共查询到20条相似文献,搜索用时 0 毫秒
1.
The formation of cationic palladium(II)complexes [TrpyPdII]+X− by salt metathesis of the respective trifluoroacetates with different salts of weakly coordinating anions X− was investigated. With non-hydrolizable counterions, cationic mono- and dinuclear complexes are observed depending on the nature of the anion X− and the solvent. The mononuclear cations, which are only formed with X = BArF, most probably carry a weakly bound molecule of dichloromethane at the fourth coordination site of PdII. When treated with diazoalkanes, only these are sufficiently reactive to form carbene complexes. Four- and five coordinate Lewis base adducts [TrpyPdIIL]+ with L = CH3NC, tBuNH2, PMe3, PEt3 and PiPr3 and [TrpyPdIIL2]+ with L = PMe3 were prepared from the mononuclear cations [TrpyPdII]+BArF−. From structural studies it becomes apparent, that the formation of stable five coordinate PdII species is restricted to medium size ligands and depends on the delicate balance between the steric influence of L and the strain, which is induced on the TrpyPdII unit. 相似文献
2.
Debabrata Chatterjee Anannya Mitra Ayon Sengupta Susan Basak 《Inorganica chimica acta》2005,358(10):2900-2908
The interaction of [PdII(mida)(Cl)]− (1) (mida2− = N-methyliminodiacetate) and [PdII(pydc)(Cl)]− (2) (pydc2− = pyridyl-2,6-dicarboxylate) with adenosine-5′-monophosphate (AMP), inosine-5′-monophosphate (IMP) and glutathione (GSH) was studied kinetically as a function of [L] (L = AMP, IMP, GSH) and [Cl−] and temperatures (10-35 °C) at pH 4.0. The kinetic results suggest that the reaction of 1 and 2 with the 5′-nucleotides (AMP, IMP) is characterized by the hydrolysis of chloro-complexes followed by the aquo-substitution with purine based 5′-nucleotides through its N7 atom. The reaction of 1 and 2 with GSH takes place through the direct chloride replacement with GSH. Kinetic data and activation parameters are interpreted in terms of an associative mechanism and discussed in reference to the data reported earlier. The [PtII(mida)(Cl)]− (3) and [PtII(pydc)(Cl)]− (4) complexes were prepared and allowed to interact with AMP and IMP and their reaction products were characterized by 1H NMR studies. The antitumor activity of 3 and 4 was examined against MCF-7 (breast cancer), NCI-H460 (lung cancer) and SF-268 (CNS) cell lines. 相似文献
3.
Janet L Wedgwood Ann P Hunter Roman A Kresinski Andrew W.G Platt Bridget K Stein 《Inorganica chimica acta》1999,290(2):743-196
The reactions of the alkylsulfonated phosphines LM=Ph2P(CH2)nSO3Na/K (n=2, 3, 4) with K2PtCl4 and K2PdCl4 have been studied in homogeneous aqueous solution as a function of pH. In homogeneous acidic solution the protonated phosphines react to give cis- and trans-PtCl2(LH)2. The biphasic reaction between 1,5-cyclooctadiene platinum(II) chloride in dichloromethane and acidified aqueous LNa/K gives a higher proportion of the cis isomer. In neutral solution the initial reaction to give [PtCl(LNa/K)3]+Cl− is followed by slow formation of cis-PtCl2(LNa/K)2. K2PdCl4 reacts more rapidly to give PdCl2(LNa/K)2. In homogeneous alkaline solution rapid oxidation of the phosphine occurs with only small amounts of platinum complex being observable. The biphasic reaction yields phosphine oxide in the aqueous layer and a small amount of the chelate complexes PtL2 in the organic. Representative complexes have been isolated and characterised and the mechanisms for the reactions discussed. The electrospray mass spectra of solutions of the isolated complexes have been recorded in both positive and negative ionisation modes. The positive ionisation spectra are complicated, but platinum and palladium containing ions derived from loss of chloride, H+ and HCl are observed in the negative ionisation spectra. 相似文献
4.
