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1.
Three symmetric N,N-diarylformamidine dithiocarbamates, N,N′-bis(2,6-dimethylphenyl)formamidine dithiocarbamate (DTL1), N,N′-bis(2,6-disopropylphenyl)formamidine dithiocarbamate (DTL2) and N,N′-dimesitylformamidine dithiocarbamate (DTL3), and three unsymmetric ones, N′-(2,6-dichlorophenyl-N-(2,6-dimethylphenyl)formamidine dithiocarbamate (DTL4), N′-(2,6-dichlorophenyl)-N-(2,6-diisopropylphenyl)formamidine dithiocarbamate (DTL5) and N′-(2,6-dichlorophenyl)-N-mesitylformamidine dithiocarbamate (DLT6), were reacted with chloridocobalt(III) in water to give Co-(DTL1)3 ( 1 ), Co-(DTL2)3 ( 2 ), Co-(DTL3)3 ( 3 ), Co-(DTL4)3 ( 4 ), Co-(DTL5)3 ( 5 ) and Co-(DTL6)3 ( 6 ). All the dithiocarbamates and complexes were characterized using 1H NMR, 13C NMR, Fourier transform infrared, UV–visible and mass spectra and the purity confirmed by elemental analysis. In addition, crystal structures of complexes 1 , 2 , 4 and 5 were determined, confirming the formation of mononuclear species in which the Co(III) centers coordinated to six sulfur atoms from three dithiocarbamate ligands resulting in distorted octahedral geometries. All complexes showed moderate to good antibacterial activities against Gram-negative bacteria Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae and Pseudomonas aeruginosa even at low concentrations. None of the six were active against Gram-positive bacterium methicillin-resistant Staphylococcus aureus and only active against S. aureus at high concentrations. Complexes 5 and 6 were found to be more active than ciprofloxacin against S. typhimurium, E. coli, P. aeruginosa and K. pneumoniae and complexes with chloro-substituted ligands generally had enhanced activities. Antioxidant activities of the dithiocarbamate salts and their Co(III) complexes were also investigated using DPPH assay and the complexes were found to be more efficient. Complex 2 with an IC50 value of 2.84 × 10−4 mM displayed the highest activity of all compounds tested, even outdoing ascorbic acid. The radical scavenging ability of the complexes followed the order 2 > 1 > ascorbic acid > 3 > 4 > 6 > 5 . 相似文献
2.
Emily C. Monkcom Daniël de Bruin Annemiek J. de Vries Dr. Martin Lutz Dr. Shengfa Ye Prof. Dr. Robertus J. M. Klein Gebbink 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(16):5191-5204
We present the synthesis and coordination chemistry of a bulky, tripodal N,N,O ligand, ImPh2NNO t Bu ( L ), designed to model the 2-His-1-carboxylate facial triad (2H1C) by means of two imidazole groups and an anionic 2,4-di-tert-butyl-subtituted phenolate. Reacting K-L with MCl2 (M = Fe, Zn) affords the isostructural, tetrahedral non-heme complexes [Fe(L)(Cl)] ( 1 ) and [Zn(L)(Cl)] ( 2 ) in high yield. The tridentate N,N,O ligand coordination observed in their X-ray crystal structures remains intact and well-defined in MeCN and CH2Cl2 solution. Reacting 2 with NaSPh affords a tetrahedral zinc thiolate complex, [Zn(L)(SPh)] ( 4 ), that is relevant to isopenicillin N synthase (IPNS) biomimicry. Cyclic voltammetry studies demonstrate the ligand's redox non-innocence, where phenolate oxidation is the first electrochemical response observed in K-L , 2 and 4 . However, the first electrochemical oxidation in 1 is iron-centred, the assignment of which is supported by DFT calculations. Overall, ImPh2NNO t Bu provides access to well-defined mononuclear, monoligated, N,N,O-bound metal complexes, enabling more accurate structural modelling of the 2H1C to be achieved. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(14):2307-2314
Copper(I) complexes with a sterically hindered thiourea, [Cu(dchtu)2X] (dchtu = N,N′-dicyclohexylthiourea; X=Cl 1, Br 2), were synthesized and their crystal structures were determined. Compounds 1 and 2 are isostructural orthorhombic, space group P212121. Crystallographic data for 1 : a = 13.1711(13), b = 14.2610(19), c = 15.793(2) Å, V = 2966.4(6) Å3, Z = 4. For 2 : a = 13.2628(13), b = 14.3410(19), c = 15.860(2) Å, V = 3016.5(6) Å3, Z = 4. The stoichiometry of CuX complexes with thiourea is influenced by substituents on the nitrogens. Copper(I) halides only form bis-adducts with the sterically hindered dchtu ligand even with molar excesses of dchtu due to steric hinderance of the cyclohexyl substituents. In 1 and 2, the Cu(I) is trigonally coordinated by the sulfur atoms of two monodentate N,N′-dicyclohexylthiourea ligands and one halide. The structures of the complexes are stabilized by a system of intermolecular H-bonding. 相似文献
4.
