A germanium(II) aminopyridinato compound has been synthesized and characterized by 1H and 13C NMR spectroscopy, elemental analysis and X-ray diffraction. It was easily obtained in high yield through a salt-elimination reaction by mixing the corresponding lithium salt and the GeCl2-dioxane adduct. Thermal properties, including stability, volatility, transport behavior and vapor pressure, were evaluated by thermogravimetric analysis (TGA) to confirm that it is suitable for the CVD procedure. Deposition was accomplished in a hot-wall CVD reactor system, which verified its ability as a CVD precursor for the fabrication of germanium containing films.A germanium(II) aminopyridinato compound has been synthesized and characterized by 1H and 13C NMR spectroscopy, elemental analysis and X-ray diffraction. Thermal properties, including stability, volatility, transport behavior and vapor pressure, were evaluated by thermogravimetric analysis (TGA) to confirm that it is suitable for the CVD procedure. Deposition was accomplished in a hot-wall CVD reactor system, which verified its ability as a CVD precursor for the fabrication of germanium containing films.Download high-res image (112KB)Download full-size image

•Convenient synthesis of 8-aminoquinolines from fluoroquinolines.•Selective C–F bond activation by heterocycle directing effect and Li/F interaction.•Good function group flexibility for coupling arylamines.•Steric effect has an impact on the reaction yield.An efficient and general selective method for the synthesis of 8-aminoquinoline derivatives has been disclosed through transition metal direct C–N coupling from fluoroquinolines and arylamines. Significantly, good chemo- and regio-selectivity was observed for polyfluoroquinolines in which only C–F bond on 8-substituted position was broken. Thus, this methodology proves its value as an inexpensive and efficient synthetic way to access quinolin-8amine derivatives in moderate to good yields.An efficient and general selective method for the synthesis of 8-aminoquinoline derivatives has been disclosed through transition metal direct C–N coupling from fluoroquinolines and arylamines. Significantly, good chemo- and regio-selectivity were observed for polyfluoroquinolines in which only C–F bond on 8-substituted position was broken. Thus, this methodology proves its value as an inexpensive and efficient synthetic way to access quinolin-8amine derivatives in moderate to good yields.Download high-res image (76KB)Download full-size image

Two ionic (1a and 1b) and two neutral (2a and 2b) Cu(I) complexes containing an un-deprotonated or a deprotonated nitrogen ligand {2-(4-methyl phenyl) imidazole[4,5-f]-1,10-phenanthroline, MHPIP} and different phosphine ligands (bis[2-(diphenylphosphino) phenyl]ether and PPh3) have been synthesized and characterized by elemental analysis, 1H NMR spectroscopy and X-ray crystallography (1b, 2a and 2b). The complexes adopt a distorted tetrahedral geometry constructed by MHPIP (or MPIP−) and phosphine ligands. The emission spectra show that the ionic complexes exhibit almost ignorable luminescence. However, the deprotonation of the nitrogen ligand makes the neutral complexes exhibit orange or yellow emission both in solution and solid-powder states. Considering the different luminous characters of the neutral complexes, density functional theory (DFT) calculations have been performed at the B3LYP/6-31G** level to provide information about the impact of phosphine ligands on the frontier orbital.

A family of 1,1,1,2,2,2-hexaamino-disilanes with the formula (RHN)3Si-Si(NHR)3 (R = nPr, iPr, nBu, iBu, sBu, Cy) as precursors for the CVD growth of silicon-based films has been synthesized and characterized by 1H NMR, 13C NMR, 29Si NMR, EI-HRMS, elemental analysis and X-ray diffraction where necessary. Thermal properties, including stability, volatility, transport behavior and vapor pressure were evaluated by thermogravimetric analysis (TGA) to verify that thermal properties of the precursors can be tuned by small variation of the substituents form secondary amino to primary amino units and to confirm their suitability for the CVD procedure. Finally, deposition was accomplished in a hot wall CVD reactor, which preliminarily verified the ability of these compounds as CVD precursors.A family of 1,1,1,2,2,2-hexaamino-disilanes with the formula (RHN)3Si-Si(NHR)3 (R = alkyl) as precursors for the CVD growth of silicon-based films has been synthesized and characterized. Thermal properties, including stability, volatility, transport behavior and vapor pressure were evaluated by thermogravimetric analysis (TGA) to verify that thermal properties of the precursors can be tuned by small variation of the substituents form secondary amino to primary amino units and to confirm their suitability for the CVD procedure.