Square planar diamidato-bis(phosphanyl) palladium(II) complexes have been prepared and characterized. Most products precipitate out of THF solution on reaction of the parent ligand with Pd(OAc)2 in the presence of 2 equiv. of base at 50 °C overnight. The solution and solid state structure of each complex is reported based on multinuclear NMR and X-ray analyses, respectively. The effects of carboxamido nitrogen coordination on the stabilization of the metal center from reduction were studied using cyclic voltammetry. The irreversible peak reduction potential of each complex was greater by approximately −340 mV to −590 mV as compared to Pd(PPh3)2Cl2 indicating that carboxamido nitrogen coordination protects the Pd(II) center from reduction. 相似文献
5.
Prasad P. Phadnis Thilo Schurr Falk Lissner Wolfgang Kaim 《Inorganica chimica acta》2005,358(9):2609-2617
Dinaphthylmethylarsine complexes of palladium(II) and platinum(II) with the formulae [MX2L2] (M = Pd, Pt; L = di(1-naphthyl)methylarsine = Nap2AsMe and X = Cl, Br, I), [M2Cl2(μ-Cl)2L2], [PdCl(S2CNEt2)L], [Pd2Cl2(μ-OAc)2L2] and [MCl2(PR3)L] (PR3 = PEt3, PPr3, PBu3, PMePh2) have been prepared. These complexes have been characterized by elemental analyses, IR, Raman, NMR (1H, 13C, 31P) and UV-vis spectroscopy. The stereochemistry of the complexes has been deduced from the spectroscopic data. The crystal structures of trans-[PdCl2(PEt3)(Nap2AsMe)] and of [Pd(S2CNEt2)2], a follow-up product, were determined. The UV-vis spectra of [MX2L2] complexes show a red shift on going from X = Cl to X = I. The complexes [PdX2L2] and [PtX2L2] are strongly luminescent in fluid solution and in the solid at ambient temperature. 相似文献
6.
A series of cationic palladium complexes [(4-Mebti)PdL]+ with 4-Mebti = anion of bis(4-methylthiazolylimino)isoindoline and L = neutral ligand with group 16 donor atom has been prepared from the chlorido derivative [(4-Mebti)PdCl] and NaBArF (BArF = tetrakis(3,5-bis(trifluoromethyl)phenyl)boranate) in the presence of the respective donor ligand. Crystallographic and spectroscopic analyses were achieved for species with L = SMe2, SeMe2, dmf, acetamide, diphenylurea, and formiate. The latter two complexes represent products from hydrolyses of phenyl isocyanate and dmf, respectively, which occur during the ligand exchange reactions. Several other O-donor ligands like thf, acetone, Me2O, water, and others are not bound to the palladium ion, and the dinuclear μ-chlorido derivative [{(4-Mebti)Pd}2Cl]+ is isolated in these cases instead. The crystallographic analyses prove the expected presence of distorted, pseudo-planar palladium chelates, and the degree of distortion correlates well with the chemical shifts observed for the proton nuclei of the terminal methyl groups in the 1H NMR experiment. 相似文献
7.
Seyyed Javad Sabounchei Sepideh Samiee Ali Naghipour 《Inorganica chimica acta》2010,363(14):3973-3980
The reaction of the non-symmetric phosphorus ylides, Ph2P(CH2)nPPh2C(H)C(O)PhR [Y1-Y4: n = 1, R = Cl, Br, NO2, OCH3 and Y5-Y8: n = 2, R = Cl, Br, NO, OCH3] with dichloro(1,5-cyclooctadiene)palladium(II) in dichloromethane under mild conditions afford the monomeric P-C chelated complexes, [(Y)PdCl2] (Y = Y1-Y8). These complexes were fully characterized by elemental analysis and spectroscopic techniques such as IR, 1H, 31P, and 13C NMR. In addition, the identity of complexes [(Y5)PdCl2] (1b) and [(Y8)PdCl2] (4b) was unequivocally determined by single crystal X-diffraction techniques, both structures consisting of six-membered rings formed by coordination of the ligands through the phosphine group and the ylidic carbon atom to the metal center. The coordination geometry around the Pd atoms in both these complexes be defined as slightly distorted square planar. Furthermore, their electrochemical behavior was also investigated by cyclic voltammeters, thus the cyclic voltammetry of complex [(Y1)PdCl2], in dichloromethane solution with Pt electrode, shows that the redox reaction of the pair Pd(II)/Pd(0) is irreversible with the cathodic peak potential at −1.08 V versus Ag wire. 相似文献
8.
