查看更多>>摘要：A new 4-amino-1,8-naphthalimide hydrazine fluorophore (Nap-NH2) has been synthesized in quantitative yield via a one-pot imidation reaction between 4-amino-1,8-naphthalic anhydride and hydrazine hydrate (N2H4 center dot & nbsp;H2O) and successfully employed as a fluorescent "turn-on " chemosensor for metal cations. The sensor Nap-NH2 displayed a positive solvatochromism in different solvents with varying polarities. The fluorescence titration studies of Nap-NH2 with various metal cations disclosed the high selectivity and reversible binding affinity of Nap-NH2 towards Zn(II) ions with nanomolar (10 nm) sensitivity. The fluorescence emission intensity of Nap-NH2 was drastically enhanced upon binding with Zn(II) ion and the Stern-Volmer binding constant is K-SV = 1.13 x 10(4) M-1. Interestingly, the presence of commonly coexisting different metal cations {Fe(II), Cu(II), Mg(II), Cd(II), Ni (II), Co(II), Mn(II), Ba(II), Al(III), Ce(III), Sn(II), Pb(II), Cr(III) and Ca(II)} showed negligible changes in the emission intensity and thus weak binding interactions with Nap-NH2. These studies demonstrate that Nap-NH2 is a potential fluorescence "turn-on " chemosensor for selective, sensitive detection and quantification of biologically relevant metal cations.
查看更多>>摘要：A novel salamo-based fluorescent sensor H3L was synthesized and characterized by IR, H-1 NMR and ESI-MS. The results showed that the fluorescence spectra and UV-Vis absorption spectra of H3L changed with the addition of Cu2+ and Arg respectively. The introduction of Cu2+ ions caused significant fluorescence quenching. The combination of Cu2+ ions and the sensor was confirmed by X-ray crystallography of the copper(II) complex [{Cu-2(L)}(2)](ClO4)(2)center dot H2O, which can lead to fluorescence quenching through coordination coupling. The response of the amino acid Arg to H3L was turned on by fluorescence and their combination was characterized by IR and ESI-MS. The sensitivity of the fluorescence response to Cu2+ ion and Arg was determined by their LODs 6.5084 x 10(-8) M and 1.7271 x 10(-7) M, respectively. At the same time, it was determined by titration experiments that H3L and Cu2+ ions are combined at a ratio of 1:2, and 1:1 with Arg. Calculating their binding constants are 6.91 x 10(9) M-1 and 3.17 x 10(9) M-1, respectively.
查看更多>>摘要：Two new crystalline dithiocarbamato-chlorido complexes of mercury(II), [Hg-2{S2CN(C4H9)(2)}(2)Cl-2] (1) and [Hg-4{S2CN(iso-C4H9)(2)}(6)][Hg2Cl6] (2), have been prepared and chemically identified by solution (H-1, C-13) NMR and solid-state (C-13, N-15) CP-MAS NMR and FT-IR spectroscopy. The crystal, molecular and supramolecular structures of these compounds were established using single-crystal X-ray diffraction (XRD) analysis. The obtained complexes reveal two principally different types of structural organisation. In the structure of the former neutral complex, there are two isomeric doubly-bridged binuclear molecules [Hg-2(S2CNBu2)(2)Cl-2] ('A' and 'B'), whereas the latter compound comprises two ionic structural moieties: the tetranuclear cation [Hg-4(S2CNiBu2)(6)](2+) and the binuclear anion [Hg2Cl6](2-). In both ionic units, pairs of iBu(2)Dtc or chloride ligands, which perform a bridging structural function, combine with neighbouring mercury atoms. In turn, intermolecular/interionic secondary interactions Hg center dot center dot center dot S/Hg center dot center dot center dot Cl are involved in the formation of supramolecular structures of complexes 1/2, yielding pseudo-polymeric chains of (center dot center dot center dot'A'center dot center dot center dot'B'center dot center dot center dot)(n)/(center dot center dot center dot[Hg-4(S2CNiBu2)(6)]center dot center dot center dot[Hg2Cl6]center dot center dot center dot)(n), which exhibit alternation of isomeric molecules of 1/ionic moieties of 2 along their lengths. Despite the significant structural difference between the above complexes, we established, using simultaneous thermal analysis (STA), that both exhibit very similar thermal behaviour. Moreover, during the thermal transformations of both compounds 1 and 2, the same two substances are generated: HgCl2 and HgS.
