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1.
Valentina Uivarosi Mihaela Badea Rodica Olar Dana Marinescu Teodor Octavian Nicolescu George Mihai Nitulescu 《Journal of Thermal Analysis and Calorimetry》2011,105(2):645-650
Three new complexes with ligands belong to the fluoroquinolone class having the general formula [RuL2Cl2]Cl nH2O ((1) L: norfloxacin (nf), n = 4; (2) L: ciprofloxacin (cp), n = 3; (3) L: enrofloxacin (enro), n = 5) were synthesized and characterized by chemical analysis UV–Vis and IR spectroscopy. In all complexes fluoroquinolone
derivative acts as bidentate chelate ligand. The thermal behavior steps were investigated in synthetic air flow. The thermal
transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative degradation,
as well as RuCl3 conversion in RuO2. 相似文献
2.
Rodica Olar Michaela Badea E. Cristurean C. Parnau D. Marinescu 《Journal of Thermal Analysis and Calorimetry》2006,84(1):53-58
The complexes of the type M(HDMBG)2(CH3COO)2·nH2O ((1)
M:Mn, n=1.5; (2)
M:Ni, n=0; (3)
M:Cu, n=2; (4)
M:Zn, n=2; DMBG: N,N-dimethylbiguanide)
present in vitro antimicrobial activity. The thermal analysis has evidenced
the thermal intervals of stability and also the thermodynamics effects that
accompany them. The different nature of the ligands generates a different
thermal behaviour for the complexes. The thermal transformations are complex
processes according to TG and DTG curves including dehydration, oxidative
condensation of –C=N– units as well as thermolysis processes.
The final products of decomposition are the most stable metal oxides. 相似文献
3.
Rodica Olar Mihaela Badea Dana Marinescu Veronica Lazar Carmen Chifiriuc 《Journal of Thermal Analysis and Calorimetry》2009,97(2):721-727
Schiff bases obtained by the condensation of 2-amino-5-mercapto-1,3,4-thiadiazole with 2,4-pentandione or 1-phenyl-1,3-butandione
were synthesized and characterized in order to obtain polydentate ligands HL1 and HL2, respectively. The complexes with these ligands of the type M(L)Cl·nH2O [(1) M:Ni, L:L1, n = 0.5; (3) M:Ni, L:L2, n = 0.5]; [(2) M:Cu, L:L1, n = 1; (4) M:Cu, L:L2, n = 0] were also synthesized and characterized. The modifications evidenced in IR spectra of complexes were correlated with
the presence of monodeprotonate Schiff bases. The electronic spectra display the characteristic pattern of square-planar stereochemistry.
The in vitro qualitative and quantitative antimicrobial activity assays showed that the new complexes exhibited variable antimicrobial
activity. The thermal analyses have evidenced the thermal intervals of stability and also the thermodynamic effects that accompany
them. Schiff bases and complexes have a similar thermal behaviour. Processes as water elimination, melting, chloride anion
removal as well as oxidative degradation of the organic ligands were observed. 相似文献
4.
Güne? Süheyla Kürk?üo?lu Okan Zafer Ye?ilel ?lkan Kavlak Orhan Büyükgüng?r 《Structural chemistry》2008,19(6):879-888
Polymeric tetracyanonickelate complexes of the type [M(H2O)(2mpz)Ni(μ-CN)4]
n
(2mpz = 2-methylpyrazine, M = Mn(II) (1) or Cd(II) (2)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal, and elemental analyses. The crystal structure
of supramolecular [Cd(H2O)(2mpz)Ni(CN)4]
n
complex has been determined by X-ray single crystal diffraction. It crystallizes in the orthorhombic system, space group
Pnma. The structure consists of corrugated and cyanide-bridged polymeric two-dimensional networks. In the Hofmann-type complexes,
the coordination environment of the M(II) ions can be described as distorted octahedral geometry, whereas around the Ni(II)
center has square planar geometry. The spectral features suggest that the 2mpz is coordinated to metal ions of the adjacent
layers of [M-Ni(CN)4]
n
as monodentate ligand. The thermal decomposition of these complexes takes place in three stages: (i) dehydration, (ii) decomposition
of the 2-methylpyrazine ligands, and (iii) release of the CN groups and burning of organic residue. 相似文献
5.
