Synthesis and Characterization of Carbazolide-Based Iridium PNP Pincer Complexes. Mechanistic and Computational Investigation of Alkene Hydrogenation: Evidence for an Ir(III)/Ir(V)/Ir(III) Catalytic Cycle was written by Cheng, Chen;Kim, Bong Gon;Guironnet, Damien;Brookhart, Maurice;Guan, Changjian;Wang, David Y.;Krogh-Jespersen, Karsten;Goldman, Alan S.. And the article was included in Journal of the American Chemical Society in 2014.Synthetic Route of C8H16Cl2Ir2 This article mentions the following:
New carbazolide-based Ir pincer complexes (carbPNP)Ir(C2H4) (3a, carbPNPH = 1,8-bis[(diisopropylphosphino)methyl]-3,6-dimethyl-9H-carbazole) and (carbPNP)Ir(H)2 (3b) were prepared and characterized. The dihydride, 3b, reacts with ethylene to yield the cis-dihydride ethylene complex cis-(carbPNP)Ir(C2H4)(H)2. Under ethylene this complex reacts slowly at 70° to yield ethane and the ethylene complex, 3a. Kinetic anal. establishes that the reaction rate is dependent on ethylene concentration and labeling studies show reversible migratory insertion to form an Et hydride complex prior to formation of 3a. Exposure of cis-(carbPNP)Ir(C2H4)(H)2 to H results in very rapid formation of ethane and dihydride, 3b. DFT anal. suggests that ethane elimination from the Et hydride complex is assisted by ethylene through formation of (carbPNP)Ir(H)(Et)(C2H4) and by H2 through formation of (carbPNP)Ir(H)(Et)(H2). Elimination of ethane from Ir(III) complex (carbPNP)Ir(H)(Et)(H2) is calculated to proceed through an Ir(V) complex (carbPNP)Ir(H)3(Et) which reductively eliminates ethane with a very low barrier to return to the Ir(III) dihydride, 3b. Under catalytic hydrogenation conditions (C2H4/H2), cis-(carbPNP)Ir(C2H4)(H)2 is the catalyst resting state, and the catalysis proceeds via an Ir(III)/Ir(V)/Ir(III) cycle. This is in sharp contrast to isoelectronic (PCP)Ir systems in which hydrogenation proceeds through an Ir(III)/Ir(I)/Ir(III) cycle. The basis for this remarkable difference is discussed. In the experiment, the researchers used many compounds, for example, Chlorobis(ethylene)iridium(I) dimer (cas: 39722-81-1Synthetic Route of C8H16Cl2Ir2).
Chlorobis(ethylene)iridium(I) dimer (cas: 39722-81-1) belongs to organic chlorides. Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. Alkyl chlorides are versatile building blocks in organic chemistry. While alkyl bromides and iodides are more reactive, alkyl chlorides tend to be less expensive and more readily available.Synthetic Route of C8H16Cl2Ir2
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics