Search results for "Phosphore"
showing 10 items of 114 documents
Hybrid ferrocene ligands (P, N) : synthesis, coordination to metals and applications in arylation coupling catalysis
2017
The research theme developed during this thesis concerns the development of new hybrid ferrocene hybrid (P, N) ligands with controlled conformation, robust and stable to air. These hybrid tetradent ligands comprise two types of coordinating functions with distinct steric and electronic properties. Their coordination chemistry with metals such as gold or palladium has been studied and some isolated Au (I) complexes have been used in the arylation coupling catalysis of aryl iodides.
Supramolecular Construction of Cyanide-Bridged Re I Diimine Multichromophores
2019
The reactions of labile [Re(diimine)(CO)3(H2O)]+ precursors (diimine = 2,2′-bipyridine, bpy; 1,10-phenanthroline, phen) with dicyanoargentate anion produce the dirhenium cyanide-bridged compounds [{Re(diimine)(CO)3}2CN)]+ (1 and 2). Substitution of the axial carbonyl ligands in 2 for triphenylphosphine gives the derivative [{Re(phen)(CO)2(PPh3)}2CN]+ (3), while the employment of a neutral metalloligand [Au(PPh3)(CN)] affords heterobimetallic complex [{Re(phen)(CO)3}NCAu(PPh3)]+ (4). Furthermore, the utilization of [Au(CN)2]−, [Pt(CN)4]2–, and [Fe(CN)6]4–/3– cyanometallates leads to the higher nuclearity aggregates [{Re(diimine)(CO)3NC}xM]m+ (M = Au, x = 2, 5 and 6; Pt, x = 4, 7 and 8; Fe, x…
p–n Metallophosphor based on cationic iridium(iii) complex for solid-state light-emitting electrochemical cells
2011
An ionic transition-metal complex for improved charge transporting properties was designed, containing both n-type dimesitylboryl (BMes2) and p-type carbazole groups. The complex, [Ir(Bpq)2(CzbpyCz)]PF6 (1) (Bpq = 2-[4-(dimesitylboryl)phenyl] quinoline, CzbpyCz = 5,5′-bis(9-hexyl-9H-carbazol-3-yl)-2,2′-bipyridine) and its equivalent in which the BMes2 groups were substituted with carbazole moieties were evaluated on the photoluminescence and excited state properties in detail. According to the photophysical and electrochemical properties, we concluded that the BMes2 groups can increase the conjugation length of the cyclometalated C^N ligands and greatly enhance the phosphorescence efficienc…
<title>Time-resolved fluorescence study of interaction of the monoclonal anticoproporphyrin antibodies and (Pt-)coproporphyrin</title>
1995
Mechanisms of ligand binding by monoclonal anti-coproporphyrin antibodies are studied by steady-state and time-resolved fluorescence spectroscopy by use of a picosecond laser system. The antibodies quench the coproporphyrin (CP) fluorescence, but the CP fluorescence spectra show a strong shift of maxima at high concentrations of antibodies (Ab) or their Fab fragment. This can be explained by a special type of Ab or Fab dimerization. Fluorescence decays of CP are measured at different concentrations of Ab and different pH values. The following deconvolution procedure based on the non-linear least squares method reveals a two- exponential character of the fluorescence decay. Data obtained by …
Electronic nature of the emitting triplet in SF 5 -substituted cationic Ir(III) complexes
2018
Abstract A theoretical density functional theory study has been performed on a family of cationic iridium(III) complexes of the form [Ir(C^N)2(dtBubpy)]+ (dtBubpy = 4,4′-di-tert-butyl-2,2′-bipyridine), that incorporate 2-phenylpyridine (1, 2) and 1-phenylpyrazole (3, 4) cyclometallating C^N ligands functionalized with SF5 groups. The goal is to investigate the effect that the inclusion of SF5 groups in meta (1, 3) and para position (2, 4) with respect to the Ir–C bond has on the electronic nature of the emitting triplet state and the emission wavelength. The attachment of the electron-withdrawing groups induces the stabilization of the molecular orbitals localized on the C^N ligands and, in…
