共查询到20条相似文献,搜索用时 15 毫秒
1.
Ilya I. Moiseev Rimma I. Rudy Natalia V. Cherkashina Lev K. Shubochkin Dmitri I. Kochubey Boris N. Novgorodov Galina A. Kryukova Vsevolod N. Kolomiychuk Michael N. Vargaftik 《Inorganica chimica acta》1998,280(1-2):339-347
It was found that the reduction of Pt(II), Pt(III) and Pt(I,III) acetates with H2 in the presence of 1,10-phenanthroline (phen), according to the standard procedure for the synthesis of palladium-561 giant clusters, resulted, unexpectedly, in the high-nuclear Pt(I) complex of the empirical composition Pt8phen3(OAc)4(OH)4(H2O)6 instead of the expected platinum colloid. Data of electron microscopy (TEM, HREM), small-angle X-ray scattering (SAXS), EXAFS and thermal analysis (DTA-TG) combined with elemental microanalysis all point to a loose structure of the obtained complex, with a minor Pt---Pt bonding (average coordination number for the Pt---Pt bonds is about 1). Variation of the preparation procedure resulted in a series of polymeric phen-platinum complexes, containing Pt atoms in oxidation states ranging from (+1) to (+0.3), and whose main structural features were established by the above-mentioned techniques. Giant clusters with dense Pt/PtOx cores (coordination number for the Pt---Pt bonds is about 6) were obtained by gradual heating of the precursor Pt complex to about 200°C as well as by a modified preparation procedure at 20°C. 相似文献
2.
The metal-based drugs represented by cisplatin, carboplatin, and oxaliplatin, prevail in cancer treatment, whereas new therapeutics are extremely slow to step into the clinic. Poor pharmacokinetics, multidrug resistance, and severe side effects greatly limit the development of metal-based anticancer drugs. The robustness and modular composition of supramolecular coordination complexes allow for the incorporation of novel diagnostic and therapeutic modalities, showing promising potentials for precise cancer theranostics. In this mini review, we highlight the recent advances in the development of supramolecular coordination complexes as diagnostic and therapeutic agents. The key focuses of these reports lie in searching sophisticated coordination ligands and nanoformulations that can potentially solve the issues faced by current metal-based drugs including imaging, resistance, toxicity, and pharmacological deficiencies. 相似文献
3.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):445-449
A new series of macrocyclic complexes of type [M(TML)X]X2, where M = Cr(III), Fe(III), TML is tetradentate macrocyclic ligand, and X = Cl?, NO3?, CH3COO?, have been synthesized by condensation of isatin and ethylenediamine in the presence of metal salt. The complexes were synthesized by both conventional and microwave methods. The complexes have been characterized with the help of elemental analysis, conductance measurement, magnetic measurement, and infrared, far infrared, and electronic spectral studies. Molar conductance values indicate them to be 1:2 electrolytes. Electronic spectra along with magnetic moments suggest five-coordinate square pyramidal geometry for these complexes. The complexes were also tested for their in vitro antibacterial activity. Some of the complexes showed satisfactory antibacterial activitiy. 相似文献
4.
Bim Graham Peter Comba Milton T. W. Hearn Leone Spiccia 《Journal of biological inorganic chemistry》2007,12(1):11-21
In this study, two different experimental approaches have been employed to examine the binding behavior of histidine-containing
peptides with metal ion complexes derived from the macrocyclic ligand 1,4,7-triazacyclononane (tacn). Firstly, a molecular
modeling approach has been employed to derive the strain energies for test peptide sequences that have a predicted propensity
to readily adopt an α-helical conformation. To this end, binuclear metal complexes were examined with peptides containing
two histidine residues in different locations in a pair of peptides of the same composition but different sequence. These
modeling results indicate that there are no energetic constraints for two-point binding to occur with dicopper(II) binuclear
complexes when two histidine residues are appropriately placed in an α-helical conformation. Secondly, binding experiments
were carried out to establish the effect of one or more histidine residues within a peptide sequence on the affinity of a
peptide for these Cu(II)–tacn derived binuclear complexes when immobilized onto a chromatographic support material. The results
confirm that for all chelating systems, higher affinity is achieved as the histidine number in the peptide structure increases,
although the relative location of the histidine residues in these small peptides did not introduce a significant constraint
to the conformation on interacting with the immobilized Cu(II) binuclear complexes. 相似文献
5.
