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1.
Fillipe V. Rocha Carolina V. Barra Silmar J. S. Franchi Adelino V. G. Netto Antonio E. Mauro Regina C. G. Frem 《Journal of Thermal Analysis and Calorimetry》2011,106(2):385-389
Four new mononuclear Pd(II) complexes of the type [PdX2(tdmPz)] {X = Cl− (1); Br− (2); I− (3); SCN− (4); tdmPz = 1-thiocarbamoyl-3,5-dimethylpyrazole} have been synthesized and characterized by elemental analysis, IR spectroscopy,
1H and 13C{1H}-NMR experiments. The thermal behavior of the complexes 1–4 has been investigated by means of thermogravimetry (TG) and differential thermal analysis (DTA). From the initial decomposition
temperatures, the thermal stability of the complexes can be ordered in the sequence: 3 < 4 ≡ 2 < 1. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction. 相似文献
2.
Sahra C. Lemos Silmar J. S. Franchi Adelino V. G. Netto Antonio E. Mauro Oswaldo Treu-Filho Regina C. G. Frem Eduardo Tonon de Almeida Cláudia Torres 《Journal of Thermal Analysis and Calorimetry》2011,106(2):391-397
This work describes the synthesis, characterization, and the thermal behavior investigation of four palladium(II) complexes
with general formulae [PdX2(mba)2], in which mba = N-methylbenzylamine and X = OAc− (1), Cl− (2), Br− (3) or I− (4). The complexes were characterized by elemental analysis, infrared vibrational spectroscopy, and 1H nuclear magnetic resonance. The stoichiometry of the complexes was established by means of elemental analysis and thermogravimetry
(TG). TG/DTA curves showed that the thermodecomposition of the four complexes occurred in 3–4 steps, leading to metallic palladium
as final residue. The palladium content found in all curves was in agreement with the mass percentages calculated for the
complexes. The following thermal stability sequence was found: 3 > 2 > 4 > 1. The geometry optimization of 1, 2, 3, and 4, calculated using the DFT/B3LYP method, yielded a slightly distorted square planar environment around the Pd(II) ion made
by two anionic groups and two nitrogen atoms from the mba ligand (N1 and N2), in a trans-relationship. 相似文献
3.
Rodrigo A. de Souza Antonio E. Mauro Adelino V. G. Netto Gislaine A. da Cunha Eduardo T. de Almeida 《Journal of Thermal Analysis and Calorimetry》2011,106(2):375-378
Palladium(II) coordination compounds of general formula trans-[PdX2(isn)2], X = Cl− (1), N3
− (2), SCN− (3), NCO− (4), isn = isonicotinamide; were synthesized and characterized in solid state by elemental analysis, infrared spectroscopy,
and simultaneous TG–DTA. TG experiments reveal that the compounds 1–4 undergo thermal decomposition in three or four stages, yielding Pd0 as final residue, according to calculus and identification by X-ray powder diffraction. 相似文献
4.
Thermal behaviour of nickel amine complexes containing SO4
2−, NO3
−, Cl− and Br− as counter ions and ammonia and ethylenediamine as ligands have been investigated using simultaneous TG/DTA coupled with
mass spectroscopy (TG/DTA–MS). Evolved gas analyses detected various transient intermediates during thermal decomposition.
The nickel ammonium sulphate complex produces NH, N, S, O and N2 species. The nickel ammonium nitrate complex generated fragments like N, N2, NO, O2, N2O, NH2 and NH. The halide complexes produce NH2, NH, N2 and H2 species during decomposition. The ligand ethylenediamine is fragmented as N2/C2H4, NH3 and H2. The residue hexaamminenickel(II) sulphate produces NiO with crystallite size 50 nm. Hexaammine and tris(ethylenediamine)nickel(II)
nitrate produce NiO in the range 25.5 nm and 23 nm, respectively. The halide complexes produce nano sized metallic nickel
(20 nm) as the residue. Among the complexes studied, the nitrate containing complexes undergo simultaneous oxidation and reduction. 相似文献
5.
Francisco C. C. Arantes Antonio C. Moro Iolanda S. Klein Cristiana da Silva Adelino V. G. Netto Antonio E. Mauro Vânia M. Nogueira 《Journal of Thermal Analysis and Calorimetry》2011,106(2):379-383
The synthesis, spectroscopic characterization, and thermal analysis of the compounds [Pd(X)2(mtu)(PPh3)] (X = Cl− (1), SCN− (2); mtu = N-methylthiourea; PPh3 = triphenylphosphine) and [Pd(X)2(phtu)(PPh3)] (X = Cl− (3), SCN− (4); phtu = N-phenylthiourea) are described. The thermal decomposition of the compounds occurs in two, three, or four stages and the final
decomposition products were identified as Pd0 by X-ray powder diffraction. The thermal stability order of the complexes is 4 > 3>2 > 1. 相似文献
6.
