ABSTRACT Starting from 5-bromo-N,N′-bis-(salicylidene)-o-tolidine (H2L) new complexes with Co(II)... more ABSTRACT Starting from 5-bromo-N,N′-bis-(salicylidene)-o-tolidine (H2L) new complexes with Co(II), Ni(II) and Cu(II) were synthesised and characterised. The features of complexes have been assigned from microanalytical, IR, UV–Vis–NIR and EPR spectra, magnetic data at room temperature as well as thermal analysis. IR data are in accordance with bischelate nature of the deprotonated ligand that coordinates through azomethinic nitrogen and phenolic oxygen. The electronic spectra display the characteristic pattern of tetrahedral stereochemistry for [CoL]·H2O complex and octahedral one for [NiL(OH2)2]·H2O complex. The electronic spectra correlated with magnetic susceptibility measurements indicate a square-planar surrounding for [ML] (M:Ni, Cu) species, while the EPR spectrum of copper complex sustains the proposed stereochemistry. The thermal analysis evidenced that thermal transformations are complex processes according to TG, DTA and DTG curves including (crystallization or coordination) water elimination, thermolyses and oxidative degradation of Schiff base. All these processes lead to the most stable metallic oxides as final product.
... with N,N-dimethylbiguanide as antibacterial agents Mihaela Badea • Ana-Maria Crasanda • Maria... more ... with N,N-dimethylbiguanide as antibacterial agents Mihaela Badea • Ana-Maria Crasanda • Mariana Carmen Chifiriuc • Luminita Marutescu • Veronica Lazar • Dana Marinescu • Rodica Olar CEEC-TAC1 Conference Special Issue Ó Akadémiai Kiadó, Budapest, Hungary 2012 ...
The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of... more The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of type [NiLCl2]·mH2O ((1) L:L1, m=6; (3) L:L2, m=4) or [CuLCl]nCl n ·mnH2O ((2) L:L1, m=6; (4) L:L2, m=4) are presented. The ligands L(1) and L(2) have been synthesised by template condensation of 3,6-diazaoctane-1,8-diamine or 1,2-diaminoethane with formaldehyde and 2-amino-4H-1,2,4-triazole. The bonding and stereochemistry of the
The natural proteins containing copper are involved in metal ions storage, oxygen or electrons tr... more The natural proteins containing copper are involved in metal ions storage, oxygen or electrons transport as well as in enzymatic reactions [1, 2]. These involvements of cop-per in physiological processes regulation have stimu-lated the synthesis of some complexes containing this ...
Results concerning the thermal behavior of three coordination compounds of Cu(II) with the ligand... more Results concerning the thermal behavior of three coordination compounds of Cu(II) with the ligand 2-amino-5-mercapto-1,3,4-thiadiazole are reported. Values of the non-isothermal kinetic parameters have been determined for some of the decomposition steps.
This paper reports an investigation of the thermal stabilities of the class of coordination compo... more This paper reports an investigation of the thermal stabilities of the class of coordination compounds containing lanthanide ions Ln(III) (Ln=La, Sm, Eu, Dy, Er), Co(II) ions and oxalate anions C2O 4 2– . The thermal decomposition steps were identified, and in some cases the values of the non-isothermal kinetic parameters were determined.
Summary This paper reports the investigation of the thermal stability of two new complexes with a... more Summary This paper reports the investigation of the thermal stability of two new complexes with allylacetoacetate anion, Cu(C7H9O3)2 (1) and Ni(C7H9O3)2(OH2)2 (2), respectively. The bonding and stereochemistry of the complexes have been characterized by IR, electronic and EPR spectra. The main decomposition steps were evidenced. The two complexes exhibit a different thermal behaviour. Thus, the copper complex suffers an oxidative
The reaction between NiCO3·Ni(OH)2, acrylic acid and ethylenediamine in a 2:4:1 molar ratio affor... more The reaction between NiCO3·Ni(OH)2, acrylic acid and ethylenediamine in a 2:4:1 molar ratio affords the binuclear complex, [Ni2(EDDP)2(H2O)2]·2H2O 1. The organic ligand, EDDP2− (the dianion of the ethylenediamine-N,N-dipropionic acid ligand), results from the addition of one amine group to the carbon–carbon double bonds of two acrylato ions. The crystal structure of 1 consists of neutral centrosymmetric entities, with the nickel
Introduction. The emergence of the antibiotic resistance and multi-resistance to antibiotics driv... more Introduction. The emergence of the antibiotic resistance and multi-resistance to antibiotics drives the acute necessity for the developing of new anti-infective strategies and the permanent changes of the disinfectants used in the hospital environment. The purpose of this study was to investigate by adapted disk diffusion techniques the antimicrobial potential of six (6) newly synthesized chemical compounds (derivatives from phenantroline