查看更多>>摘要：Tris(pentafluorophenyl)silanol (C6F5)(3)SiOH was prepared from the corresponding chlorosilane (C6F5)(3)SiCl by an unconventional controlled hydrolysis. The X-ray structure and the reactivity of the new silanol with various bases, with triflic acid and with some rhenium carbonyl complexes are reported. The Si-C6F5 bond is easily cleaved in the presence of even weak bases and this behaviour prevented the isolation of the (C6F5)(3)SiO- anion and the synthesis of the [Re(CO)(5)COSiR3] derivative. In particular, when (C6F5)(3)SiOH was reacted with butyl lithium and Re(CO)(5)OSO2CF3 the formation of [Re(CO)(5)C6F5] was observed.
查看更多>>摘要：In recent years, a lot of effort has gone into developing metal organic frameworks (MOFs) based composites as anticancer drug delivery carriers. Among them, various nanoparticles (NPs) such as graphene oxide (GO), Iron oxide (Fe3O4 or Fe2O3), zinc oxide has been utilized to impart additional benefits in MOFS structure. In this study, CeO2 particles and its composites with MIL-100(Fe) were studied for loading and subsequent release of the anticancer medication doxorubicin hydrochloride (DOX). The pure MIL-100(Fe) and CeO2@ MIL-100(Fe) composites were synthesised using two different methods: a traditional HF route (HF acts as a crystallising agent) and another without HF. It was found that during the composite synthesis, CeO2 was transformed to CeF3 in the presence of HF. The MOF-composites that resulted had a lower DOX loading capacity than pure CeO2 but were quite equivalent to pure MOF. However, in absence of HF, such transformation of CeO2 was not occurred in the composites. All the composites have a regulated DOX release pattern as compare to the undesirable burst release characteristics of pure CeO2.
查看更多>>摘要：Complexes of nickel(II), palladium(II) and zinc(II) have been synthesized with four ONS thiosemicarbazone tridentate ligands. The ligands were obtained from the synthesis of 2-hydroxy-3-methoxybenzaldehyde or 2,3-dihydroxybenzaldehyde with thiosemicarbazide or 4-ethyl-3-thiosemicarbazide. The palladium and zinc complexes have formula [ML](2) (H2L, ligand), whereas in the case of nickel, two different types of complexes are formed: [NiL](2) or [Ni(HL)(2)] depending on the starting metal ion:ligand ratio (1:1 or 1:2, respectively). The nickel (II) complex [Ni(H2L)(HL)](CH3COO) was characterized also by single crystal X-ray diffraction.& nbsp;While the ligands did not exhibit antiproliferative activity on human histiocytic lymphoma U937 cells, the metal complexes showed GI(50) values ranging from approximately 20 to 39 mu M. The most promising metal complexes were also tested through Alkaline Comet Assay: while with the ligand DNA damages were not detected even at the highest ligand concentrations (100 mu M), the complexes, and in particular the nickel dimers [NiL](2), exhibit genotoxic activity.
查看更多>>摘要：Catalysis, a rapidly growing field of science and technology, has brought about a paradigm shift in the direction to achieve desirable synthetic transformations utilizing numerous organometallic compounds. These organometallic complexes impart great activity not only by metal and ligand framework, however, the subtle alterations take a dramatic change in their activity, which knocks the door of their applications in the arena of drug discovery. In this review, we discussed about the recent trends (2015 onwards) in catalytic anticancer drugs and their mechanism of action against different potential targets (Fig. 1). We have comprehensively discussed about the transfer hydrogenation catalysis including, NADH/NAD(+) (Nicotinamide adenine dinucleotide) imbalance and pyruvate reduction. We briefly explained the important role of different catalysts (such as photocatalysts, and bioorthogonal catalysts) in the context of cancer therapeutics. Finally, we shed light on the advantages, limitations, and future scope for designing effective catalytic anticancer agents.
