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101.
Daniel Carmona Roberto Medrano Isabel T. Dobrinovich Fernando J. Lahoz Joaquina Ferrer Luis A. Oro 《Journal of organometallic chemistry》2006,691(26):5560-5566
Half-sandwich complexes of formula [(ηn-ring)MClL]PF6 [L = (S)-2-[(Sp)-2-(diphenylphosphino)ferrocenyl]-4-isopropyloxazoline; (ηn-ring)M = (η5-C5Me5)Rh; (η5-C5Me5)Ir; (η6-p-MeC6H4iPr)Ru; (η6-p-MeC6H4iPr)Os] have been prepared and spectroscopically characterised. The molecular structures of the rhodium and iridium compounds have been determined by X-ray crystallography. The related solvate complexes [(η5-C5Me5)ML(Me2CO)]2+ (M = Rh, Ir) are active catalysts for the Diels-Alder reaction between methacrolein and cyclopentadiene. 相似文献
102.
1INTRODUCTIONRecently,considerableattentionhasbeenpaidtotheinvestigationofcoordinationchemistryofmanganeseindifferentoxidationstatesnotonlybecauseofthediscoveryoftightlyboundmanganeseatomsinvariousbiomolecules[libutalsobecauseoftheirinterestingstructural,magneticandspectroscopicfeatures.Wehavepreparedseveralcomplexesofmanganese(n)withdifferentligands.Thestructuresandfeaturesofthesecompoundsarestudiedsystematically.Inthispaperwedescribethestructureofthecomplexwiththeligandsofphenanthroline… 相似文献
103.
Adrenaline was found to inhibit strongly the electrochemiluminescence (ECL) from the Ru(bpy)32+/tripropylamine system when a working Pt electrode was maintained at 1.05 V (versus Ag/AgCl) in pH 8.0 phosphate buffer. On this basis, a flow injection (FI) procedure with inhibited electrochemiluminescence detection has been developed for determination of adrenaline. The method exhibited a good reproducibility, sensitivity, and stability with a detection limit (signal-to-noise ratio = 3) of 7.0×10−9 mol l−1 and dynamic concentration range of 2×10−8 to 1×10−4 mol l−1. The relative standard deviation was 2.2% for 1.0×10−6 mol l−1 adrenaline (n=11). The method was successfully applied to the determination of adrenaline in pharmaceutical samples. Moreover, ECL emission spectra, UV-Vis absorption spectra and cyclic voltammograms of Ru(bpy)32+/tripropylamine/adrenaline were studied. The inhibition mechanism has been proposed as the interaction of electrogenerated Ru(bpy)32+* and the o-benzoquinone derivatives, adrenochrome and adrenalinequinone, at the electrode surface. 相似文献
104.
通过金属离子替代的方法设计了催化氧化性能不同的Mg-Al-Ru-CO3类水滑石、Co-Al-Ru-CO3类水滑石和Ru-Co(OH)2-CeO2等三种催化剂. XRD实验表明钌部分替换制得的Mg-Al-Ru-CO3和Co-Al-Ru-CO3可保持水滑石的结构; 但用铈替代铝之后得到的Ru-Co(OH)2-CeO2催化剂无法保持水滑石的结构, 而是由氢氧化钴和二氧化铈的微晶组成. XPS 和Ru K-edge XAFS的测试结果证实Mg-Al-Ru-CO3催化剂中钌被等键长的6个氧原子包围, 该催化剂可有效地催化氧化醇类; Co-Al-Ru-CO3催化剂中钌被两种键长不等的6个氧原子包围, 其中短键长的Ru═O是催化氧化性能增强的原因; Ru-Co(OH)2-CeO2催化剂中钌被两种键长不等的5个氧原子包围, 其对于各类醇均有高效的催化氧化性能, 原因归功于配位数少的钌物种. 相似文献
105.
Ramanathan Hariram Bidyut Kumar Santra Goutam Kumar Lahiri 《Journal of organometallic chemistry》1997,540(1-2):155-163
The reaction of RuII(PPh3)3X2 (X = Cl, Br) with o-(OH)C6H4C(H)=N-CH2C6H5 (HL) under aerobic conditions affords RuII(L)2(PPh3)2, 1, in which both the ligands (L) are bound to the metal center at the phenolic oxygen (deprotonated) and azomethine nitrogen and RuIII(L1)(L2)(PPh3), 2, in which one L is in bidentate N,O form like in complex 1 and the other ligand is in tridentate C,N,O mode where cyclometallation takes place from the ortho carbon atom (deprotonated) of the benzyl amine fragment. The complex 1 is unstable in solution, and undergoes spontaneous oxidative internal transformation to complex 2. In solid state upon heating, 1 initially converts to 2 quantitatively and further heating causes the rearrangement of complex 2 to the stable RuL3 complex. The presence of symmetry in the diamagnetic, electrically neutral complex 1 is confirmed by 1H and 31P NMR spectroscopy. It exhibits an RuII → L, MLCT transition at 460 nm and a ligand based transition at 340 nm. The complex 1 undergoes quasi-reversible ruthenium(II)—ruthenium(III) oxidation at 1.27V vs. SCE. The one-electron paramagnetic cyclometallated ruthenium(III) complex 2 displays an L → RuIII, LMCT transition at 658 nm. The ligand based transition is observed to take place at 343 nm. The complex 2 shows reversible ruthenium(III)—ruthenium(IV) oxidation at 0.875V and irreversible ruthenium(III)—ruthenium(II) reduction at −0.68V vs. SCE. It exhibits a rhombic EPR spectrum, that has been analysed to furnish values of axial (6560 cm−1) and rhombic (5630 cm−1) distortion parameters as well as the energies of the two expected ligand field transitions (3877 cm−1 and 9540 cm−1) within the t2 shell. One of the transitions has been experimentally observed in the predicted region (9090 cm−1). The first order rate constants at different temperatures and the activation parameter ΔH#/ΔS# values of the conversion process of 1 → 2 have been determined spectrophotometrically in chloroform solution. 相似文献
106.