The title compounds of the type (Me3Si)2N–C(N′R)(–N′′RSiMe3) (with R = iPr or Cy) as potential CVD precursors have been synthesized and characterized by X-ray diffraction, 1H NMR, 13C NMR, 29Si NMR and elemental analysis where necessary. Among these characterizations, solid-/liquid-state 29Si NMR were accomplished to study their behavior in the solid and solution. Thermal properties including stability, volatility, transport behavior and vapour pressure were evaluated by thermogravimetric analysis (TGA) to confirm that they are suitable for the CVD procedure. Deposition was accomplished in a hot wall CVD reactor system, which preliminarily verified the ability of these compounds as CVD precursors.

A family of silicon(IV) compounds, where the Si centers of trimethylsilyl (–SiMe3) are linked with 2-alkyl-aminopyridine ligands, has been synthesized by reaction of the corresponding lithium salt of these ligands and SiMe3Cl in a general procedure. They were characterized by 1H NMR, 13C NMR, 29Si NMR, EI-MS and elemental analysis where necessary. Thereinto, 29Si NMR and the synthesis of 2-N,N-bis(trimethylsilyl)aminopyridine were achieved for the confirmation of their coordination structures. Significantly, the evaluation of these silicon compounds containing 2-aminopyridinates as CVD precursors was discussed for the first time. Thermal stability, transport behavior and vapour pressures were assessed by simultaneous thermal analyses (STA). Chemical vapor deposition was accomplished in a hot wall CVD reactor system to qualitatively demonstrate the ability of them as CVD precursors.

•Aminogermylenes•Good volatilization•Aminogermylenes were investigated by TG experiments.•Ge thin film was determined and characterized.Compared to the difficult volatilization for germanium (IV) precursors, germanium (II) precursors usually have better volatilization but difficult to synthesize. A series of diamine germanium (II) precursors were synthesized, characterized and investigated by DFT calculations. These germanium (II) precursors were tested by TG experiments and showed excellent volatilization, which were suitable as a potential membrane material. Moreover, the Ge film was deposited on Si wafer directly and characterized by SEM.The diamine germanium (II) precursors were synthesized, characterized and investigated by DFT calculations. These germanium (II) precursors were tested by TG experiments and showed excellent volatilization, which were suitable as a potential membrane material. Moreover, the Ge film was deposited on Si wafer directly and characterized by SEM.

•Ir-catalyzed direct C–S formation of disulfides with fluorides is firstly reported.•An effective, convenient method to synthesize mono- and diarylthioether is given.•The C–F activation and C–S coupling were realized by one-step reaction.Carbon–fluorine bond is the strongest known single bond to carbon and proved very difficult to cleave. An iridium and phosphine promoted C–F bond activation was developed, for the first time achieving the C–S cross-coupling reaction of disulfides with aryl fluorides using iridium complex. The corresponding monoarylthiolation products were obtained at moderate to good yields. Thus, it represents a new method for the synthesis of aryl sulfides through C–F bond activation.Carbon–fluorine bond is the strongest known single bond to carbon and proved very difficult to cleave. An iridium and phosphine promoted C–F bond activation was developed, for the first time achieving the C–S cross-coupling reaction of disulfides with aryl fluorides using iridium complex. The corresponding monoarylthiolation products were obtained at moderate to good yields. Thus, it represents a new method for the synthesis of aryl sulfides through C–F bond activation.

