134882-90-9

Upstream product

• 134882-83-0 [(1,1,1-tris(diphenylphosphinomethyl)ethane)Ir(C₂H₄)(H)2]BPh₄ 
• 74-86-2 acetylene 
• 74-85-1 ethene 

Downstream Products

• 135006-00-7 (triphos)Ir(η4-benzene)(BPh4) 
• 162761-41-3 Ir(CH₃C(CH₂P(C₆H₅)2)3)(C₂H₂)⁽¹⁺⁾*B(C₆H₅)4^(1-)=[Ir(CH₃C(CH₂P(C₆H₅)2)3)(C₂H₂)][B(C₆H₅)4] 
• 162718-95-8 [(MeC(CH2PPh2)3)Ir((1-η(1):4-6-η(3))-hexatriene)]BPh4 

Relevant academic research and scientific papers

Mechanistic study of Ir(H)2-assisted transformations of ethyne: Cyclotrimerization, cooligomerization with ethene, and reductive coupling

The (ethene)dihydride complex [(triphos)Ir(H)2(C2H4)]BPh4 (1) is capable of promoting a variety of transformations of ethyne, including cyclotrimerization to benzene, cooligomerization with ethene to hexa-1,3,5-triene, reductive coupling to buta-1,3-diene, and hydrogenation to ethene (triphos = MeC(CH2PPh2)3). A detailed study under various experimental conditions, the detection of several intermediates along the various reaction paths, and the use of isolated complexes in independent reactions, taken together, permit mechanistic conclusions that account for the varied products. In particular, the cyclotrimerization and cooligomerization reactions are mediated by an iridacyclopentadiene species which is trapped by either ethyne or ethene. Consumption of the hydride ligands of 1 by C2H2 or C2H4 is an ingredient for both cyclotrimerization and cooligomerization reactions but is not necessary to accomplish the reductive dimerization of ethyne to buta-1,3-diene for which, conversely, the two hydride ligands are mandatory.

Molecular solid-state organometallic chemistry of tripodal (polyphosphine)metal complexes. Catalytic hydrogenation of ethylene at iridium

The solid-gas reactions of [(tripohs)Ir(H)2(C2H4)]BPh4 (1) with CO, C2H4, and H2 are described [triphos = MeC(CH2PPh2)3]. The gaseous reactants promote the elimination of ethane from 1 and the formation of [(triphos)Ir(CO)2]BPh4, [(triphos)Ir(C2H4)2]BPh4, and [(triphos)Ir(H)2]BPh4, respectively. The latter 16-electron species is isolable in the solid state at temperatures 2]+ dimerizes in the solid state to give the tetrahydride [(triphos)HIr(μ-H)2HIr(triphos)]2+. Dimerization is avoided when the unsaturated fragment is incorporated into the lattice of a polyoxometalate cluster such as PW12O403-. The complex [(triphos)Ir(H)2(C2H4)]BPh4 is an effective catalyst for the hydrogenation of ethylene in the solid state at 60 °C. Comparisons are made with analogous fluid solution-phase systems.

Assembling ethylene, alkyl, hydride, and CO ligands at iridium

The iridacyclopropane complex [(tripos)Ir(Cl)(C2H4)] is the starting point to synthesize a number of stable iridium complexes containing various combinations of participative ligands such as hydride, ethylene, alkyls and heteroalkyls, alkynes, and carbon monoxide: Ir(H)(C2H4), Ir(H)2(C2H4), Ir(C2H5)(C2H4), Ir(CO)2, Ir(H)(C2H5)(CO), Ir(H)2(CO), Ir(H)2(CH2CH2PEt3), Ir(H)3, Ir(H)2(C2H5), Ir(H)2(C3H7), Ir(C2H4)2, Ir(RC≡CR), IrH(μ-H)2HIr, and IrH(μ-Cl)2HIr. Due to the tripodlike structure of the ligand MeC(CH2PPh2)3 (triphos), all the complexes invariably exhibit a facial arrangement of the phosphorus and non-phosphorus ligands. The contemporaneous availability of so many related species has allowed a comparative experimental study on several important reactions. These include (i) reductive elimination of C-H and H-H bonds from dihydride alkyl complexes, (ii) reductive elimination of H-H bonds vs hydride migration in dihydride ethylene species, (iii) nucleophilic additions to coordinated double bonds, (iv) phosphine arm dissociation in triphos complexes, and β-H elimination vs C-H bond reductive elimination in hydride alkyl complexes. In most instances, such reactions are characterized by stereo- and chemoselectivity. Valuable information on the role played by the nature of the metal and of the phosphine ligands in determining the reactivity has been provided by a comparison among strictly related Rh and Ir complexes containing either triphos or three comparable monophosphines.