Fulvenes (1a–e) derived from condensation of cyclopentadiene with acetone or a variety of aldehydes were treated with LiPAr2 (Ar = phenyl, p-tolyl) to yield the respective substituted (diarylphosphinomethyl)cyclopentadienides (2, 3). Subsequent reaction with ZrCl4(THF)2 gave the respective bis[(diarylphosphinomethy])cyclopentadienyl]zirconium dichlorides ( Ar = phenyl (4), p-tolyl (5)). The complex rac-[C5H4-CH(CH3)-PPh2]2ZrCl2 (rac-4b) was characterized by X-ray diffraction. The reaction of complexes 4a and 5a [(Cp-CMe2-PAr2)2ZrCl2] with PdCl2(NCPh)2 or PtCl2(NCPh)2 leads to the formation of the trans-(metallocene-chelate-phosphane)metal complexes 6–9 (e.g. trans-Cl2Pd(Ph2P-CMe2-Cp)2ZrCl2]. Chloride abstraction from the reaction product of [Cp-CH(CMe3)PPh2]2ZrCl2 with PdCl2(NCPh)2 eventually gave the cationic complex [meso,trans-(Cp-CH(CMe3)PPh2)2(Cl)Zr(μ-Cl)Pd(Cl)]+ (10) that was also characterized by X-ray diffraction. It features a dimetallabicyclic framework with two Cp-CHR-PPh2 ligands and a chloride bridging between the early and the late transition metal center. 相似文献
9.
Urszula Kalinowska Magdalena Ma?ecka Bernhard Lippert 《Inorganica chimica acta》2005,358(8):2464-2472
The synthesis of diethyl (pyridin-2-, -3-, -4-ylmethyl)phosphate (2-pmOpe, 3-pmOpe, 4-pmOpe) ligands and their palladium (II) complexes of general formula trans-[PdCl2L2] (L = 2-pmOpe, 3-pmOpe,4-pmOpe) has been described. Pyridine phosphate derivatives were synthesized via the condensation of phosphorochloridic acid diethyl ester with an appropriate pyridinylmethanol in the presence of triethylamine. The compounds have been identified and characterized by IR, far-IR, 1H NMR, 31P NMR, 31P CP-MAS NMR and elemental analyses. The crystal and molecular structures of palladium (II) complexes, i.e., [PdCl2(2-pmOpe)2] and [PdCl2(4-pmOpe)2] determined by the X-ray diffraction method, are presented. In both structures, Pd(II) ions are four-coordinated by two chlorine atoms and two pyridine nitrogen atoms. The geometry of complexes is square-planar and adopt a trans configuration, which is consistent with preparation method. 相似文献
10.
Julia Pushkar 《Inorganica chimica acta》2004,357(4):1295-1298
Treatment of a benzene solution of (tmeda)PdMe2 or (dppe)PdMe2 with carbon dioxide gives the corresponding methyl bicarbonate complex, (L-L)PdMe(O2COH). These were characterised by NMR spectroscopy and elemental analysis. Under strictly dry conditions no reaction was observed. Recrystallisation of the tmeda bicarbonate complex from acetone yields the corresponding η2-carbonate complex, which was characterised by X-ray crystallography. The reaction probably proceeds through attack by free carbonic acid on the dimethyl complex. 相似文献
11.
Nade?da B. Joki? Serena Li Min Goh Wolfgang A. Herrmann 《Inorganica chimica acta》2010,363(15):4181-4188
The synthesis and characterization of symmetrically substituted bis-N-heterocyclic carbene palladium(II) complexes with a functional group attached to the bridging moiety is described, as well as the immobilization of one of them on polystyrene Wang resin. The resulting complexes were tested both in homogeneous and heterogeneous Suzuki-Miyaura cross-coupling reactions. 相似文献
12.