Synthesis of a novel pyridine-diamino bridged diphosphine ligand and its macrocyclic metal complexes
A novel long chain diphosphine ligand with a pyridine-diamino bridge, 2,6-bis(N-benzyl-N-diphenylphosphinomethylamino)pyridine (PNP1), was prepared conveniently using the Mannich reaction of HPPh2 with paraformaldehyde and 2,6-bis(N-benzylamino)pyridine in high yield. Reactions of the ligand with metal complexes, M(COD)Cl2 (M = Pd, Pt), M(CH3CN)4ClO4 (M = Cu, Ag) and M(CO)6 (M = Mo, W) afforded the corresponding 10-numbered monometallic macrocyclic complexes with an uncoordinated pyridyl bridge. The monometallic chelate PdCl2(PNP1) continued to react with Ag+ or Cu+ giving the μ-Cl bridged bicyclic metallic complex (μ-Cl)2[PdCl(PNP1)]2. The diphenylphosphine group coordinated with metal ion in cis-form in all the 10-numbered macrocyclic metal complexes. Ligand PNP1 and another known analogous 2,6-bis(N-diphenylphosphinoamino)pyridine (PNP2) reacted with Au(SMe2)Cl giving the corresponding bimetallic Au2Cl2(PNP1) and Au2Cl2(PNP2), respectively. The latter bimetallic complexes continued to react with Ag+ and diphosphine ligand to give the corresponding bimetallic macrocyclic complexes Au2(ligand)2(ClO4)2. All the complexes were characterized and the structures of some complexes were confirmed by X-ray single crystallography determination. 相似文献
6.
The technique of calculating the strain energy of metal ion complexes as a function of metal to ligand bond length (Hancock and McDougall, J. Am. Chem. Soc., 102 (1980) 6553) is used to study best-fit sizes of metal ions for coordinating with tetraaza and triaza macrocyles. In addition to varying the metal to ligand bond length in the calculations, different coordination geometries of the metal ion are also examined. The metal to nitrogen (M-N) bond lengths, and coordination geometries, that give lowest energies for several N-donor macrocyles, are calculated by molecular mechanics, and 16-aneN4 (1,5,9,13-tetraazacyclohexadecane) is found, contrary to popular belief, to coordinate best with very small metal ions, with lowest energy occurring for a slightly flattened tetrahedral metal ion of M-N length = 1.81 Å. The best-fit size and geometry for coordination in 12-aneN4 (1,4,7,10-tetraazacyclotetradecane) is an M-N length of 2.15 Å and square pyramidal geometry, and with cyclam (1,4,8,11-tetraazacyclotetradecane) an M-N length of 2.06 Å and planar coordination that is approximately square. 相似文献
7.
