Beta-diketonate Derivatives Research Articles

O,N-coordinated Ni(II) beta-diketonate derivatives: Synthesis, thermal properties, MOCVD applications

Ni(II) β-diketonate derivatives – β-iminoketonates with general formula Ni(RC(O)CHC(NH)R1)2 (R=R1=CH3, C(CH3)3; R=CF3, R1=CH3, C(CH3)3; R=C(OCH3)(CH3)2, R1=CH(CH3)2, C(CH3)3) and Ni(1,3-diaminopropane)(R2C(O)CHC(O)R3)2 (R2=C(CH3)3, R3=CF3, C(CH3)3) – were synthesized with high yields. The products are stable to air and moisture, and soluble in most common organic solvents. Elemental analysis, X-ray studies, and IR spectroscopy were used to characterize the synthesized compounds. The thermal properties of the compounds in the solid state were investigated by means of TG. The temperature dependence of the saturated vapor pressures was studied using the flow method. Thermodynamic parameters of the vaporization process, ΔHТ* and ΔS°Т*, were calculated. MOCVD test experiments were carried out at low pressure (10Torr) on Ta/Si substrates using Ni(i-tmhd)2 and Ni(pda)(tmhd)2 (i-Htmhd — 2,2,6,6-tetramethyl-4-imino-heptane-2-on, pda — 1,3-diaminopropan, Htmhd — 2,2,6,6-tetramethyl-heptane-3,5-dion) as precursors. The vaporization temperatures were 120°C for Ni(pda)(tmhd)2 and 155°C for Ni(i-tmhd)2. The substrate temperatures were 210–350°C. The Ni-containing films were investigated by means of X-ray diffraction analysis, SEM, and XPS.

Sсandium(III) Beta-diketonate Derivatives as Precursors for Oxide Film Deposition by CVD

Abstract Complexes with acetylacetone Sc(acac)3, dipivaloylmethane Sc(thd)3, 2,2,6,6–tetramethyl-4-fluoro-3,5-heptanedione Sc(tfhd)3, pivaloyltrifluoroacetone Sc(ptac)3, trifluoroacetylacetone Sc(tfac)3, and hexafluoroacetylacetone Sc(hfac)3 were synthesized, purified and identified by elemental analysis, m.p., IR and NMR spectroscopy, and mass spectrometry. The thermal behaviour of the synthesized compounds in the solid state was investigated by the method of difference-scanning calorimetry in vacuum. As a result the thermodynamic characteristics of the melting processes were determined. The temperature dependences of saturated and unsaturated vapour pressure of complexes under study were measured by static method with membrane-gauge manometers. The average molecular weight of gas calculated from the experimental data on unsaturated vapours using ideal gas law was close to the molecular weight of monomer for all investigated compounds. Decomposition temperatures of compounds under study were defined as the temperature above that pressure changes became irreversible. The information about melting and decomposition processes were taken into account at measuring saturated vapour pressure of complexes. The row of volatility Sc(hfac)3 > Sc(ptac)3 > Sc(tfac)3 > Sc(thd)3 ≥ Sc(tfhd)3 > Sc(acac)3 was determined from the p–T dependences obtained. Above information about thermal behaviour of complexes enabled one to use it as a guide for CVD experiments aimed at achieving oxide films with high optical properties. Precursor chosen for film deposition was Sc(thd)3 The Sc2O3 film deposition conditions were following: the gas-carrier rate 1 l/h, He gas-reagent rate 10 l/h, total pressure 10 Torr, evaporator temperature 105-110С, substrate temperature 450- 650С, substrate Si(100). Ellipsometry was applied to characterize the film thickness and refractive index. The morphology and the composition of the films were determined with XPS and SEM.

Thermal properties of volatile ruthenium(III) complexes

Complexes of ruthenium(III) with the following beta-diketone derivatives: 2,4-pentanedione (Ru(acac)3), 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (Ru(hfac)3), and 2-methoxy-2,6-dimethyl-3,5-heptanedione (Ru(mdhd)3) were synthesized, purified, and identified by chemical analysis and melting points. By difference-scanning calorimetry (DSC) in vacuum the thermodynamic characteristics of melting processes were defined. Using the static method with quartz membrane zero-manometer, the temperature dependencies of saturated and unsaturated vapor pressure were obtained for Ru(hfac)3. The standard thermodynamic characteristics of vaporization processes enthalpy ∆HT* and entropy ∆S°T* were determined.

Copper Extraction Kinetics by Beta-Diketone Derivatives (Acylpyrazolones and Acylisoxazolones) in Water/Chloroform Biphasic System

Copper(II) extraction and back-extraction rates were determined in a water/chloroform system using a bell-shaped transport cell. Various 1-phenyl-3-methyl-4-acyl-pyrazol-5-ones (with acyl = benzoyl, 2-thenoyl, octadecanoyl, p-tert-butylbenzoyl, 3-phenyl-propanoyl, and iso-nonanoyl) and 3-phenyl-4-acylisoxazol-5-ones (with acyl = benzoyl and p-tert-butylbenzoyl) were considered. The back-extraction rate is shown to be limited by the diffusion of the complex in the organic unstirred layer, whatever the stirring speed and whatever the ligand considered. At low stirring speed, the extraction rate appears to be limited by the diffusion of either a complex or a ligand species in the unstirred layers, depending on the pH. At high stirring speed, the extraction rate is limited by the interfacial complexation. The extraction rate dependence on side-group variation cannot be correlated with hydrophobicity or acidity of the extractants and may be explained by structural differences of the CO vicinal group of the acyl.