Several new bisbenzoxazolyl iridium(III) complexes have been synthesized and characterized through X-ray crystallography. These complexes exhibit excellent catalytic activity in C–C and C–N bond formation reactions from the alkylation of amine with amine, amine with alcohol, ketone with alcohol, and alcohol with alcohol through a borrowing hydrogen reaction. Moreover, these iridium(III) complexes are effective catalysts for the alkylation of amine with alcohol and ketone with alcohol under solvent-free conditions. The catalytic activity of these complexes is greatly enhanced by noncoordinating, while the experiments have excluded the possibility of a “silver effect” (bimetallic catalysis or silver-assisted metal catalysis) from the experiments.Keywords: C−C coupling; C−N coupling; iridium complex; noncoordinating anion; solvent-free

β-Diketiminato cyclopentadienyl and ferrocenylethynyl germylenes LGeR (L = HC[C(Me)N-2,6-iPr2C6H3]2, R = Cp (1) and CCFc (2)) were prepared and utilized to synthesize the GeTe bond species. Reactions of 1, 2, and LGeCCPh (3) with an excess of Te powder proceeded in toluene under reflux successfully yielded germanetellurone L(R)GeTe (R = Cp (4), CCFc (5), and CCPh (6)). Further reaction of 4 with GeCl2·dioxane at −78 °C resulted in L(Cp)GeTe(GeCl2) (7), the first example of a germylene germanetellurone adduct. Both compounds 4 and 7 contain two isomers that are generated by the simultaneous 1,2-H- and 1,3-H-shifts over the Cp ring at the Ge atom. The reactions of L(Me)GeE with AuC6F5·SC4H8 at room temperature led to pentafluorophenyl gold(I) germanethione and germaneselone compounds L(Me)GeE(AuC6F5) (E = S (8) and Se (9)). The formation of compounds 7–9 exhibits a rare nucleophilic coordination reaction pathway by the GeE (E = S, Se, Te) bond towards the metal-containing Lewis acidic species. The structures of compounds 1, 2, and 4–9 are studied by the NMR and/or IR spectroscopy and X-ray crystallography.

A highly efficient C–C bond formation has been developed through the cross-coupling of primary and secondary alcohols. The corresponding functionalized ketones were obtained with an iridium–CNP complex as a catalyst through the borrowing hydrogen strategy. The present methodology provides an easy alternative method to aldol reaction derivatives. More importantly, the complexes were also effective catalysts for the alkylation of an aromatic amine with a tertiary alkyl amine.

•C–S coupling of thioalcohols and diaryliodonium salts.•The reaction produced high yields at room temperature.•Ligand-free and metal-free method.An efficient, general, and highly selective method for the synthesis of aryl sulfides has been developed through metal-free, direct C–S coupling from thioalcohols and diaryliodonium salts. Significantly, the reaction took only 10 min to complete and produced high yields at room temperature. Thus, this methodology proves its value as a versatile synthetic choice for a broad range of aryl sulfides, producing good to excellent yields.An efficient, general, and highly selective method for the synthesis of aryl sulfides has been developed through metal-free, direct C–S coupling from thioalcohols and diaryliodonium salts. Significantly, the reaction took only 10 min complete and produced high yields at room temperature. Thus this methodology proves its value as a versatile synthetic choice for a broad range of aryl sulfides, producing good to excellent yields.

•Pd-catalyzed direct C-sulfone formation.•CS coupling of quinones with arylsulfonyl chloride.•A convenient method for the synthesis of arylsulfonyl-quinones.•The C-sulfone coupling was realized by one-step reaction.The Pd-catalyzed direct C-sulfone formation by CS coupling of quinones with arylsulfonyl chloride has been developed. This methodology provides an effective, convenient method for the synthesis of arylsulfonyl-quinones and arylsulfonyl-1,4-diols, which are potent inhibitors of FabH.The Pd-catalyzed direct C-sulfone formation by CS coupling of quinones with arylsulfonyl chloride has been developed. This methodology provides an effective, convenient method for the synthesis of arylsulfonyl-quinones and arylsulfonyl-1,4-diols, which are potent inhibitors of FabH.