Alla B. Antonova Alfred A. Johansson Nina A. Deykhina Allan G. Ginzburg Evgeny D. Korniyets Svetlana V. Kovalenko Nina I. Pavlenko Pavel V. Petrovskii Anatoly I. Rubaylo Irina A. Sukhina 《Inorganica chimica acta》1995,230(1-2):97-104
The dimetal μ-vinylidene complexes Cp(CO)2MnPt(μ-C = CHPh)L2 (L = tert.-phosphine or -phosphite), which have been obtained by coupling of the mononuclear complex Cp(CO)2Mn=C=CHPh and unsaturated PtL2 unit, add smoothly the Fe(CO)4 moiety to produce trimetal MnFePt compounds. The μ3-vinylidene cluster CpMnFePt(μ3-C=CHPh)(CO)6(PPh3) was prepared in quantitative yields from the reactions of Cp(CO)2MnPt(μ-C=CHPh)(PPh3)L (L = PPh3 or CO) with Fe2(CO)9 in benzene at 20 °C. The phosphite-substituted complexes Cp(CO)2Mnpt(μ-C=CHPh)L2 (L = P(OEt)3 or P(OPri)3) react under analogous conditions with Fe2(CO)9 to give mixtures (2:3) of the penta- and hexacarbonyl clusters, CpMnFePt(μ3-C = CHPh)(CO)5L2 and CpMnFePt(μ3-C = CHPh)(CO)6L, respectively. The similar reaction of the dimetal complex Cp(CO)2MnPt(μ-C = CHPh)(dppm), in which the Pt atom is chelated by dppm = Ph2PCH2PPhPin2 ligand, gives only a 15% yield of the analogous trimetal μ3-vinylidene hexacarbonyl product CpMnFePt(μ3-C = CHPh)(CO)(dppm), but the major product (40%) is the tetranuclear μ4-vinylidene cluster (dppm)PtFe3(μ4-C = CHPh)(CO)9. The IR and 1H, 13C and 31P NMR data for the new complexes are reported and discussed. 相似文献
8.
D.P. Singh Vandna Malik Ramesh Kumar Jitender Singh 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):1201-1206
A new series of macrocyclic complexes of type [M(TML)X]X2, where M = Cr(III), Mn(III), or Fe(III), TML is tetradentate macrocyclic ligand, and X = Cl?, NO3?, CH3COO? for Cr(III), Fe(III) and X = CH3COO? for Mn (III), has been synthesized by condensation of benzil and succinyldihydrazide in the presence of metal salt. The complexes have been so formulated due to the 1:2 electrolytic nature of these complexes as shown by conductivity measurements. The complexes have been characterized with the help of various physicochemical techniques such as elemental analysis, molar conductance, electronic and infrared spectral studies, and magnetic susceptibility. On the basis of these studies, a five-coordinate distorted square pyramidal geometry, in which two nitrogens and two carbonyl oxygen atoms are suitably placed for coordination toward the metal ion, has been proposed for all the complexes. The complexes have been tested for their in vitro antibacterial activity. Some of the complexes show remarkable antibacterial activities against some selected bacterial strains. The minimum inhibitory concentrations shown by these complexes have been compared with those shown by some standard antibiotics such as linezolid and cefaclor. 相似文献
9.
Additional studies of solution phase recognition of Ru(NH3)x(pyridine)y2+, Ru(NH3)x(2,2′-bipyridine)y2+ and Ru(NH3)4(1,10-phenantroline)2+ species by dibenzo crown ethers are reported. The factors most closely examined were crown size, ammine ligand content and ancillary ligand composition. The overall study confirms that recognition or association derives primarily from H-bond formation (ammine hydrogen/ether oxygen. Evidently opposing these interactions, however, are crown conformational rearrangements. Consequently, straight-forward correlatins between association strength and potential number of H-bond interactions are found only in selected cases. Based on comparisons of association constants for (bis) pyridine, bipyridine and phenanthroline ligand-containing species with dibenzo crowns, evidence is also found for favorable polypyridine/benzene interactions. NMR (NOE) measurements indicate that the preferred association geometrics in solution are those that make each of the benzenes of the crown coplanar (or nearly coplanar) with the ligated polypyridine. 相似文献
10.
Taimur Athar 《Inorganica chimica acta》2005,358(15):4541-4547
New series of novel heterometallic fluorinated β-diketonato/alkoxo complexes have been synthesized in quantitative yields and characterized by analytical data, FT-IR, NMR and mass spectroscopy. Their thermal behavior was investigated by TGA. The plausible structure of β-diketonato/alkoxo complexes was suggested from the physico-chemical analysis. These complexes have been studied as potential precursors for planar optical amplifiers through the investigation of optical properties and a homogenous thin film spin coating. The volatility of these complexes was reduced by intramolecular hydrogen bonding. The assembling of fluorinated β-diketonato/alkoxo ligands ensures high coordination numbers for coordinated metals and improves their stability in ambient atmosphere. 相似文献
11.