查看更多>>摘要：The reaction of indium(III) salts with Ph2PSiMe3 and PhP(SiMe3)(2) gives rise to a one-and two-electron reductive P-P coupling respectively, with the formation of new P-P bonds resulting in the preparation of (Ph2P)(2) and the cyclicoligophosphane compounds (PhP)(4) and (PhP)(6).
Han, XinghaoLiu, BinWang, ZhihongCraze, Alexander Ross...
9页
查看更多>>摘要：Based on asymmetric lithium salts of 1-(2-pyridinylmethyl)-pyrazole-3,5-dicarboxylate (2-Li(2)pmpd) or 1-(4-pyridinylmethyl)-pyrazole-3,5-dicarboxylate (4-Li(2)pmpd), four polymers [Mn(2-pmpd)(H2O)]n (1), {[Mn-2(4-pmpd)(pd)(H2O)(3)]center dot & nbsp;H2O}(n) (2), [Co(4-pmpd)(H2O)](n) (3) and [Co(2-pmpd)(H2O)2]n (4) [pd = pyrazole-3,5-dicarboxylate] have been hydrothermally prepared and characterized structurally. 1 displays three-dimensional (3D) network with (44.84) topology, 2 and 3 show 2D framework with (42.5.63)(42.52.64.72)(52.8) and (43)2(46.66.83) topologies, respectively. 4 is a 1D chain structure. Magnetization data of 1 with the 1D carbox-ylate bridges chain structure, fitted by the 1D model, suggests the antiferromagnetic coupling with J =-2.07 cm(-1). The carboxylate bridges in 1 adopt common syn -syn and unidentate oxygen-bridge modes. 2 with the Mn-4 unit, exhibits antiferromagnetic coupling with J =-0.68 cm-1 and zJ' =-0.317 cm(-1). The carboxylate bridges in 2 adopt common syn-anti and the unidentate oxygen-bridge modes. In the Co-2 units, magnetization data for 3 shows the weak antiferromagnetic coupling. Variable temperature magnetic studies of 4 reveal ferromagnetic intrachain interactions and antiferromagnetic interchain magnetization interactions. The M(H) curves for 3 and 4 are consistent with their antiferromagnetic or ferromagnetic natures.
查看更多>>摘要：2-benzoylpyridine semicarbazide/4-phenylsemicarbazide derived ligands as hydrochloride salts, [H2L]Cl and [H2LPh]Cl center dot 2H(2)O, react with Pb2+ ions in aqueous and organic milieus. The compounds [Pb-2(HL)(2)Cl-4]center dot 2DMF (1a), [Pb-2(HL)(2)Cl-4]center dot 5H(2)O (1b), [Pb-2(HL)(2)Cl-2(NO3)(2)]center dot 4H(2)O (2), [Pb-2(HL)(2()SCN)(4)] (3), [Pb-4(HLPh)(4)Cl-8] (4), [Pb(HLPh)(2)(NO3)(2)] (5) and [Pb(HLPh)(2)(SCN)(2)] (6) were obtained and characterized by powder X-ray diffraction and by infrared and ultraviolet-visible spectroscopies. Compounds 1-5 were analyzed by single-crystal X-ray diffraction. Tetrel and hydrogen bonds dominate the solid-state arrangements. The aqueous synthetic approach makes the pre-ligands of this work promising for further studies in aqueous coordination chemistry with p-block metal ions. [H2L]Cl and [H2LPh]Cl center dot 2H(2)O are suitable for coordination as neutral HL or HLPh species.
NSTL
Elsevier