The first [Pd(Ln)2(ox)] xH2O oxalato(ox) complexes involving 2-chloro-N6-(benzyl)-9-isopropyladenine (L1; complex 1), 2-chloro-N6-(4-methoxybenzyl)-9-isopropyladenine (L2; 2), 2-chloro-N6-(2,3-dimethoxybenzyl)-9-isopropyladenine (L3; 3), 2-chloro-N6-(2,4-dimethoxybenzyl)-9-isopropyladenine (L4; 4), and 2-chloro-N6-(4-methylbenzyl)-9-isopropyladenine (L5; 5) have been synthesized by the reactions of potassium bis(oxalato)palladate(II) dihydrate, [K2Pd(ox)2]·2H2O, with the mentioned organic compounds (H2ox = oxalic acid; x = 0 for 1-3 and 5 or 2 for 4). Elemental analyses (C, H, N), FTIR, Raman and NMR (1H, 13C, 15N) spectroscopies, conductivity measurements and thermal studies (thermogravimetric and differential thermal analyses, TG/DTA) have been used to characterize the prepared complexes. The molecular structures of [Pd(L2)2(ox)] (2) and [Pd(L5)2(ox)]·L5·Me2CO (5·L5·Me2CO) have been determined by a single crystal X-ray analysis. The geometry of these complexes is slightly distorted square-planar with two appropriate Ln (n = 2 or 5) molecules mutually arranged in the head-to-head (2) or head-to-tail (5) orientation. The Ln ligands are coordinated to the central Pd(II) ion via the N7 atoms. The same conclusions regarding the binding properties of L1-L5 ligands can be made based on multinuclear NMR spectra. In vitro cytotoxicity of the complexes 1-5 has been evaluated against human chronic myelogenous leukaemia (K562) and human breast adenocarcinoma (MCF7) cancer cell lines. Significant cytotoxicity has been determined for the complexes 3 (IC50 = 6.2 μM) and 5 (IC50 = 6.8 μM) on the MCF7 cell line, which is even better than that found for the well-known and widely-used platinum-bearing antineoplastic drugs, i.e. oxaliplatin and cisplatin. 相似文献
13.
The reactions of Ru(NH3)5py2+, Ru(NH3)4bpy2+, Ru2(NH3)10pz5+, RuRh(NH3)10pz5+ and Ru(NH3)5pz2+ with bromine are first-order in ruthenium and first-order in bromine. The rates decrease with increasing bromide ion concentration and, except for Ru(NH3)5pz2+, are independent of hydrogen ion concentration. The reactions are postulated to proceed via outer-sphere, one-electron transfer from Ru(II) to Br2 with the formation of Br2− as a reactive intermediate. The bromide inhibition is ascribed to the formation of Br3− which is unreactive in outer-sphere reactions because of the barrier imposed by the need to undergo reductive cleavage. The reaction of Ru(NH3)5pz2+ is inhibited by hydrogen ions. The hydrogen ion dependence shows that Ru(NH3)5pzH3+ has a pKa of 2.49 and is at least 500 times less reactive than Ru(NH3)5pz2+. The reaction of Ru2(NH3)10pz4+ with bromine is biphasic. The second phase has a rate identical to that of the Ru2(NH3)10pz5+-Br2 reaction. A detailed analysis shows that the reaction of Ru2(NH3)10pz4+ with bromine proceeds by a sequence of one-electron steps, Br2− being produced as an intermediate. A linear free energy relationship between rate constants and equilibrium constants, obeyed for all the reactions studied, provides an estimate of 1.5 × 102 M−1 s−1 for the self-exchange rate constant of the Br2/Br2− couple. 相似文献
14.