Bin Ma Chun‐Fu Wu Jing‐Yu Yang Rui Wang Yoshihiro Kano Dan Yuan 《Helvetica chimica acta》2009,92(8):1575-1585
Three new alkaloids, 2′‐O‐β‐D ‐glucopyranosyl‐11‐hydroxyvincoside lactam ( 1 ), 22‐O‐demethyl‐22‐O‐β‐D ‐glucopyranosylisocorynoxeine ( 2 ), and (4S)‐corynoxeine N‐oxide ( 3 ) were isolated from the leaves of Uncaria rhynchophylla, together with four known tetracyclic oxindole or indole alkaloids, isocorynoxeine N‐oxide ( 4 ), rhynchophylline N‐oxide ( 5 ), isorhynchophylline N‐oxide ( 6 ), and dihydrocorynantheine ( 7 ), and an indole alkaloid glycoside, strictosidine ( 8 ). The structures of 1 – 3 were elucidated by spectroscopic methods including UV, IR, ESI‐TOF‐MS, 1D‐ and 2D‐NMR, as well as CD experiments. The activity assay showed that 8 (IC50=8.3 μM ) exhibited potent inhibitory activity on lipopolysaccharide(LPS)‐induced nitrogen monoxide (NO) release in N9 microglia cells. However, only weak inhibitory activities were observed for 1 – 7 (IC50>100 μM for 1 – 6 or >30 μM for 7 ). 相似文献
5.
A new series of hexa‐coordinated stable Ru(III) Schiff base complexes of the type [RuX(EPh3)(L)] (where X = Cl/Br; E = P/As; L = tetradentate N2O2 donor Schiff ligands) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurement, FT‐IR, UV–vis, 13C{1H}‐NMR, ESR spectra, electrochemical and powder X‐ray diffraction pattern studies. The selective oxidation of alcohols to their corresponding carbonyl compounds occurred in the presence of N‐methylmorpholin‐N‐oxide (NMO), H2O2 and O2 atmosphere at ambient temperature as co‐oxidants and C? C coupling reactions. Further, these new Schiff base ligands and their Ru(III) complexes were also screened for their antibacterial activity against K. pneumoniae, Shigella sp., M. luteus, E. coli and S. typhi. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
6.
