Overcoming the Inertness of Iridium(III) in a Facile Single‐Crystal to Single‐Crystal Reaction of Iodine Vapor with a Cyclometalated Chloride Monomer

Abstract

Iridium(III) is often considered to be one of the most inert octahedral metal ions. Herein we present a phenanthroimidazole-based bis-cyclometalated iridium(III) chloride undergoing a facile chloro ligand exchange with iodine, in a gas-solid reaction under ambient conditions. Monitoring the progress of the reaction by X-ray diffraction analysis reveals the crystal-packing-induced exceptional stereoselectivity of this topochemical transformation. The results provide excellent opportunities to modulate the geometry and kinetic properties of cyclometalated iridium(III) complexes that may be very promising in catalysis and design of anticancer agents.

Classics Meet Classics: Theoretical and Experimental Studies of Halogen Bonding in Adducts of Platinum(II) 1,5-Cyclooctadiene Halide Complexes with Diiodine, Iodoform, and 1,4-Diiodotetrafluorobenzene

“…Within the series of I 2 adducts no substitution of the halide coordinated to the Pt­(II) complex takes place, although for transition-metal complexes substitution of the halide in a reaction with I 2 is known in the literature. , One of the rare examples with no halide substitution can be found in the work of Johnson et al, where the series of sterically crowded neutral pincer palladium complex eswith various halides (Cl, Br, I) interact with an I 2 molecule. However, the most probable explanation is steric hindrance preventing the substitution, yet in the I 2 adducts obtained in the current work steric availability does not result in halide substitution.…”

Activation of a Metal‐Halogen Bond by Halogen Bonding

“…[14][15][16][17][18] Halogen bonds to halide [19][20][21][22] ligands as well as numerous other [23] Lewis basic ligands in metal complexes have been observed for inorganic and organic halogen bond donors. [24] Beyond coordination of these ligands by halogen bonding, only a handful [25][26][27][28] of instances exist, in which ligand exchange is observed. In these cases, elemental iodine or bromine were used as halide exchange reagents: even though intermediary halogen bonding was postulated, in the progress of the reaction the I À I or Br À Br bonds were cleaved.…”

A Panchromatic Cyclometalated Iridium Dye Based on 2-Thienyl-Perimidine

“…Though the vast majority of C^N-cyclometalated iridium(III) chlorides are μ-chloro-bridged dimers [ 27 ], it is well documented that the increase in the steric pressure (for example, induced by phenanthroimidazole-based cyclometalated ligands) destabilizes the iridium octahedron and rare monomeric trigonal–bipyramidal chlorides can be isolated [ 28 , 29 , 30 , 31 , 32 , 33 ]. Given that the perimidine core is sterically more bulky than nitrogen-containing parts of cyclometalated ligands commonly used in iridium(III) chemistry (in most cases, pyridine ring in 2-phenylpyridines), and is rather similar to the phenanthroimidazole unit, the formation of the above monomeric species becomes possible.…”