《应用有机金属化学》2017,31(10)
New mixed ligand complexes of transition metals were synthesized from a Schiff base (L1) obtained by the condensation reaction of oxamide and furfural as primary ligand and 2,2′‐bipyridine (L2) as secondary ligand. The ligands and their metal complexes were studied using various spectroscopic methods. Also thermal analyses were conducted. The mixed ligand complexes were found to have formulae [M(L1)(L2)]Clm ⋅n H2O (M = Cr(III) and Fe(III): m = 3, n = 0; M = Cu(II) and Cd(II): m = 2, n = 1; M = Mn(II), Co(II), Ni(II) and Zn(II): m = 2, n = 0). The resultant data revealed that the metal complexes have octahedral structure. Also, the mixed ligand complexes are electrolytic. The biological and anticancer activities of the new compounds were tested against breast cancer (MCF‐7) and colon cancer (HCT‐116) cell lines. The results showed high activity for the synthesized compounds. 相似文献
6.
R. Olar M. Badea N. Stanica E. Cristurean D. Marinescu 《Journal of Thermal Analysis and Calorimetry》2005,82(2):417-422
Summary The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of type [MLCln]·mH2O ((1) M:Ni, L:L(1), n=1, m=2; (2) M:Cu, L:L(2), n=1, m=2; (3) M:Ni, L:L(3), n=2, m=0; (4) M:Cu, L:L(3), n=1, m=2) are presented in this paper. The ligands L(1)-L(3) have been synthesised by template condensation of 1,2-diaminoethane
with formaldehyde and 2-amino-1,3,4-thiadiazole-5-thiole or 2-acetamino-1,3,4-thiadiazole-5-sulfonamide. The bonding and stereochemistry
of the complexes have been characterised by IR, electronic and magnetic studies at room temperature. The thermal behaviour
provided confirmation of the complex composition as well as the number and the nature of water molecules and the intervals
of thermal stability. The different nature of the ligands and/or the metallic ions generates a different thermal behaviour
for complexes. The complexes do not show biological activity against HIV virus. 相似文献
7.
Mihaela Badea Rodica Olar Dana Marinescu Valentina Uivarosi Daniela Iacob 《Journal of Thermal Analysis and Calorimetry》2009,97(2):735-739
A series of new complexes with mixed ligands of the type RuL2(DMSO)
m
Cl3·nH2O ((1) L: norfloxacin (nf), m = 1, n = 1; (2) L: ciprofloxacin (cp), m = 2, n = 2; (3) L: ofloxacin (of), m = 1, n = 1; (4) L: enrofloxacin (enro), m = 0.5, n = 4; DMSO: dimethylsulfoxide) were synthesised and characterised by chemical analysis and IR data. In all complexes both
fluoroquinolone derivative and DMSO act as unidentate. The thermal behaviour steps were investigated in synthetic air flow.
The thermal transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative
and DMSO degradation respectively. The final product of decomposition is ruthenium (IV) oxide. 相似文献
8.
C. Menapace I. Lonardelli A. Molinari 《Journal of Thermal Analysis and Calorimetry》2010,101(3):815-821
New complexes of type [Cu(HTBG)2]Cl2 (1), [Cu(TBG)2]·3H2O (2) and [CuL]·nH2O (3) L:L1, n = 2 and (4) L:L2, n = 1 (HTBG: 2-tolylbiguanide, L1 and L2: ligands resulted from 2-tolylbiguanide, ammonia/hydrazine and formaldehyde one pot condensation) were synthesised and characterised.
The features of complexes have been assigned from microanalytical, IR and UV–Vis data. Redox behaviour was established by
cyclic voltammetry. The in vitro qualitative and quantitative antimicrobial activity assays showed that the complexes exhibited
variable antimicrobial activity against Gram-negative and Gram-positive strains isolated from the hospital environment. The
thermal analyses have evidenced the thermal intervals of stability and also the thermodynamic effects that accompany them.