Heteropentanuclear Oxalato‐Bridged nd–4f (n=4, 5) Metal Complexes with NO Ligand: Synthesis,Crystal Structures,Aqueous Stability and Antiproliferative Activity
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Dr. Paul‐Steffen Kuhn B. Sc. Laura Cremer Dr. Anatolie Gavriluta Dr. Katarina K. Jovanović Dr. Lana Filipović Dr. Alfred A. Hummer Dr. Gabriel E. Büchel Dr. Biljana P. Dojčinović Dr. Samuel M. Meier Prof. Dr. Annette Rompel Dr. Siniša Radulović Dr. Jean Bernard Tommasino Dr. Dominique Luneau Prof. Dr. Vladimir B. Arion 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13703-13713
A series of heteropentanuclear oxalate‐bridged Ru(NO)‐Ln (4d–4f) metal complexes of the general formula (nBu4N)5[Ln{RuCl3(μ‐ox)(NO)}4], where Ln=Y ( 2 ), Gd ( 3 ), Tb ( 4 ), Dy ( 5 ) and ox=oxalate anion, were obtained by treatment of (nBu4N)2[RuCl3(ox)(NO)] ( 1 ) with the respective lanthanide salt in 4:1 molar ratio. The compounds were characterized by elemental analysis, IR spectroscopy, electrospray ionization (ESI) mass spectrometry, while 1 , 2 , and 5 were in addition analyzed by X‐ray crystallography, 1 by Ru K‐edge XAS and 1 and 2 by 13C NMR spectroscopy. X‐ray diffraction showed that in 2 and 5 four complex anions [RuCl3(ox)(NO)]2? are coordinated to YIII and DyIII, respectively, with formation of [Ln{RuCl3(μ‐ox)(NO)}4]5? (Ln=Y, Dy). While YIII is eight‐coordinate in 2 , DyIII is nine‐coordinate in 5 , with an additional coordination of an EtOH molecule. The negative charge is counterbalanced by five nBu4N+ ions present in the crystal structure. The stability of complexes 2 and 5 in aqueous medium was monitored by UV/Vis spectroscopy. The antiproliferative activity of ruthenium‐lanthanide complexes 2 – 5 were assayed in two human cancer cell lines (HeLa and A549) and in a noncancerous cell line (MRC‐5) and compared with those obtained for the previously reported Os(NO)‐Ln (5d–4f) analogues (nBu4N)5[Ln{OsCl3(ox)(NO)}4] (Ln=Y ( 6 ), Gd ( 7 ), Tb ( 8 ), Dy ( 9 )). Complexes 2 – 5 were found to be slightly more active than 1 in inhibiting the proliferation of HeLa and A549 cells, and significantly more cytotoxic than 5d–4f metal complexes 6 – 9 in terms of IC50 values. The highest antiproliferative activity with IC50 values of 20.0 and 22.4 μM was found for 4 in HeLa and A549 cell lines, respectively. These cytotoxicity results are in accord with the presented ICP‐MS data, indicating five‐ to eightfold greater accumulation of ruthenium versus osmium in human A549 cancer cells. 相似文献
7.
Zub V. Ya. Bugaeva P. V. Strizhakova N. G. Maletin Yu. A. 《Russian Journal of Coordination Chemistry》2004,30(10):747-752
The [M(HL)2(H2O)2]X2 complexes were synthesized (M = Mn(II), Co(II), Ni(II), Cu(II), Zn; X = CH3COO–, Cl–, BF4
–) that incorporate bidentately coordinated molecules of N,N-dimethylhydrazide of 4-nitrobenzoic acid (HL). The latter molecules chelate the metal atom through the carbonyl O atom and the N atom of dimethylamino group. The square-planar complexes of Cu and Ni with deprotonated form of a ligand with composition ML2 were also isolated. The synthesized complexes were studied by IR, electronic and EPR spectroscopies, and by cyclic voltammetry. 相似文献
8.
Chien Thang Pham Thu Ha Nguyen Thi Nguyet Trieu Kenji Matsumoto Hung Huy Nguyen 《无机化学与普通化学杂志》2019,645(17):1072-1078
The bifunctional ligand 2,6‐dipicolinoylbis(N,N‐diethylthiourea) (H2L) readily reacts with mixtures of Zn(CH3COO)2 and LnCl3 in MeOH at ambient temperature with formation of trinuclear heterobimetallic complexes [Zn2Ln(L)2(OAc)3] ( 1a – 1f ) (Ln = Ce, Nd, Sm, Gd, Dy, Er). The X‐ray single‐crystal diffraction and structural studies of the complexes revealed their isostructural nature, in which two doubly‐charged ligands {L2–} bind two Zn2+ ions with the terminal acylthiourea sites and one Ln3+ ion with the central 2,6‐pyridinedicarboxamide site. In the complexes, the coordination numbers of LnIII and ZnII ions are 9 and 5, respectively. Magnetic properties of the complexes were studied by temperature‐dependent dc magnetic measurements. The observed μeff values at room temperature are all closed to the calculated values. Fitting χM and M data of [Zn2Gd(L)2(OAc)3] ( 1d ) shows a giso value of 1.94. 相似文献
9.
