1-Pyrenecarboxaldehyde thiosemicarbazone:A novel fluorescent molecular sensor towards mercury(Ⅱ) ion

A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emission channels.The UV-vis spectra show that the increasing mercury（Ⅱ） ion concentrations result in the decreasing absorption intensity.The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury（Ⅱ） ion,which should be due to the 1：1 complex formation between Hpytsc and metal ion.

Microwave-assisted synthesis of new N^4-[bi-(4-fluorophenyl)-methyl]-piperazine thiosemicarbazones under solvent-free conditions

Six new N4-[bi-（4-fluorophenyl）-methyl]-piperazine thiosemicarbazones 3a-f have been prepared starting from [bi-（4-fluorophenyl）-methyl]-piperazine in solvent-free condition under microwave irradiation with excellent yields. Their structures have been determined by elemental analysis, IR, MS and 1H NMR data.

Metal 2-Hydroxy-1-Naphthaldehyde Thiosemicarbazone (Me-HNT) Complexes-A New Kind of Biomimic Enzyme Catalyst

Metal (Me=Fe(III), Mo(VI), Mn(II), Co(II), Ni(II), Zn(II) and Cu(II)) 2-hydroxy-1-naphthaldehyde thiosemicarbazone complexes (MeHNT) were synthesized and used as mimic-enzyme catalysts to mimic the active group of horseradish peroxidase (HRP). The results showed that Fe-HNT, Mo-HNT are effective catalysts, which have similar catalytic activity as HRP. The sequence of catalytic activities of tested biomimic peroxidas is Mo-HNT > Fe-HNT > Zn-HNT > Ni-HNT > Mn-HNT. Among them, Fe-HNT is used as a mimic-enzyme catalyst in determination of ascorbic acid and glucose by coupling the catalytic reaction of glucose oxidase.

Structure and Luminescence Property of a Hexanuclear Silver(I) Cluster Containing Pyridine-3-carboxaldehyde Thiosemicarbazone

A new hexanuclear silver（I） compound containing thiosemicarbazone with group of 3-pyridine was synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analysis and fluorescence spectrum.The title compound 3 crystallizes in monoclinic,space group C2/m with a = 18.6523（9）,b = 24.7519（11）,c = 22.4542（15） ,β = 93.4960（10）°,V = 10347.4（10）3,C68H104Ag6N30O8S6,Mr = 2309.39,Dc = 1.482g/cm3,μ（MoKα） = 1.293 mm-1,F（000） = 4656,Z = 4,the final R = 0.0544 and wR = 0.1580 for 6733 observed reflections（I 〉 2σ（I））.In the structure,two Ag6L36（L3 = pyridine-3-carboxaldehyde thiosemicarbazone） clusters are contained.In each cluster,the S atom of ligand L3 served as a triply bridged chelator to connect the six silver atoms into a Ag6L36 cluster.Luminescence investigation revealed that the band at 630 nm was attributed to cluster-centered（CC） electron transfer,and those at 493 and 530 nm to the LMCT and CC transitions,respectively.

Structure and Luminescence Property of a Hexanuclear Silver(Ⅰ) Cluster Containing Benzaldehyde Thiosemicarbazone

A new hexanuclear silver （I） compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in triclinic, space group P with a = 11.611（3）, b = 15.610（5）, c = 15.624（7） , α = 113.942（6）, β = 104.520（6）, γ = 104.230（4）°, V = 2304.1（14） 3, C60H77Ag6N22O4.5S6, Mr = 2018.02, Dc = 1.454 g/cm3, μ（MoKα） = 1.435 mm-1, F（000） = 1005, Z = 1, the final R = 0.0468 and wR = 0.1474 for 6608 observed reflections （I 2σ（I））. In the structure, the S atom of the ligand L2 （L2 = benzaldehyde thiosemicarbazone） served as a triply bridged chelator to connect the six silver atoms into a Ag6L26 cluster. The luminescence property of compound 2 was investigated at room temperature.