After water elimination, complexes have a similar thermal behaviour. Processes as water elimination, melting, chloride anion
removal as well as oxidative degradation of the organic ligands were observed. The final product of decomposition was copper
(II) oxide. 相似文献
9.
Coordination compounds of Mn (II), Fe (III), Co (II), Ni (II), Cu (II) and Cd (II) ions were synthesized from reaction with Schiff base ligand 4,6‐bis((E)‐(2‐(pyridin‐2‐yl)ethylidene)amino)pyrimidine‐2‐thiol (HL) derived from the condensation of 4,6‐diaminopyrimidine‐2‐thiol and 2‐(pyridin‐2‐yl)acetaldehyde. Microanalytical data, magnetic susceptibility, infrared and 1H NMR spectroscopies, mass spectrometry, molar conductance, powder X‐ray diffraction and thermal decomposition measurements were used to determine the structure of the prepared complexes. It was found that the coordination between metal ions and bis‐Schiff base ligand was in a molar ratio of 1:1, with formula [M (HL)(H2O)2] Xn (M = Mn (II), Co (II), Ni (II), Cu (II) and Cd (II), n = 2; Fe (III), n = 3). Diffuse reflectance spectra and magnetic susceptibility measurements suggested an octahedral geometry for the complexes. The coordination between bis‐Schiff base ligand and metal ions was through NNNN donor sites in a tetradentate manner. After preparation of the complexes, biological studies were conducted using Gram‐positive (B. subtilis and S. aureus) and Gram‐negative (E. coli and P. aeruginosa) organisms. Metal complexes and ligand displayed acceptable microbial activity against both types of bacteria. 相似文献
10.
Mihaela Badea Rodica Olar Valentina Uivarosi Dana Marinescu Victoria Aldea Stefania Felicia Barbuceanu George Mihai Nitulescu 《Journal of Thermal Analysis and Calorimetry》2011,105(2):559-564
Two new complexes having general formula VOL2·nH2O [(1) L: 5-hydroxyflavone, n = 1; (2) L: chrysin, n = 4] were synthesized and characterized. Based on IR and electronic data we concluded that studied flavones act as bidentate
ligands in complexes with metallic ion coordinated in a square-pyramidal stereochemistry. The thermal analysis (TG, DTA) elucidated
the composition and also the number and nature of the water molecules. The thermal behavior also indicated strong interactions
between oxovanadium (IV) and these oxygen donor ligands. 相似文献
11.
Sayed M. Abdallah Gehad G. Mohamed M.A. Zayed Mohsen S. Abou El-Ela 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,73(5):833-840
New Schiff base (H2L) ligand is prepared via condensation of o-phthaldehyde and 2-aminophenol. The metal complexes of Cr(III), Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with the ligand are prepared in good yield from the reaction of the ligand with the corresponding metal salts. They are characterized based on elemental analyses, IR, solid reflectance, magnetic moment, electron spin resonance (ESR), molar conductance, 1H NMR and thermal analysis (TGA). From the elemental analyses data, the complexes are proposed to have the general formulae [M(L)(H2O)n]·yH2O (where M = Mn(II) (n = 0, y = 1), Fe(II) (n = y = 0), Co(II) (n = 2, y = 0), Ni(II) (n = y = 2), Cu(II) (n = 0, y = 2) and Zn(II) (n = y = 0), and [MCl(L)(H2O)]·yH2O (where M = Cr(III) and Fe(III), y = 1–2). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that H2L is coordinated to the metal ions in a bi-negatively tetradentate manner with ONNO donor sites of the azomethine N and deprotonated phenolic-OH. This is supported by the 1H NMR and ESR data. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral (Cr(III), Fe(III), Co(II) and Ni(II) complexes), tetrahedral (Mn(II), Fe(II) and Zn(II) complexes) and square planar (Cu(II) complex). The thermal behaviour of these chelates is studied and the activation thermodynamic parameters, such as, E*, ΔH*, ΔS* and ΔG* are calculated from the DrTGA curves using Coats-Redfern method. The parent Schiff base and its eight metal complexes are assayed against two fungal and two bacterial species. With respect to antifungal activity, the parent Schiff base and four metal complexes inhibited the growth of the tested fungi at different rates. Ni(II) complex is the most inhibitory metal complex, followed by Cr(III) complex, parent Schiff base then Co(II) complex. With regard to bacteria, only two of the tested metal complexes (Mn(II) and Fe(II)) weakly inhibit the growth of the two tested bacteria. 相似文献
12.