•Phosphine iridium(III) bisbenzothienyl compounds•Phosphine Ir compounds gave the typical green emission.•Ir complexes were investigated by TG experiments.•Ir complexes showed some catalytic reactivity.Phosphine-assisted bisbenzothienyl iridium(III) compounds were synthesized and characterized, and their structures were confirmed through x-ray crystallography. The TG experiment showed that bisbenzothienyl iridium(III) compounds have excellent stability. In terms of photophysical properties, these complexes have the typical green emission.Phosphine-assisted bisbenzothienyl iridium(III) compounds were synthesized and characterized, and their structures were confirmed through X-ray crystallography. The TG experiment showed that bisbenzothienyl iridium(III) compounds have excellent stability. In terms of photophysical properties, these complexes have the typical green emission. At the same time, these complexes were feasible for the transfer dehydrogenation reaction with moderate yield.

A novel ligand-free, transition metal-free direct C–H functionalization of quinones with diaryliodonium salts has been developed for the first time. The transformation was promoted only through the use of a base and gave aryl quinone derivatives in moderate to good yields. This methodology provided an effective and easy way to synthesize β-secretase inhibitors. The radical trapping experiments showed that this progress was the radical mechanism.

In this paper, a C–F bond activation reaction of a chloro-bridged iridium(III) dimer (dfppy)2Ir(μ-Cl)2Ir(dfppy)2 (1) (dfppy denotes 2-(4,6-difluorophenyl)pyridyl) in the presence of sodium methoxide has been reported, leading to the formation of a heteroleptic cyclometalated iridium(III) fluorophenylpyridine complex 2. HPLC-mass analysis confirmed the release of formaldehyde in the product mixture. When sodium benzyloxide was used as the base, complex 2 was also generated with the release of a benzaldehyde derivative. Complex 2 has been fully characterized by 1H-NMR, 19F-NMR and X-ray crystallographic methods, confirming the partial loss of one of the fluorine atoms on one of the cyclometalated phenylpyridyl ligands. Photophysical studies of complex 2 show that it has a similar absorption spectrum to that of Ir(III)(dfppy)3. However, the emission spectrum shows a red shift maximum emission band at 478 nm due to the loss of a single fluorine atom, highlighting the critical effect of fluorine on the photoluminescence of these Ir(III) complexes. Finally, intensive mechanistic studies including HPLC-mass analysis, 1H-NMR, and 19F-NMR studies demonstrate that the formation of complex 2 should involve a critical β-hydride elimination of Ir(III)-alkoxide intermediate and the participation of Ir-hydride and/or Ir-fluoride intermediates.

•Amidate iridium(III) bis(2-quinolyl)phenyl compounds with four-member ring structure.•Amidate influenced absorption and emission energies of the Ir complexes.•These Ir complexes were investigated by DFT calculations.•Amidate iridium(III) compound has been employed for polymerization reaction.The synthesis, characterization by X-ray crystallography, photophysical properties and DFT calculations of bis(2-quinolyl)phenyl iridium complexes are reported here. The quinolyl-substituted iridium(III) compounds, which have amidate ancillary ligand, formed four-membered ring structure and have been employed for polymerization reaction and gave the metal-containing amide homopolymers.The synthesis, characterization by X-ray crystallography, photophysical properties and DFT calculations of bis(2-quinolyl)phenyl iridium complexes are reported here. The quinolyl-substituted iridium(III) compounds, which have amidate ancillary ligand, formed four-membered ring structure and have been employed for polymerization reaction and gave the metal-containing amide homopolymers.