Structure and Luminescence Property of a Hexanuclear Thiosemicarbazone Silver(I) Cluster

A new hexanuclear silver（I） compound containing thiosemicarbazones with groups of 1-naphthalene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in monoclinic, space group P21/c with a = 16.101（4）, b = 24.855（7）, c = 14.492（4） A, β = 109.730（5）, V = 5459（3） A3, C90H102Ag6N2406S6, Mr= 2455.54, Dc= 1.494 g/cm3,μ（MoKa） = 1.228 mm^-1, F（000） = 2472, Z = 2, the final R = 0.0761 and wR = 0.1507 for 5258 observed reflections （I〉 2α（I））. In the structure, the S atom of ligand L serves as a triply bridged chelator to connect the six silver atoms into a Ag6L6 cluster. Luminescence investigation reveals that the compound exhibits two ligand-independent cluster-centered electron transfer bands and one ligand-dependent charge transfer band.

Preparation of p-Hydroxybenzaldehyde by Hydrolysis of Diazonium Salts Using Rotating Packed Bed

A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.

Antitumor Metallothiosemicarbazonate:Synthesis,Crystal Structure,Spectra and Antitumor Studies of Co(Ⅲ) Complex with Thiosemicarbazone Derivative of 2-Benzoylpyridine

The title complex [Co（L）2]Cl·4H2O I has been achieved via self-assembly by incorporating cobalt into 2-benzoylpyridine thiosemicarbazonate ligand, and characterized by elemental analysis, infrared spectra, mass spectra and single-crystal X-ray diffraction study. The crystal crystallizes in monoclinic, space group P2 1/n, with a = 10.227（3）, b = 17.363（4）, c = 17.459（4） A, β= 100.408（4）°, V= 3049.2（13） A^3, Z = 4, Mr = 677.08, Dc = 1.475 g/cm^3, μ（MoKα） = 0.834 mm^-1, F（000） = 1400, the final R = 0.0747 and wR = 0.0896 for 1663 observed reflections with I 〉 2σ（I）. The complex contains one six-coordinated cobalt ion connected by two thiosemicarbazone ligands which act as a tridentate ligand to coordinate with the center metal atoms via two pyridyl nitrogen atoms, two imine nitrogen atoms and two sulfur atoms giving rise to a mononuclear structure. Hydrogen bonds existing in the complex link the different components to stabilize the crystal structure. The antiturnor activity of the title complex was tested against A549 lung cancer cell line. Complex ! exhibits antitumor activity.

Synthesis and Cytotoxicity of the First Arene Ruthenium Compound Containing Two Thiosemicarbazone Ligands

A Ru-arene compound containing two thiosemicarbazone ligands [(η6-p-cymene)Ru(TSC)2 Cl]Cl(1, TSC = benzophenone 4-methylthiosemicarbazone) has been synthesized and characterized by 1 H NMR, elemental analysis and HR-ESI mass spectrometry analysis. The molecular structure was determined by single-crystal X-ray diffraction analysis. The in vitro anticancer activities of the complex have been evaluated against two human cancer cell lines(SGC-7901, BEL-7404), and the IC50 values are 32.5 and 57 μM, respectively.

Cu(II) Propionyl-Thiazole Thiosemicarbazone Complexes: Crystal Structure, Inhibition of Human Topoisomerase IIα, and Activity against Breast Cancer Cells

Two new thiosemicarbazone ligands, 2-propionylthiazole ethylthiosemicarbazone (PTZ-ETSC), and 2-propionylthiazole tert-butylthiosemicarbazone (PTZ-tBTSC), along with their two copper(II) complexes, [Cu(PTZ-ETSC)Cl] and [Cu(PTZ-tBTSC)Cl], are reported here for the first time. Once characterized by NMR and MS, these mono-anionic tridentate ligands were reacted with Cu2+ to form the square planar metal complexes [Cu(PTZ-ETSC)Cl] and [Cu(PTZ-tBTSC)Cl]. The x-ray crystal structure of the [Cu(PTZ-tBTSC)Cl] complex shows that the complex adopts a square planar arrangement around the copper(II) ion, but forms a sulfur-bridged dimer in the solid state. Both of the copper complexes displayed strong inhibition of human topoisomerase IIα at activities between 2-4 μM for [Cu(PTZ-ETSC)Cl], and between 8-10 μM for the [Cu(PTZ-tBTSC)Cl] complex. The EC50 values for the MDA-MB-231 breast cancer cell line were 82.6 μM for (PTZ-ETSC), 17.9 μM for [Cu(PTZ- ETSC)Cl], 97.8 μM for (PTZ-tBTSC), and 1.41 μM for [Cu(PTZ-tBTSC)Cl]. The EC50 values for the MCF7 breast cancer cell lines were 9.36 μM for (PTZ-ETSC), 0.13 μM for [Cu(PTZ-ETSC)Cl], 0.333 μM for (PTZ-tBTSC), and 0.093 μM for [Cu(PTZ-tBTSC)Cl].