Keliang Pang 《Inorganica chimica acta》2009,362(12):4609-4615
Nickel and palladium paddlewheel complexes that feature 2-mercapto-1-t-butylimidazolyl (mimBut) bridging ligands, namely Ni2[mimBut]4 and Pd2[mimBut]4, have been synthesized and structurally characterized by X-ray diffraction. Since the mimBut ligand bridges in an asymmetric manner via a sulfur and nitrogen donor, paddlewheel compounds of the type M2[mimBut]4 may exist as isomers that are distinguished by the relative orientations of the ligands. In this regard, the (4,0)-Ni2[mimBut]4 and trans-(2,2)-Ni2[mimBut]4 isomers have been isolated for the nickel system, while the (4,0)-Pd2[mimBut]4 and (3,1)-Pd2[mimBut]4 isomers have been isolated for the palladium system. 相似文献
15.
The kinetics of substitution reactions of [η-CpFe(CO)3]PF6 with PPh3 in the presence of R-PyOs have been studied. For all the R-PyOs (R = 4-OMe, 4-Me, 3,4-(CH)4, 4-Ph, 3-Me, 2,3-(CH)4, 2,6-Me2, 2-Me), the reactions yeild the same product [η5-CpFe(CO)2PPh3]PF6, according to a second-order rate law that is first order in concentrations of [η5-CpFe(CO)3]PF6 and of R-PyO but zero order in PPh3 concentration. These results, along with the dependence of the reaction rate on the nature of R-PyO, are consistent with an associative mechanism. Activation parameters further support the bimmolecular nature of the reactions: ΔH≠ = 13.4 ± 0.4 kcal mol−1, ΔS≠ = −19.1 ± 1.3 cal k−1 mol−1 for 4-PhPyO; ΔH≠ = 12.3 ± 0.3 kcal mol−1, ΔS≠ = 24.7 ±1.0 cal K−1 mol−1 for 2-MePyO. For the various substituted pyridine N-oxides studied in this paper, the rates of reaction increase with the increasing electron-donating abilities of the substituents on the pyridine ring or N-oxide basicities, but decrease with increasing 17O chemical shifts of the N-oxides. Electronic and steric factors contributing to the reactivity of pyridine N-oxides have been quantitatively assessed. 相似文献
16.
Reactions of ligands 1-ethyl-5-methyl-3-phenyl-1H-pyrazole (L1) and 5-methyl-1-octyl-3-phenyl-1H-pyrazole (L2) with [PdCl2(CH3CN)2 and K2PtCl4 gave complexes trans-[MCl2(L)2] (L = L1, L2). The new complexes were characterised by elemental analyses, conductivity measurements, infrared, 1H and 13C{1H} NMR spectroscopies and X-ray diffraction. The NMR study of the complex [PdCl2(L1)2], in CDCl3 solution, is consistent with a very slow rotation of ligands around the Pd-N bond, so that two conformational isomers can be observed in solution (syn and anti). Different behaviour is observed for complexes [PdCl2(L2)2] and [PtCl2(L)2] (L = L1, L2), which present an isomer in solution at room temperature (anti). The crystal structure of [PdCl2(L1)2] complex is described, where the Pd(II) presents a square planar geometry with the ligands coordinated in a trans disposition. 相似文献
17.
The reaction of [Rh2(acam)4(H2O)2]ClO4 (1) (Hacam = acetamide) with K2PtCl4 in aqueous solution gave crystals of [Rh2(acam)4(H2O)2][Rh2(acam)4{(μ-Cl)2PtCl2}] · 2H2O (2). The reaction of 1 with K2PdCl4 produced the palladium analog [Rh2(acam)4(H2O)2][Rh2(acam)4{(μ-Cl)2PdCl2}] · 2H2O (3) and a small amount of an aquated palladium complex [Rh2(acam)4{(μ-Cl)2PdCl(H2O)}] · H2O (4). Complexes 2 and 3 have anionic chains of [Rh2(acam)4{(μ-Cl)2MCl2}]− (M = Pt, Pd), while 4 includes neutral chains of [Rh2(acam)4{(μ-Cl)2PdCl(H2O)}]. Although all of the structures include infinite chains of (-Rh-Rh-Cl-M-Cl-)n (M = Pt, Pd), the chain structures are different; zigzag for 2 and 3 and helical for 4. In the structures of 2 and 3, the counter cation [Rh2(acam)4(H2O)2]+ made a hydrogen-bonded chain with the crystallization water molecules. The cationic chains and the anionic chains are connected with hydrogen bonds. In the structure of 4, the chains are also linked together by direct hydrogen bonds between the chains and those with the crystallization water molecules. ESR spectra of the powdered samples of 2 and 3 at 77 K were consistent with a rhombic structure: for 2, g1 = 2.111, g2 = 2.054, g3 = 2.004; for 3, g1 = 2.115, g2 = 2.057, g3 = 2.007. These results indicate that there is a spin flip-flop exchange between the cations, [Rh2(acam)4(H2O)2]+, and the units in the anionic chains. The electrical conductivities of 2 and 3 were in the order of 10−7 S cm−1 at room temperature. 相似文献
18.