A series of quinolyl-substituted iridium(III) compounds with an amidate ancillary ligand and a four-membered-ring structure have synthesized and characterized by X-ray crystallography for the first time. The strategy of varying the amidate ancillary ligand gives photoluminescence in the green and orange-yellow region, while pyridyl-substituted compounds only gave green emission. The HOMO and LUMO energy levels and compositions of quinolyl-substituted iridium(III) compounds were investigated by DFT calculations. This showed that the quinoline and amidate ancillary ligand influence the absorption and emission energies of these complexes by tuning the HOMO energies. In addition, the TG experiment showed quinolyl-substituted iridium(III) compounds have excellent stability. ECL experiments were also explored in this paper.

In this paper, copper(I) amidate complexes (2–3), proposed intermediates in copper-catalyzed Goldberg reaction, have been prepared and characterized by elemental analysis, IR, 1H NMR and X-ray crystallography. Ancillary ligand bis(diphenylphosphino)ferrocene (dppf) has contributed greatly to the stability of the copper–amidate complexes due to its strong chelating ability and weak intermolecular interactions. Thermal gravimetric analyses are carried out to determine the thermal competency of complexes 2–3 as the intermediates of the high-temperature Goldberg reactions. Reaction of complexes 2 and 3 with aryl halides generates the N-arylation products 5–8, accompanied by the formation of a copper(I) complex Cu(dppf)X (X = I or Br) 4, which has been determined by LC-MS analysis. These results provide new evidence for the mechanism of copper(I)-catalyzed Goldberg reaction.

A μ–η2:η2-carbonato-bridged copper(I) dinuclear complex 3, of formula [Cu2(μ-CO3)(dppf)2]·[PhCONPh]·[Na(H2O)4]·CH2Cl2·2H2O (dppf = 1,1′-bis(diphenylphosphino)ferrocene) was synthesized and characterized by IR, 1HNMR and X-ray diffraction method. When chloride-bridged copper(I) complex reacted with N-phenyl benzamide with sodium methoxide as base under air or carbon dioxide atmosphere, the carbonate-bridged copper(I) complex from CO2 fixation was obtained. Cyclic voltammetry experiments of dppf ligand and complex 3 illustrate that the oxidation occurs only at the ferrocene(II) center, but complex 3 oxidizes at more negative potential than the uncoordinated dppf ligand. The thermal stability of complex 3 was also reported and discussed.A μ-η2:η2-carbonato-bridged dimeric copper(I) complex (3) containing bis(diphenylphosphino)ferrocene ligand was synthesized from CO2 fixation. The reaction mechanism was discussed in detail. Complex 3 is thermally stable from room temperature to 124 °C despite some uncoordinated molecules; it is not sensitive to moisture and oxygen so it is stable in air for months. The reaction has provided a simple and cheap method for fixation of CO2.Highlights► We obtain a μ-carbonato-bridged copper(I) complex from CO2 fixation reaction. ► We discuss the reaction mechanism in detail. ► Cyclic voltammetry experiments are applied to determine electrochemical reversibility. ► Thermal decomposition and stability is characterized by TG.

The synthesis, characterization and photoluminescent properties of a dinuclear Ir complex with a μ-η1:η2-phenylquinolyl bridge and an end-on dinitrogen ligand are reported herein. DFT studies on its electronic structure and photophysical properties are also presented.

Two novel iridium(III) complexes containing 2-(4,6-difluorophenyl)pyridyl cyclometalating ligand and amidate ancillary ligands were synthesized and characterized by NMR and X-ray crystallographic methods. Photophysical properties including UV–vis absorption and photoluminescence spectra were studied, indicating that the electronic properties of the amidate ancillary ligand exhibit a significant effect on the emitting excited states of these iridium(III) amidate complexes and thus lead to different emission colors.Two new photoluminescent iridium(III) 2-(4,6-difluorophenyl)pyridyl complexes containing N-phenylbenzamidate and N-phenylacetamidate ancillary ligands were synthesized and characterized. Photophysical property studies show that the electronic properties of amidate ancillary ligand exhibit a critical effect on the emission color of the Ir(III) amidate complexes.Research highlights► Ir(III) 2-(4,6-difluorophenyl)pyridyl complexes with amidate ancillary ligand. ► Tuning emission color by simply altering the structure of amidate ligand. ► Amidate ligands affect the energy level of emitting excited states. ► Amidate ligands affect inter-ligand energy transfer.