Synthesis and Characterization of Novel Thiosemicarbazones Bearing Sugar Moieties

Six novel thiosemicarbazones containing sugar and thiosemicarbazide moieties were synthesized by a five-step procedure using D-galactose and D-xylose as the starting materials and the corresponding glycosyl isothiocyanates as the intermediates. The target compounds were characterized by IR, ^1H NMR, and elemental analysis. The coupliug constants between H1 and H2 in the sugar rings, all fail within the range of J = 9. 2-10.0 Hz, confirming the β-configuration of the compounds.

Cu(II) Benzoylpyridine Thiosemicarbazone Complexes: Inhibition of Human Topoisomerase IIα and Activity against Breast Cancer Cells

The focus of this research is on the study of a series of copper (II) benzoylpyridine thiosemicarbazone complexes. Of the six benzoylpyridine thiosemicarbazone ligands used in this study, two are reported for the first time;2-benzoylpyridine tert-butyl thiosemicarbazone (BZP-tBTSC), and 2-benzoylpyridine benzyl thiosemicarbazone (BZP-BzTSC). Once characterized by NMR, melting point, and MS, these mono-anionic tridentate ligands were then reacted with Cu2+ to form the new square planar metal complexes [Cu(BZP-tBTSC)Cl] and [Cu(BZP-BzTSC)Cl]. All of the copper complexes display marked inhibition of human topoisomerase IIα. The [Cu(BZP-tBTSC)Cl] complex shows marked activity against human breast cancer cell lines.

Investigation of the Lipophilicity of 2-Benzoylpyridine-Thiosemicarbazone Based on the Ion Transfer across the Liquid/Liquid Interface

The ion transfer reaction of 2-benzoylpyridine-thiosemicarbazone (HL), which has antimicrobial and antifungal properties and anticancer activity, has been studied to determine its lipophilicity by cyclic voltammetry at the water/1,2-dichloroethane (1,2-DCE) interface. The physicochemical parameters such as standard partition coefficient (lgPI)andthestandardGibbsenergyoftransfer("G0tr,,wI "o)oftheprotonatedformoftheligandwere measured asa function of pH in aqueous phase. The protonated form of the ligand exhibited reversible or quasi-reversible voltammograms at the1,2-DCEintherangeofpH1-5.Theprotonationconstantsoftheligand,pKa1andpKa2,weredeterminedspectrophotometrically and were found to be 12.14 and 3.24, respectively. The standard Gibbs energy of transfer ("G0tr,,wN" o) and the partition coefficient of neutral species (lgPN) were also determined by the shake-flask method. The standard Gibbs energy of transfer of this compound across the water/1,2-DCE interface was evaluated as the quantitative measure of its lipophilicity. The difference between lgPI and lgPN was related to the degree of charge delocalization and was used to evaluate qualitatively the lipophilicity of the ligand.

Synthesis and Structure of 2-Acetylthiophene Thiosemicarbazone

Acetylthiophene thiosemicarbazone(C4H4S) C (CH3)=NNHC-SNH2-·1/2H2O has been prepared by the condensation of 2-acetylthiophene with thiosemicarbazide. This compound crystallized in monoclinic space group P21/c with unit cell parameters: a = 15. 909 (2) , b = 5 .424 (3)A,β=108. 59 (1)°,V=1989 (1)A 3, Z=8, Dc= 1.391g/cm3, F(000)= 872, λ=0.71073 A,μ(MoKα) = 4. 7 cm-1, final RO= 0.36 for 2852 observed reflections. Analysis of molecular structure reveals that this Schiff base possesses the E-form configuration. Each asymmetric unit contains two thiosemicarbazones and one water molecule which form hydrogen bonds statistically.

GC/MS Analyses of Thiosemicarbazones Synthesized from Acetophenones: Thermal Decay and Mass Spectra Features

The mass spectral fragmentation of thiosemicarbazones synthesized from acetophenones has been studied by CG/MS. These carbonyl compounds exhibit chromatographic peaks which are not observed in aliphatic analogues or those synthesized from aldehydes. The analysis of the corresponding spectra has allowed structural assignment to the dimerization of gas phase neutral fragments. Theoretical calculations (DFT level) also provide evidence to support the experimental observations.