Catherine D. Clark Morton Z. Hoffman D. Paul Rillema Quinto G. Mulazzani 《Journal of photochemistry and photobiology. A, Chemistry》1997,110(3):285-290
The photophysics of three complexes of the form Ru(bpy)3−(pypm)2+ (where bpy2,2′-bipyridine, pypm 2-(2′-pyridyl)pyrimidine and P=1, 2 or 3) was examined in H2O, propylene carbonate, CH3CN and 4:1 (v/v) C2H5OH---CH3OH; comparison was made with the well-known photophysical behavior of Ru(bpy)32+. The lifetimes of the luminescent metal-to-ligand charge transfer (MLCT) excited states were determined as a function of temperature (between −103 and 90 °C, depending on the solvent), from which were extracted the rate constants for radiative and non-radiative decay and ΔE, the energy gap between the MLCT and metal-centered (MC) excited states. The results indicate that *Ru(bpy)2(pypm)2+ decays via a higher lying MLCT state, whereas *Ru(pypm)32+ and *Ru(pypm)2(bpy)2+ decay predominantly via the MC state. 相似文献
107.
The reactions of [RuHCl(CO)(PPh3)3] and [(C6H6)RuCl2]2 with 2-benzoylpyridine have been examined, and two novel ruthenium(II) complexes – [RuCl(CO)(PPh3)2(C5H4NCOO)] and [RuCl2(C12H9NO)2] – have been obtained. The compounds have been studied by IR and UV–Vis spectroscopy, and X-ray crystallography. The molecular orbital diagrams of the complexes have been calculated with the density functional theory (DFT) method. The spin-allowed singlet–singlet electronic transitions of the compounds have been calculated with the time-dependent DFT method, and the UV–Vis spectra of the compounds have been discussed on this basis. 相似文献
108.
Wolfdieter A. Schenk Michael Stubbe Michael Hagel 《Journal of organometallic chemistry》1998,560(1-2):257-263
The P–Ph cleavage of phenyldibenzophosphole (1) with lithium in THF gives lithium dibenzophospholide (2). Reaction of 2 with ethyleneglycol ditosylate produces the known chelate ligand 1,2-bis(dibenzophospholyl)ethane (3) in good yield. Similarly, 2 and (2R,3R)-butanediol ditosylate give the new chiral chelate ligand (2S,3S)-bis(dibenzophospholyl)butane (4). Ligand exchange of [CpRu(PPh3)2Cl] with 3 or 4 yields the halfsandwich complexes [CpRu(C12H8PC2H4PC12H8)Cl] (5) and [CpRu((S,S)-C12H8PCHMeCHMePC12H8)Cl] (6). Complex 6 was characterized crystallographically (monoclinic, space group P21 (no. 4), a=820.6(4), b=1501.0(3), c=1172.8(6) pm, β=108.87(2)°, V=1.367(1)×109 pm3, Z=2). The most conspicuous feature of the structure of 6 is the perfect coplanarity of the two dibenzophosphole moieties imposed by their steric interaction with the Cp ligand. Complex 6 and the thiophene complex [CpRu((S,S)-C12H8PCHMeCHMePC12H8)(SC4H4)]BF4 (7) derived therefrom are remarkably unreactive with regard to ligand substitutions. A possible explanation is the lack of intramolecular –C stabilization en route to the transition state of ligand substitution. The enantiomeric purity of 6 and 7 could nevertheless be demonstrated by conversion to diastereomerically pure [CpRu((S,S)-C12H8PCHMeCHMePC12H8)((S)-CNCHMePh)]BF4 (8). 相似文献
109.
Daniel Carmona Joaquina Ferrer María Pilar Lamata Luis A. OroHans-Heinrich Limbach Gerd SchererJos Elguero María Luisa Jimeno 《Journal of organometallic chemistry》1994,470(1-2):271-274
The Arrhenius equation corresponding to the process P---Ag+P*---Ag*→---P---Ag*+P*---Ag has been determined for [(η6-p-cymene)Ru(μ-pz)3Ag(PPh3)] (1) by complete line-shape analysis of the 31P NMR spectra between −40°C and +30°C. It has the form K = 1011.8± e(−46±5 kJ mol−1/RT). The preexponential term, log A = 11.8 corresponds to a small activation entropy, whereas the activation energy, 46 kJ mol−1 is comparable to those determined for other phosphorus—metal compounds. 相似文献
110.