Density functional theory method B3LYP was used to study the mechanism of amination reactions between aryl bromides and alkylamines catalyzed by Cu(I) species with 1,3-diketone ligands. Through systematic evaluation of the relative concentrations of possible copper species in solution and oxidative addition of these species with aryl bromide, we propose that the active catalyst is a neutral three-coordinate 1,3-diketonate-ligated Cu(I)(amine) complex. Oxidative addition of aryl bromide to this species is the rate-limiting step of the catalytic cycle. These results explain why for basic alkylamine substrates, diamine ligands are ineffective, because for diamine ligands, formation of such a neutral Cu(I) complex containing both ligand and nucleophile is thermodynamically unfavorable. Interestingly, the active catalyst Cu(I)(diketonate)(amine) complex is essentially akin to the active catalyst Cu(I)(diamine)(amidate) proposed in copper-catalyzed coupling of amides with aryl halides. Therefore, this implies that for an acidic substrate a neutral ligand is preferred, while for basic substrate an acidic ligand is necessary to achieve high efficiency. Our results also show that anionic copper(I) complexes with two molecules of deprotonated necleophiles or ligands are not reactive. Therefore, the wise selection of appropriate ligand and base combinations for a specific nucleophile to generate a neutral copper(I) complex containing both ligand and nucleophile is the key point to the success of these copper-catalyzed cross-coupling reactions. These insights should be helpful for our understanding and further development of more efficient reaction protocols for copper-catalyzed coupling of more challenging electrophiles such as aryl chlorides and tosylates and other types of nucleophiles.

The syntheses, structures, and photophysical properties of a series of iridium(III) bis(2-pyridyl)phenyl complexes, (ppy)2Ir(LX) (LX = amide ligands), are described. The complex (ppy)2Ir(N-phenylmethacrylamide) (5), bearing an acrylamidate ligand, has been further employed for polymerization to generate the metal-containing homopolymer poly((ppy)2Ir(N-phenylmethacrylamide)) (6). In addition, the complexes (ppy)2Ir(acetylaniline) (2) and (ppy)2Ir(N-phenylbenzamide) (3) have been structurally characterized by X-ray crystallography. It was found that the amidate ligand binds to the Ir center in an imine/alkoxide mode via a four-membered, nearly planar ring (N−Ir−O−C); the limited delocalization is supported by the lengthened C−O bond compared to the C−N bond length in the amidate backbone and no strong absorption around 1650 cm−1 in the infrared spectra. The photophysical and electrochemical properties of these complexes were then studied. The maximum emission wavelengths ranging from 510 to 548 nm as well as the ΔEp values varying from 2.55 to 2.77 V can be attributed to the different effects of ancillary amide ligands tolerating different electronic characters. The HOMO and LUMO energy levels and compositions of the iridium complexes were investigated by DFT calculations. The amidate ancillary ligands affect the absorption and emission energies of these complexes by tuning the HOMO energies.

C60 covalently connected with dicyanovinyl functionalized tris[4-(2-thienyl)phenyl]amine [C60-TTPA(DCV)] (compound 1) has been successfully prepared and it was found to exhibit excellent solubility in common organic solvents with a broad visible-light harvest. The theoretical calculation of its molecular geometry and electronic structure indicates that the TTPA(DCV) moiety and C60 part are acting as donor and acceptor respectively; By comparing with the UV–visible absorption spectra of amine 2, the slight red shift of compound 1 could explain the existence of a small portion of charge transport between the two parts; and the fluorescence spectra of compound 1 show that the intramolecular photo-induced electron transfer from the TTPA(DCV) to C60 is the main pathway for the emission quenching.