Preparation,Characterization and Crystal Structure Determination of a Nickel Complex [Ni(ftsc)_2NO_3]NO_3(Hftsc=Furan-2-carbaldehyde Thiosemicarbazone)

A new Ni（II） complex, [Ni（ftsc）2NO3]NO3 （Hftsc = furan-2-carbaldehyde thiosemicarbazone）, has been synthesized and characterized by IR, UV spectra and single-crystal X-ray diffraction analysis. It crystalfizes in a monoclinic system, space group P2 1/n, with a = 10.5203（13）, b = 9.2094（11）, c = 20.829（3）A,β = 91.518（2）°, V= 2 017.3（5）A^3, Z = 4, F（000） = 1064, Dc = 1.716 g/cm^3, and wR = 0.0800. The complex contains a six-coordinated nickel（II） center which is bound to two imine nitrogen atoms and two thiolato sulfur atoms of two ligands as well as two oxygen atoms from a nitrate anion to assume a distorted octahedral coordination geometry. In addition, intermolecular N-H…O and C-H…O hydrogen bonds between adjacent molecules link the molecules together to form a three-dimensional structure.

Antitumor Comparison of Three α-N-Heterocyclic Thiosemicarbazone Derivatives' Crystal Structures of Bis(2-acetylpyridine)thiocarbonohydrazone and Bis(imidazole-2-carboxaldehyde)thiocarbonohydrazone

A series of ligands,HL1（2-acetylpyridine thiosemicarbazone）,H2L2（bis（2-acetyl-pyridine） thiocarbonohydrazone） and H2L3（bis（imidazole-2-carboxaldehyde） thiocarbonohydrazone） was synthesized.H2L2 and H2L3 were characterized by elemental analysis,IR spectra and single-crystal X-ray diffraction studies.Hydrogen bonds link different components to stabilize the crystal structure in the two ligands.To comprehend the structure-activity relationship well,the three ligands are all tested against human K562 leucocythemia cell line with IC50 analysis.Different substituent groups on the ligands show different levels of antitumor activity.By comparison with the other species studied,H2L2 with thiocarbonohydrazone along with 2-acetylpyridine is the most active compound with IC50 = 2.48 μM.

Thiosemicarbazones Synthesized from Acetophenones: Tautomerism, Spectrometric Data, Reactivity and Theoretical Calculations

Tautomeric forms of Thiosemicarbazones have been investigated by spectrometric methods, their chemical reactivity and theoretical calculations of the relative tautomers stabilities. The mass spectral fragmentation of thiosemicarbazones synthesized from acetophenones has been studied by CG/MS. The analysis of the corresponding spectra shows not only the regular fragmentation mechanisms but homolytic ruptures from even-electron species. 1H NMR spectra exhibit signals for the most intense open thioketo tautomeric structure, although when using TFA a ring structure is observed in the corresponding tautomeric equilibrium. Density Functional Theory calculations (DFT) also provide evidence to support the experimental observations by GC-MS and 1H NMR. Methylation reactions give support to the occurrence of the thioenol tautomeric form which would be the second most abundant according to the Density Functional Theoretical calculations.

Synthesis, Structure and Comparison of Luminescent Property between Two Hexanuclear Silver(Ⅰ) Thiosemicarbazone Clusters

A new silver（Ⅰ） compound 4 containing thiosemicarbazone with group 2-quinoline was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. Compound 4 crystallizes in triclinic, space group P1 with a = 12.2710（9）, b = 16.9281（13）, c = 17.2984（13）, α = 112.8500（10）, β = 103.4890（10）, γ = 102.6860（10）°, V = 3020.9（4） 3, C80H94Ag6N28O6S6, Mr = 2383.41, Dc = 1.310 g/cm3, μ（MoKα） = 1.108 mm-1, F（000） = 1196, Z = 1, the final R = 0.0567 and wR = 0.1368 for 5112 observed reflections （I 〉 2σ（I））. Similar to the structure of compound 2 we have reported, compound 4 also exhibits a hexanuclear silver（Ⅰ） cluster. In the cluster, the S atom of ligand L4 （L4 = 2-quinolinecarboxaldehyde thiosemicarbazone） serves as a triply bridged chelator to connect the six silver atoms into a Ag6L46 cluster. The luminescence property of 4 is investigated at room temperature and compared with that of 2.