Effect of Different Alkyl Groups at the N-Position on the Luminescence of Carbazole-Based β-Diketonate Europium(III) Complexes

A series of carbazole-based beta-diketone derivatives and their europium(III) ternary complexes Eu(N-Cx)(3)phen were designed and synthesized, where N-Cx denotes carbazole-based beta-diketonates with different alkyl substituents at N-position of the carbazole ring and phen is 1,10-phenethroline. Thermogravimetric analysis (TGA) shows that the decomposition temperature of the complexes is over 360 degrees C. UV-visible absorption spectroscopy, photoluminescence (PL), and the luminescence quantum yield of the Eu(III) complexes were measured and compared with each other, and the effect of different substituted-alkyls at N-position in the carbazole ring on the photoluminescence was discussed in details, indicating there exists a competition between the absorption capacity and the energy transfer efficiency for the complexes when the structure of the substituted-alkyls changes. The triplet state energy levels of the beta-diketonate ligands in the complexes are higher than that of the lowest excited level of Eu(3+) ion, (5)D(0), so the photoluminescence mechanism of the Eu(III) complexes was proposed as a ligand-sensitized luminescence process. Red LEDs were fabricated by precoating the complexes onto 395 nm emitting InGaN chips. All the results show that this series of Eu(III) complexes is a promising candidate as a red component in fabrication of NUV-based white LEDs.

Study of temperature dependencies of saturated vapor pressure of ruthenium(III) beta-diketonate derivatives

Complexes of ruthenium(III) with the following beta-diketones: 2,4-pentanedione (Ru(acac)3), 1,1,1-tri- fluoro-2,4-pentanedione (Ru(tfac)3), 2,2,6,6-tetramethyl-3, 5-heptanedione (Ru(thd)3), 2,2,6,6-tetramethyl-4-fluoro- 3,5-heptanedione (Ru(tfhd)3) and 1,1,1-trifluoro-5,5-dime- thyl-2,4-hexanedione (Ru(ptac)3) were synthesized and identified by means of mass spectrometry. By effusion Knudsen method with mass spectrometric registration of gas phase composition the temperature dependencies of satu- rated vapor pressure were measured for ruthenium(III) compounds and the thermodynamic characteristics of vaporization processes enthalpy DHT* and entropy DS oof

Syntheses and ligand interconversions of copper(ii) derivatives of the metalloligand [Pt2(µ-S)2(PPh3)4

The reactivity of the metalloligand [Pt2(micro-S)2(PPh3)4] towards a variety of copper(II)-ligand systems has been studied. Reaction of [Pt2(mu-S)2(PPh3)4] with copper(II) halide complexes [CuCl2L](L = 2,2'-bipyridine and 1,10-phenanthroline) gave trinuclear dicationic products [Pt2(mu-S)2(PPh3)4CuL]2+, and the 8-hydroxyquinolinate (hq) complex [Cu(hq)2] gave [Pt2(mu-S)2(PPh3)4Cu(hq)]+, isolated as their BPh4- or PF6- salts. Related cationic complexes with other ancillary amine ligands (1,2-diaminoethane, 1,2-diaminopropane, 1,2-diaminocyclohexane) were obtained by reactions of [Pt2(mu-S)2(PPh3)4] with CuCl2 and the amine. In contrast, reaction of [Pt2(mu-S)2(PPh3)4] with CuCl2 and NH3 in methanol gave the intensely blue methoxy-bridged dicopper complex [{Pt(2)(mu-S)2(PPh3)4Cu(OMe)}2]2+, isolated as its hexafluorophosphate salt. Copper beta-diketonate complexes reacted with [Pt2(mu-S)2(PPh3)4] giving [Pt2(mu-S)2(PPh3)4Cu(beta-diketonate)]+PF6- complexes, with the CH3COCHCOCH3(acac) and CF3COCHCO(2-thienyl)(tta) derivatives characterised by X-ray structure determinations. The local Cu(II) environment ranges from distorted square-planar to an intermediate form of square-planar and tetrahedral. The beta-diketonate derivatives show varying stability towards methanolysis, giving [{Pt2(mu-S)2(PPh3)4Cu(OMe)}2]2+.

Chemical Adaptor Immunotherapy: Design, Synthesis, and Evaluation of Novel Integrin-Targeting Devices

A series of beta-diketone derivatives of RGD peptidomimetics that selectively bind to alphavbeta3 and alphavbeta5 integrins were synthesized and covalently docked to the reactive lysine residues of monoclonal aldolase antibody 38C2. The resulting targeting devices strongly and selectively bound to human cancer cells expressing integrins alphavbeta3 and alphavbeta5 as analyzed by flow cytometry. In vitro and in vivo studies revealed that these novel integrin-targeting devices efficiently inhibit tumor growth. Thus, the combination of beta-diketone derivatives of RGD peptidomimetics that target cell surface integrins alphavbeta3 and alphavbeta5 with monoclonal aldolase antibodies through formation of a covalent bond of defined stoichiometry holds promise as a new approach to cancer therapy.