Carolina V. Barra Fillipe V. Rocha Adelino V. G. Netto Regina C. G. Frem Antonio E. Mauro Iracilda Z. Carlos Sandra R. Ananias Marcela B. Quilles 《Journal of Thermal Analysis and Calorimetry》2011,106(2):489-494
This study describes the synthesis, IR, 1H, and 13C{1H} NMR spectroscopic as well the thermal characterization of the new palladium(II) pyrazolyl complexes [PdCl2(HmPz)2] 1, [PdBr2(HmPz)2] 2, [PdI2(HmPz)2] 3, [Pd(SCN)2(HmPz)2] 4 {HmPz = 4-methylpyrazole}. The residues of the thermal decomposition were identified as Pd0 by X-ray powder diffraction. From the initial decomposition temperatures, the thermal stability of the complexes can be ordered
in the sequence: 1 > 2 > 4 ≈ 3. The cytotoxic activities of the complexes and the ligand were investigated against two murine cancer cell lines: mammary
adenocarcinoma (LM3) and lung adenocarcinoma (LP07) and compared to cisplatin under the same experimental conditions. 相似文献
7.
Tahra Ayed Nathalie Guihéry Bahoueddine Tangour Jean-Claude Barthelat 《Theoretical chemistry accounts》2006,116(4-5):497-504
Correlated ab initio calculations have been performed on three dipalladium(I) complexes. These compounds differ both by the metal–metal interaction and by the metal–ligand interaction. The [Pd2Cl2(μ −H2PCH2PH2)2] complex exhibits a σ overlap between the two binding metallic orbitals and has no bridging ligand. In [Pd2Cl4(μ −CO)2]2−, the leading interaction between the two palladium involves a π overlap between the metallic orbitals and goes through the two bridging CO ligands. In [Pd2Cl2(μ −CO)(μ −H2PCH2 PH2)2], a single CO ligand bridges the two palladium atoms which interact through a hybrid σ–δ overlap. The three compounds also differ by the metal–metal distances. Surprisingly enough, while the palladium atoms are formally d
9 in all these complexes, none of them is paramagnetic. We propose here a detailed analysis of the electronic structures of these compounds and rationalize their chemical structures as well as the role of back-donation in the CO bridged compounds. Finally, since highly correlated treatments are used to describe these complexes, a detailed study of the role of both non-dynamical and dynamical correlations is performed. Concerning the [Pd2Cl4(μ −CO)2]2− complex, this analysis has revealed that the complex is not bound at the lowest correlated levels of calculation and therefore dynamical correlation is alone responsible for its binding energy. 相似文献
8.
A. V. G. Netto Regina C. G. Frem A. E. Mauro Marisa S. Crespi H. E. Zorel Jr 《Journal of Thermal Analysis and Calorimetry》2007,87(3):789-792
Synthesis, spectroscopic characterization
and thermal behavior of pyrazolate-bridged palladium complexes [Pd(μ-Pz)2]n
(1), [Pd(μ-mPz)2]n
(2), [Pd(μ-dmPz)2]n
(3), [Pd(μ-IPz)2]n
(4) {pyrazolate (Pz–),
4-methylpyrazolate (mPz–), 3,5-dimethylpyrazolate
(dmPz–), 4-iodopyrazolate (IPz–)}
have been described in this work. The exobidentate coordination mode of pyrazolato
ligands in 1–4
was inferred on basis of IR spectroscopic evidences. TG investigations indicated
that the introduction of substituents at the 4 position in the pyrazolyl moiety
into coordination polymers do not affect significantly their thermal stability,
whereas at the 3 and 5 position reduced the stability of the main chain. Metal
palladium was the final product of the thermal decompositions, which was identified
by X-ray powder diffraction. 相似文献
9.