Huapeng Liu Yaguo Gong Taofeng Zhang Na Li Quanyi Zhao Yonglin Chen Bin Liu Yawen Zheng 《中国化学》2015,33(7):739-748
A series of CO‐releasing molecules [M(CO)5L] (M=Cr, W, Mo, L=acetyl salicylamide 3‐pyridine, 1 – 3 ; L=N,N‐dimethyl‐4‐pyridine, 4 – 6 ; L=nicotinamide, 7 – 9 ; L=4‐CHO‐pyridine, 10 – 12 ) were synthesized. And in this paper, we have investigated mainly cytotoxicity and properties of the CO‐releasing molecules containing acetyl salicyamide‐3‐pyridine, namely complexes 1 – 3 . The stability of complexes 1 and 2 was evaluated by means of UV‐Vis spectroscopy and 1H NMR spectra. The results indicate complexes 1 and 2 were stable in methanol and acidic aqueous solution, but unstable and decayed in basic media (pH 10.0). Among all the complexes, complex 2 was the slowest CO‐releaser, and its half‐life was 73.8 min. Complex 9 containing nicotinamide was the fastest CO‐releaser with half‐life only 6.5 min. In addition, cytotoxic effects of all the complexes on the proliferation of fibroblast line were assayed by MTT. Among all the complexes, the IC50 of complex 1 was 6 µmol/L, revealing complex 1 possessed stronger antiproliferative activity than the control. Analysis by Flow cytometry revealed that complex 1 arrested Hela cells in S phase while complexes 2 and 8 arrested in G2/M phase. Cell apoptosis caused by the complexes mainly occurred in "Late apoptosis". 相似文献
10.
Sophie Putzien Stefan Wirth J. Nicolas Roedel Ingo‐Peter Lorenz Prof. Dr. 《无机化学与普通化学杂志》2009,635(8):1100-1105
The synthesis and molecular structure of trans‐{bis[(acetato‐κO)‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) ( 4 ) and cis‐{bis[chlorido‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) ( 5 ) is reported. Both neutral chelate complexes are prepared from the corresponding CoII salt [CoX2; X = OAc ( 1 ), Cl ( 2 )] and 2‐(1‐aziridinyl)ethanol (azolH, 3 ) in dry dichloromethane. A third, ionic complex, cis‐{bis[aqua‐(2‐(1‐aziridinyl)ethanol‐κ2N,O)]}cobalt(II) diacetate ( 6 ) is formed from 4 in the presence of water and could be crystallized from aqueous dichloromethane. In all cases, 2‐(1‐aziridinyl)ethanol is coordinating as bidentate chelate ligand by the nitrogen and oxygen atom of the aziridinyl and hydroxy moiety. After purification, the compounds have been fully characterized using IR spectroscopy and FAB+‐MS. The single‐crystal X‐ray structure analysis revealed a distorted octahedral geometry for all complexes with either trans ( 4 ) or cis ( 5 , 6 ) configuration. 相似文献
11.
