12257-42-0Relevant articles and documents
Complexes with heterocyclic nitrogen ligands - III. Cationic rhodium(I) derivatives and applications in catalysis
Moya, Sergio A.,Pastene, Ruben,Sariego, Renato,Sartori, Rebeca,Aguirre, Pedro,Le Bozec, Hubert
, p. 1823 - 1827 (1996)
The preparation and spectroscopic properties of mononuclear cationic complexes of rhodium(I) coordinated to the diolefin 2,5-norbornadiene (NBD) and to the heterocyclic nitrogen ligands 6,7-dihydrodipyrido-[2,3-b: 3′,2′-j]-1,10-phenanthroline (2-4N), 7,8-dihydro-6H-cyclohepta-[2,1-b: 3,4-b]-di-1,8-naphthyridine (3-4N) and 2,2′-bi-(3-methyl)-1,8-naphthyridine (Me-4N) are described. The complexes show the characteristic intraligand bands of the ligands and an electronic low energy band insensitive to solvent changes and of low intensity, which may be assigned to a ligand field band. The NMR properties agreed with the IR results showing the equivalence of the two naphthyridine fragments in the complexes. Electrochemically all the complexes display two reductions and one oxidation waves, in the potential region from +1.5 to -2.4 V vs Fc+/Fc. The water gas shift reaction (WGSR) and the selective reduction of nitrobenzene to aniline under WGSR conditions are effectively catalysed by these complexes.
Preparation and properties of inclusion compounds of transition-metal complexes of cycloocta-1,5-diene and norbornadiene with cyclodextrins
Harada, Akira,Yamamoto, Shyoko,Takahashi, Shigetoshi
, p. 2560 - 2563 (2008/10/08)
Inclusion compounds of rhodium and platinum complexes of cycloocta-1,5-diene (COD) and norbornadiene (NBD) with cyclodextrins were prepared. Two-to-one (cyclodextrin to guest) inclusion compounds were obtained in high yields in a crystalline state by the treatment of β-cyclodextrin (β-CD) with bis(μ-halo)bis(η4-cycloocta-1,5-diene)dirhodium, [Rh(μ-X)(COD)]2 (X = Cl, Br, I), and bis(μ-chloro)bis(η4-norbornadiene)dirhodium, [Rh(μ-Cl)(NBD)]2. The formation of inclusion compounds is selective. One-to-one inclusion compounds were obtained by the reaction of β-CD with (cycloocta-1,5-diene)platinum dihalides, Pt(COD)X2 (X = Cl, Br, I), in high yields, while γ-CD formed 1:1 inclusion compounds with Pt(COD)I2 but not with Pt(COD)Cl2. α-Cyclodextrin did not form inclusion compounds with any transition-metal complexes of cyclooctadiene and norbornadiene. The inclusion compounds are thermally stable and do not liberate the guest when heated to 200°C in vacuo at which temperature the nonincluded guest [Rh(μ-Cl)(COD)]2 already decomposed. The inclusion compounds were characterized by 1H NMR, IR, UV, and circular dichroism spectra. A large induced Cotton effect was observed with β-CD-[Rh(μ-Cl)(COD)]2. The 1H NMR spectrum of [Rh(μ-Cl)(COD)]2 in the presence of β-CD shows two sets of resonances for two different CD species that are assigned to free β-CD and the complexed β-CD, respectively. The binding mode will be discussed.
Application of microwave dielectric loss heating effects for the rapid and convenient synthesis of organometallic compounds
Baghurst, David R.,Mingos, D. Michael P.,Watson, Michael J.
, p. C43 - C45 (2007/10/02)
Diolefin-rhodium(I) and -iridium(I) complexes have been synthesised in a sealed Teflon container by use of microwave heating.The products are obtained in excellent yields and in less than 1 minute compared with many hours by conventional reflux techniques
Synthesis and reactivity of formamidinato rhodium(I) complexes
Piraino, Pasquale,Tresoldi, Giuseppe,Faraone, Felice
, p. 305 - 312 (2007/10/02)
The syntheses of [Rh(diol)(formamidine)]2 complexes (diol cycloocta-1,5-diene (1); diol norbornadiene (2); formamidine N,N′-di-p-tolylformamidine) are reported. These complexes are dimeric and contain the bridging formamidino ligand. They react with CO, dppe and PPh3 with displacement of the diene ligand to yield the known [Rh(CO)2(formamidine)]2, [Rh(dppe)2]+ and [Rh(PPh3)2(formamidine)], respectively; the last complex, in which the formamidine acts as a chelating ligand, was isolated only as the O2 adduct. With HCl or HBF4 aqueous 1 and 2 do not form hydrides but instead the formamidino cation [p-tolyl-NHCHNHtolyl-p]+ and the complexes [Rh(diol)X]2 (X Cl, F); a possible scheme for the reaction with HCl is proposed. The [Rh(C8H12)(formamidine)]2 complex reacts with heterocumulenes as CS2, SO2, PhNCS and PhNCO with diene displacement; the only product isolated was [Rh(CS2)2(formamidine], to which a polymeric structure is assigned.
A vibrational study of the metal-olefin bond in norbornadiene complexes of Rh(I), Pd(II) and Pt(II)
Wertz, D. W.,Moseley, M. A.
, p. 467 - 472 (2007/10/02)
Vibrational assignments of the complexes 2, PtCl2C7H8, and PdCl2C7H8 have been undertaken.A reinvestigation of the norbornadiene spectrum was necessary and a new set of assignments is given.The shift in energy of bands I and II and the out-of-plane olefinic C-H wagging modes, as well as the relative energies of the bands associated with the metal-olefin motions are consistent with the total metal-norbornadiene interaction following the order Rh > Pt > Pd and the excent of the ? component being ordered as Rh ca/= Pt > Pd.