The reaction of [M(L)]Cl2 · 2H2O (M = Ni2+ and Cu2+, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with 1,1-cyclobutanedicarboxylic acid (H2-cbdc) generates 1D and 2D hydrogen-bonded infinite chains [Ni(L)(H-cbdc−)2] (1) and [Cu(L)(H-cbdc−)2] (2). (H-cbdc− = cyclobutane-1-carboxylic acid-1-carboxylate). These complexes have been characterized by X-ray crystallography, spectroscopy,
and cyclic voltammetry. The crystal structure of 1 shows a distorted octahedral coordination geometry around the nickel(II) ion, with four secondary amines and two oxygen atoms
of the H-cbdc− ligand at the trans position. In 2, the coordination environment around the central copper(II) ion shows a Jahn–Teller distorted octahedron with four Cu–N bonds
and two long Cu–O distances. The cyclic voltammogram of the complexes undergoes two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature
of the axial H-cbdc− ligand. 相似文献
10.
Shu-Jian Chen Julia K. C. Abbott Carlos A. Steren Zi-Ling Xue 《Journal of Cluster Science》2010,21(3):325-337
Metal cage complexes [(Me2N)3MO]4 (M = Nb, 3; Ta, 4) have been prepared from the reactions of M(NMe2)5 (M = Nb, 1; Ta, 2) with water. Single crystal X-ray diffraction studies of 3 and 4 reveal that they adopt cubane-like structures with M–O bridges. Variable-temperature NMR studies of –NMeAMeB rotations in 3 and 4 have been performed to give the following activation parameters for the exchanges: ΔH
≠ = −1.4(1.1) kJ/mol, ΔS
≠ = −209(8) J/mol K,
\Updelta G 30 8 \textK 1 = 6 4( 2) \textkJ/\textmol \Updelta G_{{_{{ 30 8\;{\text{K}}}} }}^{{^{ \ne } }} = 6 4\left( 2\right)\;{\text{kJ}}/{\text{mol}} for 3, and ΔH
≠ = −0.9(1.2) kJ/mol, ΔS
≠ = −2.1(0.2) × 102 J/mol K,
\Updelta G 30 8 \textK 1 = 6 3( 6) \textkJ/\textmol \Updelta G_{{ 30 8\;{\text{K}}}}^{{^{ \ne } }} = 6 3\left( 6\right)\;{\text{kJ}}/{\text{mol}} for 4. 相似文献
11.
Wei Li Yun-Li Liu Jian Liu Huai-teng Zhang Shu-Zhong Zhan De-Rong Cao 《Transition Metal Chemistry》2011,36(3):255-260
The triazenide, 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene (HL), has been synthesized. In the presence of Et3N, the reaction of HL with Cu(OAc)2·H2O or CuCl2·2H2O gives the tetranuclear copper(II) complexes {Cu4(L)2(μ2-OH)2(OAc)4} 1 and {Cu4L4(μ4-O)Cl2} 2, respectively. The X-ray crystal structures of both complexes have been obtained. Magnetic studies indicate significant antiferromagnetic
coupling between the copper(II) centers for both complexes, with coupling constants (J) of −493.4 cm−1 for 1 and −165 cm−1 for 2. 相似文献
12.
R. L. Fernandes P. M. Takahashi R. C. G. Frem A. V. G. Netto A. E. Mauro J. R. Matos 《Journal of Thermal Analysis and Calorimetry》2009,97(1):123-126
The synthesis and thermal behavior of the new [Pd(fum)(bipy)]
n
·2nH2O (1), [Pd(fum)(bpe)]
n
·nH2O (2) and [Pd(fum)(pz)]
n
·3nH2O (3) {bipy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethene and pz = pyrazine} fumarate complexes are described in this work
as well their characterization by IR and 13C CPMAS NMR spectroscopies. TG curves showed that the compounds released organic ligands and lattice water molecules in the
temperature range of 46–491 °C. In all the cases, metallic palladium was identified as the final residue. 相似文献
13.
A Schiff base ligand containing thiocarbamide group of 4-phenyl-1-(4-methoxyl-1-phenylethylidene)thiosemicarbazide (HL) and
its three mononuclear metal complexes of ZnL2 (1), NiL2 (2), and CuL2 (3) have been synthesized. Elemental analysis, IR, and X-ray single crystal diffraction characterizations for the ligand and
the three complexes have been carried out. In the three complexes, the central metallic ions of Zn2+, Ni2+, and Cu2+ coordinate with two deprotonated ligands of L−, respectively. In 1, Zn2+ ion adopts a distorted tetrahedral geometry, while in 2 and 3, both the Ni2+ and Cu2+ ions possess distorted square planar configurations. For the four compounds, UV–Vis spectra have been measured and DFT calculations
at B3LYP/LANL2DZ level of theory prove that the electronic spectra of HL and 1 are corresponding with electronic transitions of n → π* and π → π* in the ligand itself and the electronic spectra of 2 and 3 are attributed to intraligand electronic transitions as well as d–d electronic transitions. Electrochemical investigations reveal that the different metal–ligand interactions have changed the
peak shapes and peak locations, which are corresponding with the DFT-B3LYP/LANL2DZ calculational results. Fluorescence spectra
measurements indicate that the ligand emits purple fluorescence and the complex 1 emits stronger blue fluorescence, while the complexes 2 and 3 quench fluorescence. The thermal analyses result show that the three complexes undergo two similar decomposition processes
because of their similar geometric configurations. 相似文献
14.