A series of macrobicyclic mono and binuclear nickel(II) complexes of type [NiL](ClO4) and [Ni2L](ClO4)2, where L is macroyclic ligand derived from the precursor compound 3,4:10,11-dibenzo-1,13[N,N′-bis{(3-formyl-2-hydroxy-5-methyl)benzyl}diaza]-5,9-dioxocyclopentadecane, have been synthesized in order to examine electrochemical and catalytic studies on the basis of macrocyclic ring size. The macrocycle consists of three dissimilar compartments arising from ether oxygen, tertiary nitrogen and imine nitrogen atoms. Electrochemical studies have shown that the mononuclear nickel(II) complexes undergo quasireversible single step one electron reduction and oxidation and binuclear nickel(II) complexes undergo two quasireversible one electron reduction and oxidation. The EPR silent nature is ascribed to Ni(II) state and all the nickel(II) complexes have square planar geometry and are diamagnetic in nature. The complexes were subjected to hydrolysis of 4-nitrophenyl phosphate and the catalytic activities of the complexes are found to increase with macrocyclic ring size of the complexes. As the macrocyclic ring size of the complexes increases, the spectral, electrochemical and catalytic studies of the complexes show remarkable variation due to distortion in the geometry around the nickel(II) centre. 相似文献
12.
Hassan Keypour Hamid Goudarziafshar Robin G. Pritchard 《Inorganica chimica acta》2008,361(5):1415-1420
A series of Mn(II) macrocyclic Schiff-base complexes [MnLn]2+ have been prepared via the Mn(II) templated [1+1] cyclocondensation of 2,9-dicarboxaldehyde-1,10-phenanthroline with appropriate linear and branched amines. In this way ligands the pentaaza macrocycle L1 which is 15-membered and L2 which is 16-membered possessing no pendant arm, L6 is 15-membered with one 2-aminoethyl pendant arm and L8 which is 18-membered hexaaza macrocycle with two 2-aminoethyl pendant arms are formed. All the complexes have been characterized using spectroscopic methods. The crystal structures of [MnL8](ClO4)2 · EtOH were determined and indicate that in the solid state the complex adopts a slightly distorted hexagonal bipyramid geometry with the Mn(II) ion located within a hexaaza macrocycle with the two pendant amines coordinating in the axial positions. 相似文献
13.
Adrián Castillo 《Inorganica chimica acta》2010,363(6):1204-1211
Deprotonation of the p-tert-butylcalix[4]arene disubstituted at alternate phenolic positions with picolyl groups 2 was achieved with alkali metal hydrides LiH, NaH, and KH. The dianionic calixarene derivatives were subjected to complete substitution at the phenolic rim with allyl bromide, providing the tetraalkylated derivatives in cone 3a and partial-cone conformations 3b; both compounds were crystallographically characterized. Compound 2, as well as 3a and 3b were tested as ligands towards CuCl2, affording Cu2+ complexes in the first two cases. Polymeric [2·CuCl2] was obtained from 2 and CuCl2 in MeOH/CH2Cl2 solutions, and consists of chains of the ditopic calixarene acting as an N-donor towards Cu2+ ions outside the macrocyclic cavity. Employment of EtOH/CH2Cl2 mixtures results in the tricopper complex [(2)2Cu3Cl6(EtOH)2]. In contrast, reactions of ligand 3a with CuCl2 afforded monomeric [3a·CuCl2], while no Cu2+ complexes could be obtained when 3b was employed. The presence of intramolecular hydrogen bonds in 2 appears to control the formation of oligomeric or polymeric copper complexes, while the lack of such hydrogen bonds allows the proper alignment of N-donors to coordinate Cu2+ directly above the macrocyclic cavity. 相似文献
14.