The synthesis, characterization and photoluminescent properties of a dinuclear Ir complex with a μ-η1:η2-phenylquinolyl bridge and an end-on dinitrogen ligand are reported herein. DFT studies on its electronic structure and photophysical properties are also presented.

β-Diketiminato cyclopentadienyl and ferrocenylethynyl germylenes LGeR (L = HC[C(Me)N-2,6-iPr2C6H3]2, R = Cp (1) and CCFc (2)) were prepared and utilized to synthesize the GeTe bond species. Reactions of 1, 2, and LGeCCPh (3) with an excess of Te powder proceeded in toluene under reflux successfully yielded germanetellurone L(R)GeTe (R = Cp (4), CCFc (5), and CCPh (6)). Further reaction of 4 with GeCl2·dioxane at −78 °C resulted in L(Cp)GeTe(GeCl2) (7), the first example of a germylene germanetellurone adduct. Both compounds 4 and 7 contain two isomers that are generated by the simultaneous 1,2-H- and 1,3-H-shifts over the Cp ring at the Ge atom. The reactions of L(Me)GeE with AuC6F5·SC4H8 at room temperature led to pentafluorophenyl gold(I) germanethione and germaneselone compounds L(Me)GeE(AuC6F5) (E = S (8) and Se (9)). The formation of compounds 7–9 exhibits a rare nucleophilic coordination reaction pathway by the GeE (E = S, Se, Te) bond towards the metal-containing Lewis acidic species. The structures of compounds 1, 2, and 4–9 are studied by the NMR and/or IR spectroscopy and X-ray crystallography.

In this paper, copper(I) amidate complexes (2–3), proposed intermediates in copper-catalyzed Goldberg reaction, have been prepared and characterized by elemental analysis, IR, 1H NMR and X-ray crystallography. Ancillary ligand bis(diphenylphosphino)ferrocene (dppf) has contributed greatly to the stability of the copper–amidate complexes due to its strong chelating ability and weak intermolecular interactions. Thermal gravimetric analyses are carried out to determine the thermal competency of complexes 2–3 as the intermediates of the high-temperature Goldberg reactions. Reaction of complexes 2 and 3 with aryl halides generates the N-arylation products 5–8, accompanied by the formation of a copper(I) complex Cu(dppf)X (X = I or Br) 4, which has been determined by LC-MS analysis. These results provide new evidence for the mechanism of copper(I)-catalyzed Goldberg reaction.

In this paper, a C–F bond activation reaction of a chloro-bridged iridium(III) dimer (dfppy)2Ir(μ-Cl)2Ir(dfppy)2 (1) (dfppy denotes 2-(4,6-difluorophenyl)pyridyl) in the presence of sodium methoxide has been reported, leading to the formation of a heteroleptic cyclometalated iridium(III) fluorophenylpyridine complex 2. HPLC-mass analysis confirmed the release of formaldehyde in the product mixture. When sodium benzyloxide was used as the base, complex 2 was also generated with the release of a benzaldehyde derivative. Complex 2 has been fully characterized by 1H-NMR, 19F-NMR and X-ray crystallographic methods, confirming the partial loss of one of the fluorine atoms on one of the cyclometalated phenylpyridyl ligands. Photophysical studies of complex 2 show that it has a similar absorption spectrum to that of Ir(III)(dfppy)3. However, the emission spectrum shows a red shift maximum emission band at 478 nm due to the loss of a single fluorine atom, highlighting the critical effect of fluorine on the photoluminescence of these Ir(III) complexes. Finally, intensive mechanistic studies including HPLC-mass analysis, 1H-NMR, and 19F-NMR studies demonstrate that the formation of complex 2 should involve a critical β-hydride elimination of Ir(III)-alkoxide intermediate and the participation of Ir-hydride and/or Ir-fluoride intermediates.