Yan-Hong Zhang Xue-Qiao Jia Gui-Ru Deng Qing-Lun Wang Guang-Ming Yang Dai-Zheng Liao 《Structural chemistry》2008,19(3):451-457
By using the macrocyclic oxamido-copper complex CuL (H2L = 2,3-dioxo-5,6:13,14-dibenzo-9,10-(O)cyclohexyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as precursor, two new trinuclear
complexes with the formulas [(CuL)2Mn(ClO4)2] (1) and [(CuL)2Co(ClO4)2] (2) have been synthesized and structurally characterized. H-bonds are found between the molecules, which link adjacent trinuclear
units together to form a unique one-dimensional structure. The temperature dependence of the magnetic susceptibility for the
complexes was analyzed by means of the Hamiltonian
leading to J = −14.66 cm−1 and J = −22.9 cm−1 for 1 and 2, respectively.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
W. Ferenc A. Dziewulska-Kułaczkowska J. Sarzyński B. Paszkowska 《Journal of Thermal Analysis and Calorimetry》2008,91(1):285-292
4-Chloro-2-methoxybenzoates of heavy lanthanides(III) and yttrium(III) were obtained as mono-, di-, tri-or tetrahydrates with
metal to ligand ratio of 1:3 and general formula Ln(C8H6ClO3)3·nH2O, where n=1 for Ln=Er, n=2 for Ln=Tb, Dy, Tm, Y, n=3 for Ln=Ho and n=4 for Yb and Lu. The complexes were characterized by elemental analysis, FTIR spectra, TG, DTA and DSC curves, X-ray diffraction
and magnetic measurements.
The carboxylate group appears to be a symmetrical bidentate chelating ligand. All complexes are polycrystalline compounds.
The values of enthalpy, ΔH, of the dehydration process for analysed complexes were also determined. The solubilities of heavy lanthanide(III) 4-chloro-2-methoxybenzoates
in water at 293 K are of the order of 10−4 mol dm−3. The magnetic moments were determined over the range of 76–303 K. The results indicate that there is no influence of the
ligand field of 4f electrons on lanthanide ions and the metal ligand bonding is mainly electrostatic in nature. 相似文献
16.
Solvothermal synthesis and structures of three novel heterometallic microporous coordination polymers assembled from 2-hydroxy-nicotinic acid 总被引:1,自引:0,他引:1
Hua Hong Zou Shu Hua Zhang Yu Xiao Chao Feng Yin Guang Wang 《Structural chemistry》2011,22(1):135-140
Abstract
Three novel heterometallic microporous coordination polymers {M(Hnico)3M′} n (1, M = Co, M′ = K; 2, M = Ni, M′ = K; 3, M = Co, M′ = Na, Hnico is the anion of 2-hydroxy-nicotinic acid, where the proton is transferred from the phenolate hydroxy group to the nitrogen atom of imine pyridine ring) were synthesized by hydrothermal reaction between M(Ac)2·4H2O, M′OH and a multifunctional organic aromatic H2nico ligand and characterized by IR spectrum, elemental analysis, raman spectrum and the single crystal X-ray diffractions. In complexes 1–3, the M2+ ions linked three different Hnico ligand formed [M(Hnico)3]− subunit which further interlinked the six-coordination M′+ cation constructed 3D network. The network topology of 1–3 can be simplified a rare 3D (4,4)-connected (41263) net. 相似文献17.