A series of new complexes with mixed ligands of the type M(4,4’-dipy)(C3H3O2)2(H2O)y ((1) M=Mn, y... more A series of new complexes with mixed ligands of the type M(4,4’-dipy)(C3H3O2)2(H2O)y ((1) M=Mn, y=2; (2) M=Ni, y=2; 4,4’-dipy: 4,4’-dipyridyl and C3H3O2 is acrylate anion) and respectively M2(4,4’-dipy)(C3H3O2)4(H2O)y ((3) M=Cu, y=0; (4) M=Zn, y=1). The modification evidenced in IR spectra was correlated with the presence of acrylate ion as unidentate in the case of complex (1) and as bidentate for
ABSTRACT Novel complexes of M2LCl4·nH2O type (M:Ni, n = 4; M:Cu, n = 3 and M:Zn, n = 0; L: ligand... more ABSTRACT Novel complexes of M2LCl4·nH2O type (M:Ni, n = 4; M:Cu, n = 3 and M:Zn, n = 0; L: ligand resulted from 1,4-phenylenediamine, 3,6-diazaoctane-1,8-diamine and formaldehyde one-pot condensation) were synthesized and characterised by microanalytical, ESI–MS, IR, UV–Vis, 1H NMR and EPR spectra, magnetic data at room temperature and molar conductivities as well. The electrochemical behaviour of complexes was investigated by cyclic voltammetry. Simultaneous TG/DTA measurements were performed in order to evidence the thermal behaviour of the obtained complexes. Processes such as water elimination, fragmentation and oxidative degradation of the organic ligand as well as chloride elimination occurred during thermal decomposition. The antimicrobial assays demonstrate that the compounds exhibited good antibacterial activity, especially against S. aureus and E. coli strains, the most active being the copper(II) complex, which also exhibited the most prominent anti-biofilm effect, suggesting its potential use for the development of new antimicrobial agents. The biological activity was correlated with log P ow values. All complexes disrupt the membrane integrity of HCT 8 tumour cells.
ABSTRACT New complexes ML(CNS)·nH2O [M = Ni, n = 0.5; M = Cu, n = 4.5; M = Zn, n = 0.5, HL: 6-mer... more ABSTRACT New complexes ML(CNS)·nH2O [M = Ni, n = 0.5; M = Cu, n = 4.5; M = Zn, n = 0.5, HL: 6-mercapto-(1,4,8,11-tetraazaundecanyl)-6-carboxylic acid)] have been synthesised, chemical analysed, and characterised by different spectroscopic techniques (IR, UV–Vis–NIR, 1H NMR, EPR, ESI–MS), and magnetic measurements. Based on the IR spectra a dinuclear structure with the 1,3-CSN coordination was proposed for Ni(II) and Cu(II) complexes. The dinuclear structure of Cu(II) complex is also consistent with both magnetic behaviour and EPR spectrum. According to TG, DTG and DTA curves the thermal transformations are complex processes, including dehydration, Mannich base oxidative degradation and thiocyanate decomposition. The final product of decomposition is the most stable metallic oxide, as XRD data indicates. The new complexes were also screened for their microbicidal and antibiofilm properties.
ABSTRACT Starting from 5-bromo-N,N′-bis-(salicylidene)-o-tolidine (H2L) new complexes with Co(II)... more ABSTRACT Starting from 5-bromo-N,N′-bis-(salicylidene)-o-tolidine (H2L) new complexes with Co(II), Ni(II) and Cu(II) were synthesised and characterised. The features of complexes have been assigned from microanalytical, IR, UV–Vis–NIR and EPR spectra, magnetic data at room temperature as well as thermal analysis. IR data are in accordance with bischelate nature of the deprotonated ligand that coordinates through azomethinic nitrogen and phenolic oxygen. The electronic spectra display the characteristic pattern of tetrahedral stereochemistry for [CoL]·H2O complex and octahedral one for [NiL(OH2)2]·H2O complex. The electronic spectra correlated with magnetic susceptibility measurements indicate a square-planar surrounding for [ML] (M:Ni, Cu) species, while the EPR spectrum of copper complex sustains the proposed stereochemistry. The thermal analysis evidenced that thermal transformations are complex processes according to TG, DTA and DTG curves including (crystallization or coordination) water elimination, thermolyses and oxidative degradation of Schiff base. All these processes lead to the most stable metallic oxides as final product.
... with N,N-dimethylbiguanide as antibacterial agents Mihaela Badea • Ana-Maria Crasanda • Maria... more ... with N,N-dimethylbiguanide as antibacterial agents Mihaela Badea • Ana-Maria Crasanda • Mariana Carmen Chifiriuc • Luminita Marutescu • Veronica Lazar • Dana Marinescu • Rodica Olar CEEC-TAC1 Conference Special Issue Ó Akadémiai Kiadó, Budapest, Hungary 2012 ...
The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of... more The investigations concerning the thermal behaviour of a series of Ni(II) and Cu(II) complexes of type [NiLCl2]·mH2O ((1) L:L1, m=6; (3) L:L2, m=4) or [CuLCl]nCl n ·mnH2O ((2) L:L1, m=6; (4) L:L2, m=4) are presented. The ligands L(1) and L(2) have been synthesised by template condensation of 3,6-diazaoctane-1,8-diamine or 1,2-diaminoethane with formaldehyde and 2-amino-4H-1,2,4-triazole. The bonding and stereochemistry of the
The natural proteins containing copper are involved in metal ions storage, oxygen or electrons tr... more The natural proteins containing copper are involved in metal ions storage, oxygen or electrons transport as well as in enzymatic reactions [1, 2]. These involvements of cop-per in physiological processes regulation have stimu-lated the synthesis of some complexes containing this ...