《Journal of Coordination Chemistry》2012,65(14):2146-2164
AbstractA new series of tricarbonyl complexes of rhenium(I) in the “2 + 1” system with the bidentate ligand N,6-dimethylpyridine-2-carbothioamide ((CH3)NC5H4-CS-NH-CH3, MeLH(Me)NS) and a monodentate ligand (halides Cl, Br, or I, and the pseudohalide NCS anion) was synthesized. The use of mixed ligands led to the formation of neutral tricarbonylrhenium(I) complexes [Re(CO)3(MeLH(Me)NS)X] (X = Cl, Br, I, NCS) (1–4). Single-crystal X-ray diffraction was used to determine the crystal structures of all four compounds and those results were compared with molecular structures obtained from DFT calculations using the PBE0/def2-TZVPD approach. The complexes were also characterized by spectroscopic (FT-IR, NMR, and UV–vis) and analytical (HPLC, TGA, EA, ESI-MS) techniques. IR and UV–vis spectra were also calculated by DFT and TD-DFT methods. The cytotoxicity of these complexes was estimated using human ovarian cancer cell lines (A2780 and A2780cis), cervical cancer cells (HeLa), and non-cancerous human embryonic kidney cells (Hek-293). The toxicity of most complexes was moderate or low toward cancer cell lines (IC50 = 46–231 μM) and similar against non-cancerous cells (IC50 = 41-121 μM). Only the complex with chlorido ligand remarkably inhibited growth of ovarian cancer cells (IC50 = 3 and 12 μM for A2780 and A2780cis, respectively). The cytotoxicity of 1 was higher than that of cisplatin. 相似文献
12.
Ryan J. Andrews Prof. Douglas W. Stephan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(32):7194-7198
B(C6F5)3 undergoes nucleophilic attack by N,N′-dimesityldiamidocarbene (DAC) with fluoride transfer to the boron center, resulting in a new zwitterion ( 1 ). This B−F fluoride can be replaced or abstracted to give the corresponding hydride ( 2 ) or triflate ( 3 ) derivatives or the corresponding cation ( 4 ). These species are reduced with KC8 or Cp2Co to give isolable anionic and neutral radicals ( 5 – 8 ). Similarly, the [Ph3C] cation undergoes nucleophilic attack by DAC resulting in the spontaneous formation of the radical cation ( 9 ). 相似文献
13.
Zdenk Trvní
ek Pavel tarha Michal ajan Zdenk Dvok 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(3):248-254
A new electroneutral half‐sandwich tantalum(V) dichlorido complex containing pentamethylcyclopentadienyl (Cp*) and the double‐deprotonated version of the Schiff base 2‐ethoxy‐6‐{(E)‐[(2‐hydroxyphenyl)imino]methyl}phenol (H2L) as ligands, namely cis‐dichlorido(2‐ethoxy‐6‐{(E)‐[(2‐oxidophenyl)imino]methyl}phenolato‐κ3O,N,O′)(η5‐pentamethylcyclopentadienyl)tantalum(V), [Ta(C10H15)(C15H13NO3)Cl2] or [Ta(η5‐Cp*)(L)Cl2], has been prepared and thoroughly characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry, density functional theory (DFT) calculations and single‐crystal X‐ray diffraction. The molecular structure revealed that the TaV centre is coordinated by a η5‐Cp* ligand, two monodentate chlorido ligands and one O,N,O′‐tridentate L2? ligand. The crystal structure is stabilized by C—H…C, C—H…Cl and C…C intermolecular interactions. Moreover, the complex shows notable in vitro cytotoxicity against the A2780 human ovarian carcinoma cell line, with IC50 = 14.4 µM, which is higher than that of the conventional platinum‐based anticancer drug cisplatin (IC50 = 20.1 µM). 相似文献
14.
