33409-86-8Relevant academic research and scientific papers
Iridium complexes of aromatic N,O and N,N chelating ligands. Structures of [Ir(8OQ)(cod)], [Ir(8OQd)(cod)], [Ir2(7AI)2(cod) 2] and [Ir(8OQd)(H)(EPh3)(cod)] (8OQ = 8-oxyquinolinate, 8OQd = 2-methyl-8-oxyquinolina
Rampersadh, Terisha,Fernandes, Manuel A.,Carlton, Laurence
, p. 151 - 160 (2014)
The X-ray structures of the complexes [Ir(8OQ)(1,5-cod)] (1), [Ir(8OQd)(1,5-cod)] (2) and [Ir2(μ-7AI)2(1,5-cod) 2] (3) (where 8OQ, 8OQd and 7AI are anions derived from 8-hydroxyquinoline, 2-methyl-8-hydroxyquinoline (8-hyd
Rhodium-mediated stereoselective polymerization of "carbenes"
Hetterscheid, Dennis G. H.,Hendriksen, Coen,Dzik, Wojciech I.,Smits, Jan M. M.,Van Eck, Ernst R. H.,Rowan, Alan E.,Busico, Vincenzo,Vacatello, Michele,Van Axel Castelli, Valeria,Segre, Annalaura,Jellema, Erica,Bloemberg, Tom G.,De Bruin, Bas
, p. 9746 - 9752 (2007/10/03)
Unprecedented rhodium-catalyzed stereoselective polymerization of "carbenes" from ethyl diazoacetate (EDA) to give high molecular mass poly(ethyl 2-ylidene-acetate) is described. The mononuclear, neutral [(N,O-ligand)M1(cod)] (M = Rh, Ir) catalytic precursors for this reaction are characterized by (among others) single-crystal X-ray diffraction. These species mediate formation of a new type of polymers from EDA: carbon-chain polymers functionalized with a polar substituent at each carbon of the polymer backbone. The polymers are obtained as white powders with surprisingly sharp NMR resonances. Solution and solid state NMR data for these new polymers reveal a highly stereoregular polymer, with a high degree of crystallinity. The polymer is likely syndiotactic. Material properties are very different from those of atactic poly(diethyl fumarate) polymer obtained by radical polymerization of diethyl fumarate. Other diazoacetates are also polymerized. Further studies are underway to reveal possible applications of these new materials.
Synthesis and X-ray structural characterization of binuclear iridium(I) and rhodium(I) hydroxypyridinate complexes. 1. Complete assignment of the 1H NMR spectra by two-dimensional and NOE techniques. The nature of inside and outside 1H chemical shift differences
Rodman, Gary S.,Mann, Kent R.
, p. 3338 - 3346 (2008/10/08)
Six new d8-d8 complexes, [Ir(COD)(μ-hp)]2, [Ir(COD)(μ-mhp)]2, [Ir(COD)(μ-chp)]2, [Ir(COD)(μ-2hq)]2, [Rh(COD)(μ-hp)]2, and [Rh(COD)(μ-mhp)]2 (hp = 2-hydroxypyridinate, mhp = 6-methyl-2-hydroxypyridinate, chp = 6-chloro-2-hydroxypyridinate, 2hq = 2-hydroxyquinolate, COD = 1,5-cyclooctadiene), were synthesized and characterized by 1H NMR, 13C NMR, and IR spectroscopy and FAB mass spectrometry. Other than our preliminary communication, these are the first rhodium(I) and iridium(I) hydroxypyridinate complexes reported to date. X-ray crystallographic analyses of the isostructural [M(COD)(μ-mhp)]2 (M = Ir and Rh) complexes confirmed the binuclear nature of the complexes. Both [M(COD)μ-mhp)]2 complexes crystallize in the P21/c space group with Z = 4. For M = Rh, V = 2544 (4) A?3, a = 14.963 (8) A?, b = 12.038 (2) A?, c = 14.673 (10) A?, and β = 105.75 (4)°. Full-matrix least-squares refinement (307 variables, 4006 reflections) converged to give R and Rw values of 0.028 and 0.036, respectively. For M = Ir, V = 2521 (4) A?3, a = 14.847 (5) A?, b = 11.991 (2) A?, c = 14.661 (11) A?, and β = 104.99 (4)°. Full-matrix least-squares refinement (307 variables, 3335 reflections) converged to give R and Rw values of 0.030 and 0.031, respectively. The complexes have a nonpolar structure with head-to-tail bridging ligands that persists in solution and the gas phase. The M-M separations (Rh-Rh, 3.367 (1) A?; Ir-Ir, 3.242 (2) A?) indicate significant metal-metal interactions are present in both complexes. A twist angle (27° and 25° for M = Ir and Rh, respectively) in the flexible eight-membered (MNCO)2 framework, not present in the six-membered ring of the analogous [M(COD)(μ-pz)]2 (pz = pyrazolate) complexes, relieves steric strain between the two bulky COD ligands. The open book geometry and asymmetry of the bridging ligands attributes the molecules low-point symmetry, leading to complex NMR spectra. The complete assignment of the 1H NMR spectrum of [Ir(COD)(μ-hp)]2 (and by analogy, the spectra of the other five complexes) was carried out with selective decoupling, NOE, and two-dimensional NMR techniques. The NOE observed between hp proton H5 and COD proton H15 allowed the precise assignment of all 12 COD resonances. Olefinic proton H12 (trans to N and outside ) resonates downfield of olefinic proton H11 (trans to N and inside ). Olefinic proton H15 (trans to O and outside ) resonates upfield of olefinic proton H16 (trans to O and inside). The endo methylene protons resonate upfield of the exo methylene protons. The inside / outside chemical shift differences observed for these compounds are ascribed to steric and magnetic anisotropy effects.
