, Blacksburg, VA 24061, USA.
Abstract:
The asymmetric unit of the title compound, [Ir(C9H7)(C2H4)2], consists of two independent mol-ecules. The bonding between iridium and the five-membered ring of the indenyl ligand shows the usual asymmetry associated with the typical ring slippage responsible for the enhanced activity of indenyl metal compounds when compared with the analogous cyclo-penta-dienyl metal compound. There are three short Ir-C bonds of 2.210 (3), 2.190 (4) and 2.220 (3) Å and two long Ir-C bonds to the C atoms that are part of the fused six-membered ring of 2.349 (4) and 2.366 (3) Å for one of the independent mol-ecules [2.208 (4), 2.222 (3), 2.197 (4) Å for the short distances and 2.371 (3) and 2.358 (3) Å for the long distances in the second mol-ecule]. This results in both indenyl ligands being slightly kinked, with dihedral angles of 6.8 (4)° and 6.5 (4)°.
Related Concept Videos
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
Nomenclature of Alkynes
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...