Michael W. Jones Robert M. Adlington Jack E. Baldwin Delphine D. Le Pevelen Nicolas Smiljanic 《Inorganica chimica acta》2010,363(6):1097-3600
Three new palladium(II) complexes incorporating the bispyrazolylmethane core have been synthesised and fully characterised in the solution and solid state. Single crystal X-ray studies revealed almost complete blocking of the upper face of the palladium ion by the substituents at the 3- and 5-positions of the pyrazole rings. Preliminary screening of the complexes for palladium(II) mediated catalysis revealed good catalytic activity for the Heck coupling reaction. 相似文献
19.
Petrović ZD Djuran MI Heinemann FW Rajković S Trifunović SR 《Bioorganic chemistry》2006,34(5):225-234
The reaction of PdCl2, or K2PdCl4, with diethanolamine (DEA), in the molar ratio 1:2, affords the trans-[PdCl2(DEA)2] complex. X-ray structure analysis of this complex confirmed the formation of the trans-isomer. The complex crystallizes in the space group P42bc. The central Pd(II) ion is coordinated in an almost ideal square-planar fashion with a small deformation of the Cl-Pd-Cl angle (175.6(7) degrees) due to N-H...Cl hydrogen bonding. The N-H group participates in a bifurcated interaction with the two symmetry related Cl- anions. The hydroxyl groups of the diethanolamine ligand form very strong hydrogen bonds between the complex units, thus leading to infinite zigzag (O-H...O-H...O-H..) chains in the crystal packing. The complex units are further connected by weaker intermolecular hydrogen bonds of the N-H...Cl type in a way to form layers parallel to the crystallographic (001) plane. The reaction between the trans-[PdCl2(DEA)2] or trans-[Pd(H2O)2(DEA)2]2+ complex and MeCOHis-Gly dipeptide at 1.5 < pH < 2.0 and at 25 degrees C leads to the regioselective cleavage of the amide bond involving the carboxylic group of the histidine. The cleavage of the substrate was fast and went almost to completion within less than one hour. 相似文献
20.
Diffusion NMR investigations were carried out in CD2Cl2 for a series of neutral (1-7) and cationic (8-10) square planar palladium complexes. Diffusion data were elaborated through a modified Stokes-Einstein equation that takes into account the size and shape of molecules. The hydrodynamic volume at infinite dilution of all complexes was found to be similar to the crystallographic volume and always much larger than the van der Waals volume. The self-aggregation tendency of [Pd(N,C−)(N,N)][PF6] ionic complexes [(N,C−) = (C6H4-(Ph)C(O)-CN-Et); 8, (N,N) = 2,2′-bipirydine; 9, (N,N) = (2,6-(iPr)2-C6H3)NC(Me)-C(Me)N(2,6-(iPr)2-C6H3); 10, (N,N) = (2,6-(iPr)2-C6H3)NC(R′)-C(R′)N(2,6-(iPr)2-C6H3), R′2 = naphthalene-1,8-diyl] was investigated by performing 1H and 19F diffusion experiments as a function of the concentration. Clear evidence for the formation of ion triples containing two cationic units was obtained for 8, most likely due to the establishment of a weak Pd?O interaction. The tendency to form ion triples was much reduced in 9 and 10, having an increased steric hindrance in the apical positions. While 9 showed the usual tendency to afford a mixture of free ions and ion pairs, solvated ions were the predominant species in the case of 10 even at high concentration values (approaching 100 mM). 相似文献