Mihaela Badea Rodica Olar Dana Marinescu Valentina Uivarosi Victoria Aldea Teodor Octavian Nicolescu 《Journal of Thermal Analysis and Calorimetry》2010,99(3):823-827
A series of new complexes of the type VO(OH)L·nH2O ((1) L: fisetin, n = 3; (2) L: quercetin, n = 2; (3) L: morin, n = 4) were synthesised and characterised by analytical as well as IR and electronic data. The modification evidenced in IR
spectra was correlated with the presence of flavonoid as bidentate in all complexes. The electronic reflectance spectra showed
the d–d transition characteristic for the square-pyramidal stereochemistry of vanadium (IV) ion. The thermal analysis (TG, DTA) in
synthetic air flow elucidated the composition and also the number and nature of the water molecules. The TG curves show three
well-separated thermal events. The first corresponds to the water loss at lower temperatures, which is followed by flavonoid
derivative decomposition and pyrolysis at higher temperatures. The final product is vanadium (V) oxide. 相似文献
13.
Two novel amino acids imine ligands (H2L1 and H2L2) have been synthesized using green condensation reaction from 2‐[3‐Amino‐5‐(2‐hydroxy‐phenyl)‐5‐methyl‐1,5‐dihydro‐[1, 2, 4]triazol‐4‐yl]‐3‐(1H‐indol‐3‐yl)‐propionic acid with benzaldehyde/p‐flouro benzaldehyde (1:1 molar ratio) in the presence of lemon juice as a natural acidic catalyst in aqueous medium. Their transition metal complexes have been prepared in a molar ratio (1:1). Characterization of the ligands and complexes using elemental analysis, spectroscopic studies, 1HNMR, 13CNMR, and thermal analysis has been reported. E*, ΔH*, ΔS* and ΔG* thermodynamic parameters, were calculated to throw more light on the nature of changes accompanying the thermal decomposition process of these complexes. The molar conductance measurement of metal complexes showed nonelectrolyte behavior. The metal complexes of the two ligands have tetrahedral geometry with a general molecular structure [M(H2L)Xn], where [(M = Mn (II), Co (II), Cu (II) and Zn (II), X = Cl, n = 2]; M = VO (II), X = SO4, n = 1] for H2L1. [M = Co (II), Cu (II), Zn (II)] for H2L2. Antibacterial activity of the complexes against (Bacillis subtilis, Micrococcus luteus, Escherichia coli), also antifungal activity against (Aspergillus niger, Candida Glabarta, Saccharomyces cerevisiae) have been screened. The results showed that all complexes have antimicrobial activity higher than free ligands. Molecular docking studies results showed that, all the synthesized compounds having minimum binding energy and have good affinity toward the active pocket, thus, they may be considered as good inhibitor of targeting PDB code: 1SC7 (Human DNA Topo‐isomerase I). 相似文献
14.
Two new complexes with formula VOL2·nH2O ((1) L: 4′,5,7-trihydroxyflavone-7-rhamnoglucoside (naringin), n = 8; (2) L: 3′,4′,7-tris[O-(2-hydroxyethyl)]rutin (troxerutin), n = 0) were synthesised and characterised. The IR and UV–Vis spectral data indicate that these flavones act as bidentate chelating
ligands and generate VO(II) complexes with a square-pyramidal stereochemistry. The thermal analysis (TG, DTA) elucidated the
composition and also the number and nature of the water molecules. The thermal behavior indicates also a strong interaction
between oxovanadium (IV) and these oxygen donor ligands. 相似文献
15.