Toward luminescence vapochromism of tetranuclear AuI-Cu I clusters
2013
A family of triphosphine gold–copper clusters bearing aliphatic and hydroxyaliphatic alkynyl ligands of general formula [HC(PPh2)3Au3Cu(C2R)3]+ (R = cyclohexyl (1), cyclopentyl (2), But (3), cyclohexanolyl (4), cyclopentanolyl (5), 2,6-dimethylheptanolyl (6), 2-methylbutanolyl (7), diphenylmethanolyl (8)) was synthesized via a self-assembly protocol, which involves treatment of the (AuC2R)n acetylides with the (PPh2)3CH ligand in the presence of Cu+ ions and NEt3. Addition of Cl– or Br– anions to complex 8 results in coordination of the halides to the copper atoms to give neutral HC(PPh2)3Au3CuHal(C2COHPh2)3 derivatives (Hal = Cl (9), Br (10)). The title compounds were characterized by NMR …
Pyrenyl substituted 1,8-naphthalimide as a new material for weak efficiency-roll-off red OLEDs: a theoretical and experimental study
2018
Based on the theoretical calculations of excited states and semiconducting properties, a new 1,8-naphthalimide derivative having an electron-donating 1-pyrenyl group at the C-4 position was designed and synthesized. This derivative exhibited an excellent thermal stability and bipolar charge carrier transport ability. It was successfully utilized as a host in red phosphorescent organic light-emitting diodes showing an efficient energy transfer from the host to the phosphorescent emitter. The derivative may be a single material electroplex-forming host for PhOLEDs. The best fabricated red emitting device demonstrated maximum current, power, and external quantum efficiencies of 10.8 cd A−1, 7 …
Strong circularly polarized luminescence of an octahedral chromium(iii) complex
2019
The chiral spin-flip luminophore [Cr(ddpd)2]3+ can be resolved into enantiopure material by chiral HPLC. The corresponding enantiomers show very high luminescence dissymmetry factors of up to ∣glum ∣≈ 0.093 in circularly polarized luminescence (CPL) measurements for the "ruby-like" phosphorescence transition 2E/2T1 → 4A2 in the near-IR region around λ ≈ 775 nm.
[Cr(ddpd) 2 ] 3+ : A Molecular, Water‐Soluble, Highly NIR‐Emissive Ruby Analogue
2015
Bright, long-lived emission from first-row transition-metal complexes is very challenging to achieve. Herein, we present a new strategy relying on the rational tuning of energy levels. With the aid of the large N-Cr-N bite angle of the tridentate ligand ddpd (N,N'-dimethyl-N,N'-dipyridine-2-ylpyridine-2,6-diamine) and its strong σ-donating capabilities, a very large ligand-field splitting could be introduced in the chromium(III) complex [Cr(ddpd)2](3+), that shifts the deactivating and photoreactive (4)T2 state well above the emitting (2)E state. Prevention of back-intersystem crossing from the (2)E to the (4)T2 state enables exceptionally high near-infrared phosphorescence quantum yields a…
Luminescent Pt-II and Pt-IV Platinacycles with Anticancer Activity Against Multiplatinum-Resistant Metastatic CRC and CRPC Cell Models
2020
Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide variety of tumours. Nevertheless, the acquisition of platinum resistance is utterly common, ultimately cornering conventional platinum drugs to only palliative in many patients. Thus, encountering alternatives that are both effective and non-cross-resistant is urgent. In this work, we report the synthesis, reduction studies, and luminescent properties of a series of cyclometallated (C,N,N')PtIV compounds derived from amine- imine ligands, and their remarkable efficacy at the high nanomolar range and complete lack of cross57 resistance, as an intrinsic property of the platinacycle, against multipl…