The synthesis of bis-cyclometalated [Ir(ptpy)2(gly-gly-OEt)] (2, ptpy = 2-(p-tolyl)pyridinato; gly-gly-OEt = glycylglycine ethyl ester) and [Ir(ptpy)2(gly-gly-gly-OEt)] (3, gly-gly-gly-OEt = glycylglycylglycine ethyl ester) from the reaction of [{Ir(μ-Cl)(ptpy)2}2] (1) with the corresponding peptide ester hydrochlorides in the presence of NaOMe is described. The molecular structure of 2 was confirmed by a single-crystal X-ray diffraction study. The compound crystallized from dichloromethane/iso-hexane in the space group P21/a. In the crystal packing the molecules of 2 exhibit N–H?O hydrogen bonds to the neighbor molecules to form dimeric units. The absorption and emission spectra of 2 and 3 were recorded and exhibit these compounds as strong green-emitting complexes. 相似文献
15.
Alexander G. Martynov Olga V. Zubareva Sergey G. Sakharov 《Inorganica chimica acta》2009,362(1):11-7171
Four complexes - [(15C5)4Pc]M(Pc)M(Pc), (Pc2− - phthalocyaninato-dianion, [(15C5)4Pc]2− - 2,3,9,10,16,17,24,25-tetrakis(15-crown-5)phthalocyaninato-dianion, M = Sm, Dy, Tm, Y) were obtained via the reaction of M(Pc)2, H2[(15C5)4Pc] and M(acac)3. The influence of the stability of starting M(Pc)2 on the yields of target compounds was investigated. Increasing the stability of M(Pc)2 leads to higher yields of [(15C5)4Pc]M(Pc)M(Pc) and lower yields of scrambling products. All complexes were characterized by 1H NMR, UV-Vis and FT-IR spectroscopy as well as MALDI TOF mass-spectrometry. The analysis of 1H NMR spectra was performed in terms of lanthanide-induced shifts. Cation-induced dimerisation was studied by means of spectrophotometric titration. Supramolecular dimers {2[(15C5)4Pc]M(Pc)M(Pc) · 4K+} are the largest discrete cofacial supramolecular assemblies built of phthalocyanine building blocks reported up-to-date. The observed increase of the intermolecular excitonic interaction between building blocks with the increase of REE(III) size is tentatively explained in terms of metal-size dependent deformation of phthalocyanine ligands in sandwich complexes. 相似文献
16.
The crystal and molecular structures of the N-rac-isomer of the nickel(II) complex of 14-membered amide-containing macrocycle [NiL1] · 4H2O (H2L1=5,12-dioxo-1,4,8,11-tetraazacyclotetradecane) have been determined. Two deprotonated amide and two amine donors co-ordinate to the nickel(II) in nearly square planar manner with Ni-Namine bonds longer than Ni-Namide ones (1.930 vs. 1.898 Å). Water molecules do not co-ordinate and form hydrogen bond bridges between macrocyclic units in the crystal lattice. The analysis of 1H NMR data confirmed that the solid-state conformation of the macrocycle in N-rac[NiL1] is retained in aqueous solution though equilibrated with some amount of N-meso isomer. The comparison of the spectroscopic characteristics of the M(II) and M(III) complexes and the redox potentials of M(III/II) couples (M=Ni and Cu) for ML1 with those for ML2(H2L2=5,7-dioxo-1,4,8,11-tetraazacyclotetradecane) revealed a rather small influence of the trans- vs. cis-arrangement of amide donors in co-ordination spheres of the metal ions. 相似文献
17.
Tong-Bu Lu Guang-Chuan Ou Long Jiang Xiao-Long Feng Liang-Nian Ji 《Inorganica chimica acta》2005,358(11):3241-3245
Two nickel (II) complexes with the formula [NiL(H2O)2] · 6H2O (1 · 6H2O) and [NiH2L(BDC)]n (2), where L = 3,10-bis(3-propylcarboxyl)-1,3,5,8,10,12-hexaazacyclo-tetradecane, BDC = trans-butene dicarboxylate, have been synthesized and characterized by elemental analyses, IR spectra and single-crystal X-ray analyses. In 1, the Ni(II) ion is six-coordinated with four nitrogen atoms from the macrocyclic ligand in the equatorial plane and two water molecules in axial position. In 2, the structure is made up of one-dimensional chain of [NiH2L]2+ units with BDC2− anions, in which the Ni(II) ion is also six-coordinated with four nitrogen atoms from the macrocyclic ligand in the equatorial plane and two carboxylate oxygen atoms from the BDC2− group in axial position. In 2, the 1D chains are aligned in a parallel mode. 相似文献
18.