Mihaela Badea Rodica Olar Dana Marinescu Valentina Uivarosi Teodor Octavian Nicolescu Daniela Iacob 《Journal of Thermal Analysis and Calorimetry》2010,99(3):829-834
A series of new complexes with mixed ligands of the type RuL
m
(DMSO)
n
Cl3·xH2O ((1) L: oxolinic acid (oxo), m = 1, n = 0, x = 4; (2) L: pipemidic acid (pip), m = 2, n = 1, x = 2; (3) L: enoxacin (enx), m = 2, n = 1, x = 0; (4) L: levofloxacin (levofx), m = 2, n = 2, x = 8; DMSO: dimethylsulfoxide) were synthesized and characterized by chemical analysis, IR and electronic data. Except oxolinic
acid that behaves as bidentate, the other ligands (quinolone derivatives and DMSO) act as unidentate. Electronic spectra are
in accordance with an octahedral stereochemistry. The thermal analysis (TG, DTA) in synthetic air flow elucidated the composition
and also the number and nature of both water and DMSO molecules. The TG curves show 3–5 well-separated thermal steps. The
first corresponds to the water and/or DMSO loss at lower temperatures followed either by quinolone thermal decomposition or
pyrolisys at higher temperatures. The final product is ruthenium(IV) oxide. 相似文献
16.
Transition
metal complexes of heterocyclic Schiff base 总被引:1,自引:0,他引:1
M. M. Omar G. G. Mohamed A. M. M. Hindy 《Journal of Thermal Analysis and Calorimetry》2006,86(2):315-325
Metal complexes of Schiff base derived from
2-furancarboxaldehyde and 2-aminobenzoic acid (HL) are reported and characterized
based on elemental analyses, IR, 1H NMR, UV-Vis,
solid reflectance, magnetic moment, molar conductance and thermal analysis.
The ligand dissociation as well as the metal-ligand stability constants have
been calculated pH-metrically at 25°C and ionic strength μ=0.1 (1 M
NaCl). The complexes are found to have the formulae [M(HL)2](X)n·yH2O
(where M=Fe(III) (X=Cl, n=3, y=4), Co(II)
(X=Cl, n=y=2), Ni(II) (X=Cl, n=y=2), Cu(II)
(X=Cl, n=y=2) and Zn(II) (X=AcO, n=y=2)) and [UO2(L)2]·2H2O. The thermal behaviour of these chelates is studied and the
activation thermodynamic parameters are calculated using Coats-Redfern method.
The ligand and its metal complexes show a biological activity against some
bacterial species. 相似文献
17.
S. Vairam T. Premkumar S. Govindarajan 《Journal of Thermal Analysis and Calorimetry》2010,101(3):979-985
Hydrazine forms two different types of complexes with divalent metal ions and pyromellitic acid (H4pml) in aqueous medium: (i) hydrazinium complexes of formulae, (N2H5)2M(pml)·xH2O, where x = 3 for M=Ni and x = 4 for M=Co or Zn, and (N2H5)2Mn(H2pml)2, at pH 4.5, (ii) neutral hydrazine complexes with formulae, M2(pml)(N2H4)
n
·xH2O where M=Co or Ni when n = 4 and x = 5 or 4 and M=Zn or Cd when n = 2, and x = 4 or 3 at pH 7, and M(H2pml)(N2H4)·xH2O where x = 4; M=Cu and x = 0; M=Hg, at pH 3, 7.5, respectively. All the complexes are insoluble in water, alcohol and ether. The N–N stretching frequency
(990–1,007 cm−1 for coordinated hydrazinium ion and 956–985 cm−1 for bridged neutral hydrazine) indicates the nature of hydrazine present in the complexes. Simultaneously TG-DTA analysis
indicates that hydrazinium complexes undergo dehydration and dehydrazination in a single step endothermally in the range of
289–300 °C whereas neutral hydrazine complexes undergo endothermic dehydration (~100 °C) followed by exothermic dehydrazination
in the temperature range, 253–332 °C. The anhydrous metal carboxylates further decompose exothermally to leave the respective
metal oxides or metal carbonates except zinc, which gives its oxalate as the end product. X-ray powder patterns indicate that
even the complexes with the same formulation possess no isomorphism. 相似文献
18.