Four manganese(II) coordination compounds with bis(1-methylimidazol-2-yl)ketone (BIK) of general formula Mn(BIK)2X2 (X = Cl, Br, NO3, ClO4) were synthesized and characterized by elemental analysis, by UV–vis, and FTIR spectroscopies to be compared with the literature
data. Following our previous thermoanalytical studies on imidazole-substituted coordination compounds, the thermal behavior
of the synthesized Mn(II) complexes was investigated using TG and DTG techniques: the thermal profile is characterized by
three substantial consecutive releasing steps for all the three complexes and the releasing supposed behavior is confirmed
by EGA analysis performed by coupling the TG analyzer to an MS spectrometer. In particular, the first step is ascribed to
the release of the two anions, followed by the loss of four methyl groups (side chains of the ligand) and two bridge-carbonyl
groups. The residual tetra-imidazole manganese compound decomposes in a final step to give MnO as the final residue. Both
the initial decomposition temperatures and the kinetic rate constants associated to the first decomposition step indicated
a higher stability of the Mn(BIK)2Cl2 complex, the bromide complex being very close to the chloride one (first-step thermal stability: ClO4
− <NO3
− ≤Br− <Cl−). Finally, the three-dimensional diffusion reaction model (D3) was selected to describe the first decomposition step for
all the four complexes examined. 相似文献
18.
Metallosurfactant complexes of the type trans- [Co(DH)2(HA)X], where DH = Dimethyl glyoxime, HA = Hexadecyl amine and X = Cl−, Br−, I−, N3
−, NO2
− or SCN−, were synthesized and characterized by physico-chemical and spectroscopic methods. In addition, the single crystal X-ray
structure of the ionic complex trans-[Co(DH)2(HA)2][Co(DH)2(I)2)] is presented. The critical micelle concentration values of the complexes in ethanol were obtained by measuring the absorption
at 290 nm. Specific conductivity data (at 303–313 K) served for the evaluation of the thermodynamics of micellization
) \left( {\Updelta G^{0}_{{{\text{m}}}}, \Updelta H^{0}_{{{\text{m}}}}, \Updelta S^{0}_{\text{m}} } \right) . Steady-state photolysis, cyclic voltammetry and biological activities of the complexes were studied. The compounds were
tested for antimicrobial activity. 相似文献
19.
Derivative of 8-hydroxyquinoline i.e. Clioquinol is well known for its antibiotic properties, drug design and coordinating
ability towards metal ion such as Copper(II). The structure of mixed ligand complexes has been investigated using spectral,
elemental and thermal analysis. In vitro anti microbial activity against four bacterial species were performed i.e. Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Bacillus substilis and found that synthesized complexes (15–37 mm) were found to be significant potent compared to standard drugs (clioquinol
i.e. 10–26 mm), parental ligands and metal salts employed for complexation. The kinetic parameters such as order of reaction
(n = 0.96–1.49), and the energy of activation (E
a = 3.065–142.9 kJ mol−1), have been calculated using Freeman–Carroll method. The range found for the pre-exponential factor (A), the activation entropy (S* = −91.03 to−102.6 JK−1 mol−1), the activation enthalpy (H* = 0.380–135.15 kJ mol−1), and the free energy (G* = 33.52–222.4 kJ mol−1) of activation reveals that the complexes are more stable. Order of stability of complexes were found to be [Cu(A4)(CQ)OH] · 4H2O > [Cu(A3)(CQ)OH] · 5H2O > [Cu(A1)(CQ)OH] · H2O > [Cu(A2)(CQ)OH] · 3H2O 相似文献
20.
Adisorn Ratanaphan Tidarat Nhukeaw Pornvichai Temboot Kanidtha Hansongnern 《Transition Metal Chemistry》2012,37(2):207-214
A bidentate ligand, 5-chloro-2-(phenylazo)pyridine (Clazpy), and its two polypyridyl ruthenium(II) complexes, [Ru(Clazpy)2bpy]Cl2·7H2O (1) and [Ru(Clazpy)2phen]Cl2·8H2O (2), were synthesized and characterized. The DNA-binding properties of these complexes with DNA, the breast cancer susceptibility
gene 1 (BRCA1), and the pBIND plasmid DNA were probed by photocleavage, electronic absorption titration, ethidium bromide quenching, and
thermal denaturation. Both complexes were found to bind to the BRCA1 fragment through the intercalative mode into the base pairs of DNA, and the DNA-binding constants (Kb) for 1 and 2 were 7.0 × 104 M−1 and 5.1 × 105 M−1, respectively. In addition, both complexes enhanced the single-stranded cleavage of the plasmid DNA. Under comparable experimental
conditions, 2 cleaved DNA more effectively than 1, in a dose–response manner. The data indicated that the binding affinity of these two complexes to DNA was dependent on the
aromatic planarity and hydrophobicity of the intercalative polypyridyl ligand. 相似文献