Disulfide monoribbed-functionalized clathrochelates (i.e., fuctionalization of one of the three α-dioximate fragments) with ribbed thioalkyl, S3-thioalkyl and hydroxythioalkyl substituents have been synthesized starting from the FeBd2(Cl2Gm)(BF)2 precursor (where Bd2− and Cl2Gm2− are α-benzyldioxime and dichloroglyoxime dianions) using the corresponding thiol/triethylamine system in dichloromethane solution. Clathrochelate S6-dithiol in basic media underwent the intramolecular dealkylation to yield the S3-thiocrown etheric clathrochelate. Clathrochelates obtained have been studied as the ligands toward Pt2+ and Pt4+ ions. The S-demethylation reaction of the methylsulfide complex with [PtCl4]2− dianion produced the polynuclear complexes of the dianionic clathrochelate dithiolate ligand. The reaction of n-butylsulfide clathrochelate with the trans-PtIVCl4(C6H5CH2CN)2 afforded the binuclear compound with the disulfide iron(II) clathrochelate as a monodentate ligand. The obtained macrobicycles, their clathrochelate derivatives, and polynuclear complexes have been characterized using elemental analysis, MALDI-TOF and PD mass, IR, UV-Vis, and NMR spectra, and X-ray crystallography. The encapsulated iron(II) ion coordination polyhedra distortion angle φ values and the main distances in the molecules of polynuclear complexes have been deduced (obtained) using 57Fe Mössbauer parameters and EXAFS data, respectively. 相似文献
19.
Copper(II) cations coordinated with PMDTA (pentamethyldiethylenetriamine) and TMEDA (tetramethylethylenediamine) possess a high synthetic potential. The synthesis of these cations was carried out by metathesis reactions with silver salts. The cationic copper(II) complexes, [Cu(PMDTA)(Me2CO)Cl]+, [Cu(PMDTA)(H2O)Cl]+, [Cu(PMDTA)(DMF)]+, [Cu(PMDTA)Cl]+, [Cu(PMDTA)OAc]+, [Cu(PMDTA)(MeCN)2]2+, [Cu2(TMEDA)2Cl3]+ and [Cu(TMEDA)(MeCN)3]2+ were synthesised as PF6 salts, crystallised and characterised by single-crystal X-ray diffraction. 相似文献
20.
Yan Z. Voloshin Oleg A. Varzatskii Andrey Yu. Lebedev Mikhail E. Gurskii Zoya A. Starikova 《Inorganica chimica acta》2007,360(5):1543-1554
The iron(II) clathrochelates with apical adamantyl substituents were synthesized by the direct template reaction on a metal ion matrix. The nucleophilic substitutions of reactive hexachloride precursors with adamantylthiolate anion afforded hexa- and octaadamantyl cage iron(II) complexes. Clathrochelates obtained have been characterized using elemental analysis, MALDI-TOF mass, IR, UV-Vis, 57Fe Mössbauer and 1H, 13C NMR spectroscopies, and X-ray crystallography. Configurations intermediate between trigonal prismatic and trigonal antiprismatic have been deduced for the low-spin iron(II) ion coordination polyhedra of all clathrochelates obtained using 57Fe Mössbauer parameters and confirmed by X-ray crystallography data. Two apical and up to six ribbed adamantyl substituents allow one to change the physical properties of clathrochelates synthesized in wide range. In particular, these substituents form second (hydrophobic) shell that opens up the possibility to membrane and cellular transport of the cage complexes. 相似文献