New hexa‐coordinated binuclear Ru(III) Schiff base complexes of the type {[(B)2X2Ru]2L} (where B = PPh3 or AsPh3; X = Cl or Br; L = binucleating N2O2 Schiff bases) were synthesized and characterized by elemental analysis, magnetic susceptibility measurement, FT‐IR, UV–vis, 13C{1H}‐NMR, ESR at 300 and 77 K, cyclic voltammetric technique, powder X‐ray diffraction pattern and SEM. The new complexes were used as catalysts in phenyl–phenyl coupling reaction and the oxidation of alcohols to their corresponding carbonyl compounds using molecular oxygen atmosphere at room temperature. Further, the new Schiff base ligands and their Ru(III) complexes were also screened for their antibacterial activity against K. pneumoniae, Shigella sp., M. luteus, E. coli and S. typhi. From this study, it was found that the activity of the ruthenium(III) Schiff base complexes almost reaches the effectiveness of the conventional bacteriocide standards. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
Adam Neuba Dr. Sonja Herres‐Pawlis Oliver Seewald Janna Börner Andreas J. Heuwing Ulrich Flörke Prof. Dr. Gerald Henkel 《无机化学与普通化学杂志》2010,636(15):2641-2649
The transition metal complexes with the ligand 1,3‐bis(N,N,N′,N′‐tetramethylguanidino)propane (btmgp), [Mn(btmgp)Br2] ( 1 ), [Co(btmgp)Cl2] ( 2 ), [Ni(btmgp)I2] ( 3 ), [Zn(btmgp)Cl2] ( 4 ), [Zn(btmgp)(O2CCH3)2] ( 5 ), [Cd(btmgp)Cl2] ( 6 ), [Hg(btmgp)Cl2] ( 7 ) and [Ag2(btmgp)2][ClO4]2·2MeCN ( 8 ), were prepared and characterised for the first time. The stoichiometric reaction of the corresponding water‐free metal salts with the ligand btmgp in dry MeCN or THF resulted in the straightforward formation of the mononuclear complexes 1 – 7 and the binuclear complex 8 . In complexes with MII the metal ion shows a distorted tetrahedral coordination whereas in 8 , the coordination of the MI ion is almost linear. The coordination behavior of btmgp and resulting structural parameters of the corresponding complexes were discussed in an comparative approach together with already described complexes of btmgp and the bisguanidine ligand N1,N2‐bis(1,3‐dimethylimidazolidin‐2‐ylidene)‐ethane‐1,2‐diamine (DMEG2e), respectively. 相似文献
16.
《Journal of Coordination Chemistry》2012,65(16):1807-1811
The complexes [M(CO)4(η2-H2L)] [M?=?Cr; 1, Mo; 2, W; 3] have been synthesized by photochemical reactions of VIB metal carbonyls [M(CO)6] [M?=?Cr,?Mo,?W] with N,N′-bis(salicylidene)-1,2-bis-(o-aminophenoxy)ethane (H2L) in THF and characterized by elemental analyses, FTIR, 1H?NMR and mass spectra. The H2L ligand is coordinated to the central metal as a bidentate ligand via the central azomethine nitrogen atoms in 1–3. 相似文献
17.
Using the ligands N‐methylimidazole ( MeIm ), N‐ethylimidazole ( EtIm ), N‐propylimidazole ( PrIm ), and 1‐methyl‐1H‐1, 2, 4‐triazole ( MeTz ) three series with a total of 13 iron(II) complexes were isolated. The series comprise of the following complexes: (a) [Fe( MeIm )6](ClO4)2 ( 1 ), [Fe( EtIm )6](ClO4)2 ( 2 ), [Fe( PrIm )6](ClO4)2( 3 ), [Fe( MeTz )6](ClO4)2 ( 4 ), [Fe( MeIm )6](MeSO3)2 ( 5 ), [Fe( EtIm )6](MeSO3)2 ( 6 ), and [Fe( MeTz )6](BF4)2 ( 10 ); (b) [Fe( MeIm )4(MeSO3)2]( 7 ), [Fe( EtIm )4(MeSO3)2] ( 8 ), and [Fe( PrIm )4(MeSO3)2] ( 9 ); (c) [Fe( MeIm )4(NCS)2] ( 15 ), [Fe( EtIm )4(NCS)2] ( 16 ), and [Fe( MeTz )4(NCS)2] ( 17 ). Single crystal X‐ray diffraction studies were performed on 7 – 10 and 15 – 17 . Temperature dependent magnetic susceptibility measurements were performed on selective examples of all series, and confirmed them to be in the HS state over the range 6–300 K. DFT calculations were performed at BP86/def‐SV(P) and TPSSh/def2‐TZVPP level on all [Fe L 6]2+ complex cations and the neutral complexes 7 – 9 and 15 – 17 . Additionally the four homoleptic nickel(II) complexes [Ni L 6](ClO4)2 ( 11 : L = MeIm ; 12 : L = EtIm ; 13 : L = PrIm ; 14 : L = MeTz ) were synthesized and compounds 11 – 13 structurally characterized. UV/Vis/NIR spectroscopic measurements were carried out on all homoleptic iron(II) and nickel(II) complexes. The 10Dq values were determined to be in the range of 11547–11574 and 10471–10834 cm–1 for the iron(II) and nickel(II) complexes, respectively. 相似文献
18.