S. B. Kalia G. Kaushal K. Lumba Priyanka 《Journal of Thermal Analysis and Calorimetry》2008,91(2):609-613
The thermal decomposition studies on 4-methylpiperazine-1-carbodithioic acid ligand (4-MPipzcdtH) and its complexes, viz.
[M(4-MPipzcdtH)n](ClO4)n (M=Fe(III) when n=3; M=Co(II), Cu(II) when n=2) and [Zn(4-MPipzcdtH)2]Cl2 have been carried out using non-isothermal techniques (TG and DTA). Initial decomposition temperatures (IDT), indicate that
thermal stability is influenced by the change of central metal ion. Free acid ligand exhibits single stage decomposition with
a sharp DTA endotherm. Complexes, [M(4-MPipzcdtH)n](ClO4)n undergo single stage decomposition with detonation and give rise to very sharp exothermic DTA curves while the complex [Zn(4-MPipzcdtH)2]Cl2 shows three-stage decomposition patterns.
The kinetic and thermodynamic parameters, viz. the energy of activation E, the frequency factor A, entropy of activation S
and specific rate constant k, etc. have been evaluated from TG data using Coats and Redfern equation. Based upon the results
of the differential thermal analysis study, the [M(4-MPipzcdtH)n](ClO4)n complexes have been found to possess characteristic of high energy materials. 相似文献
19.
G. J. Kharadi 《Journal of Thermal Analysis and Calorimetry》2012,107(2):651-659
Four copper(II) new mix ligand complexes of the coumarin derivative (A1 = 7-hydroxy-10,11-dihydroindeno[5,4-c]chromen-6(9H)-one, A2 = 2-bromo-7-hydroxy-10,11- dihydroindeno[5,4-c]chromen-6(9H)-one, A3 = 7-hydroxy-4-methoxy-10,11-dihydroindeno[5,4-c]chromen-6(9H)-one, and A4 = 5-hydroxy-8,9-dihydrobenzo[f]indeno[5,4-c]chromen-4(7H)-one) and 1,10-Phenanthroline have been synthesized. The structural
interpretations were confirmed from elemental analyses, magnetic susceptibility and FAB mass spectral, as well as from IR
spectral studies. From the analytical, spectroscopic, and thermal data, the stoichiometry of the mentioned complexes was found
to be 1:1:1 (coumarin ligand:copper metal:1,10-Phenanthroline). The thermal stabilities of these complexes were studied by
thermogravimetric (TG/DTG) and the decomposition steps of these four complexes are investigated. Kinetic parameters such as
order of reaction (n) and the energy of activation (E
a) were calculated using Freeman–Carroll method. The pre-exponential factor (A), the activation entropy (S*), the activation enthalpy (H*), and the free energy of activation (G*) were calculated using Horowitz–Matzger equations. Based on the E
a values, the thermal stabilities of complexes in the decreasing order are Cu(II)-2 > Cu(II)-3 > Cu(II)-4 > Cu(II)-1. 相似文献
20.
F. Doğan M. Ulusoy Ö. F. Öztürk İ. Kaya B. Salih 《Journal of Thermal Analysis and Calorimetry》2009,96(1):267-276
The thermal decomposition kinetics of sterically hindered salen type ligand (L) and its metal complexes [M=Co(II), Ni(II), Cu(II)] were investigated by thermogravimetric analysis. A direct insertion probe-mass spectrometer (DIP-MS)
was used for the characterization of metal complexes of L and all fragmentations and stable ions were characterized. The thermogravimetry and differential thermogravimetry (TG-DTG)
plots of salen type salicylaldimine ligand and complexes showed a single step.
The kinetic analysis of thermogravimetric data was performed by using the invariant kinetic parameter method (IKP). The values
of the invariant activation energy, E
inv and the invariant pre-exponential factor, A
inv, were calculated by using Coats-Redfern (CR) method. The thermal stabilities and activation energies of metal complexes of
sterically hindered salen type ligand (L) were found as Co(II)>Cu(II)>Ni(II)>L and E
Cu>E
Ni>E
Co>L. Also, the probabilities of decomposition functions were investigated. The diffusion functions (D
n) are most probable for the thermal decomposition of all complexes. 相似文献