Francisco Juliá‐Hernández Prof. Dr. Aurelia Arcas Prof. Dr. José Vicente 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(25):7780-7786
The complex [Pd(O,N,C‐L)(OAc)], in which L is a monoanionic pincer ligand derived from 2,6‐diacetylpyridine, reacts with 2‐iodobenzoic acid at room temperature to afford the very stable pair of PdIV complexes (OC‐6‐54)‐ and (OC‐6‐26)‐[Pd(O,N,C‐L)(O,C‐C6H4CO2‐2)I] (1.5:1 molar ratio, at ?55 °C). These complexes and the PdII species [Pd(O,N,C‐L)(OX)] and [Pd(O,N,C‐L′)(NCMe)]ClO4, (X=MeC(O) or ClO3, L′=another monoanionic pincer ligand derived from 2,6‐diacetylpyridine), are precatalysts for the arylation of CH2?CHR (R?CO2Me, CO2Et, Ph) using IC6H4CO2H‐2 and AgClO4. These catalytic reactions have been studied and a tentative mechanism is proposed. The presence of two PdIV complexes was detected by ESI(+)‐MS during the catalytic process. All the data obtained strongly support a PdII/PdIV catalytic cycle. 相似文献
19.
《应用有机金属化学》2017,31(10)
A series of symmetrically n ‐alkyl‐substituted mono benzimidazolium salts with steady increase in n ‐alkyl chain length have been prepared by stepwise N ‐alkylation resulting in salts ( 1 – 8 ). The mono N‐heterocyclic carbene (NHC)–Ag(I) complexes ( 9 – 16 ) derived from the respective salts were readily accessible by in situ deprotonation using Ag2O. All the salts and the complexes were characterized using Fourier transform infrared, 1H NMR, 13C NMR and elemental analyses. Furthermore, the structures of salts 3 and 7 and complex 16 were elucidated using X‐ray crystallography, which established that this mono NHC–Ag(I) complex has a linear bis‐carbene arrangement (C2–Ag). The proligands and the respective Ag(I) complexes were studied for their in vitro anticancer potential against human colon cancer cell line (HCT‐116) using 5‐fluorouracil as a standard. From the IC50 values of all the tested compounds, it can be postulated that there is an influential relationship between the increase in chain length of the wingtip n ‐alkyl groups and the anticancer potential. The proligands 4 – 8 and their respective complexes 12 – 16 with long n ‐alkyl chain lengths (n = 6–10) showed better IC50 values (0.3–3.9 μM) than the standard drug with the complexes displaying markedly better antiproliferation activity against HCT‐116 cell line than the respective proligands and the standard drug (IC50 = 10.2 μM). 相似文献
20.
Reaction of CuI with 1 or 2 equivalent(s) N,N′‐Bis(diphenylphosphino)‐2,6‐diaminopyridine (BDDP) gives two different complexes, [Cu(I)μ‐(BDDP‐κP,Npy)]2 ( 1 ) and [Cu(BDDP‐κP,Npy)2]I ( 2 ), in high yields. The determination of the molecular structure show that both CuI atoms are tetrahedrally coordinated, rather than a square‐planar geometry reported for Cr0, NiII‐BDDP complexes before, which contains a planar tridentate chelate ring system. The introduction of AuCl(tht) (tht = tetrahydrothiophene) into [Cu(BDDP‐κP,Npy)2]I leads unexpectedly to the formation of a digold complex 2,6‐[(ClAuPh2P)HN]2C5H3N and dimeric [Cu(I)μ‐(BDDP‐κP,Npy)]2. 相似文献