Results concerning the thermal behavior of three coordination compounds of Cu(II) with the ligand... more Results concerning the thermal behavior of three coordination compounds of Cu(II) with the ligand 2-amino-5-mercapto-1,3,4-thiadiazole are reported. Values of the non-isothermal kinetic parameters have been determined for some of the decomposition steps.
This paper reports an investigation of the thermal stabilities of the class of coordination compo... more This paper reports an investigation of the thermal stabilities of the class of coordination compounds containing lanthanide ions Ln(III) (Ln=La, Sm, Eu, Dy, Er), Co(II) ions and oxalate anions C2O 4 2– . The thermal decomposition steps were identified, and in some cases the values of the non-isothermal kinetic parameters were determined.
Summary This paper reports the investigation of the thermal stability of two new complexes with a... more Summary This paper reports the investigation of the thermal stability of two new complexes with allylacetoacetate anion, Cu(C7H9O3)2 (1) and Ni(C7H9O3)2(OH2)2 (2), respectively. The bonding and stereochemistry of the complexes have been characterized by IR, electronic and EPR spectra. The main decomposition steps were evidenced. The two complexes exhibit a different thermal behaviour. Thus, the copper complex suffers an oxidative
The reaction between NiCO3·Ni(OH)2, acrylic acid and ethylenediamine in a 2:4:1 molar ratio affor... more The reaction between NiCO3·Ni(OH)2, acrylic acid and ethylenediamine in a 2:4:1 molar ratio affords the binuclear complex, [Ni2(EDDP)2(H2O)2]·2H2O 1. The organic ligand, EDDP2− (the dianion of the ethylenediamine-N,N-dipropionic acid ligand), results from the addition of one amine group to the carbon–carbon double bonds of two acrylato ions. The crystal structure of 1 consists of neutral centrosymmetric entities, with the nickel
Introduction. The emergence of the antibiotic resistance and multi-resistance to antibiotics driv... more Introduction. The emergence of the antibiotic resistance and multi-resistance to antibiotics drives the acute necessity for the developing of new anti-infective strategies and the permanent changes of the disinfectants used in the hospital environment. The purpose of this study was to investigate by adapted disk diffusion techniques the antimicrobial potential of six (6) newly synthesized chemical compounds (derivatives from phenantroline
A series of new complexes with mixed ligands of the type M(4,4’-dipy)(C3H3O2)2(H2O)y ((1) M=Mn, y... more A series of new complexes with mixed ligands of the type M(4,4’-dipy)(C3H3O2)2(H2O)y ((1) M=Mn, y=2; (2) M=Ni, y=2; 4,4’-dipy: 4,4’-dipyridyl and C3H3O2 is acrylate anion) and respectively M2(4,4’-dipy)(C3H3O2)4(H2O)y ((3) M=Cu, y=0; (4) M=Zn, y=1). The modification evidenced in IR spectra was correlated with the presence of acrylate ion as unidentate in the case of complex (1) and as bidentate for
ABSTRACT Novel complexes of M2LCl4·nH2O type (M:Ni, n = 4; M:Cu, n = 3 and M:Zn, n = 0; L: ligand... more ABSTRACT Novel complexes of M2LCl4·nH2O type (M:Ni, n = 4; M:Cu, n = 3 and M:Zn, n = 0; L: ligand resulted from 1,4-phenylenediamine, 3,6-diazaoctane-1,8-diamine and formaldehyde one-pot condensation) were synthesized and characterised by microanalytical, ESI–MS, IR, UV–Vis, 1H NMR and EPR spectra, magnetic data at room temperature and molar conductivities as well. The electrochemical behaviour of complexes was investigated by cyclic voltammetry. Simultaneous TG/DTA measurements were performed in order to evidence the thermal behaviour of the obtained complexes. Processes such as water elimination, fragmentation and oxidative degradation of the organic ligand as well as chloride elimination occurred during thermal decomposition. The antimicrobial assays demonstrate that the compounds exhibited good antibacterial activity, especially against S. aureus and E. coli strains, the most active being the copper(II) complex, which also exhibited the most prominent anti-biofilm effect, suggesting its potential use for the development of new antimicrobial agents. The biological activity was correlated with log P ow values. All complexes disrupt the membrane integrity of HCT 8 tumour cells.
ABSTRACT New complexes ML(CNS)·nH2O [M = Ni, n = 0.5; M = Cu, n = 4.5; M = Zn, n = 0.5, HL: 6-mer... more ABSTRACT New complexes ML(CNS)·nH2O [M = Ni, n = 0.5; M = Cu, n = 4.5; M = Zn, n = 0.5, HL: 6-mercapto-(1,4,8,11-tetraazaundecanyl)-6-carboxylic acid)] have been synthesised, chemical analysed, and characterised by different spectroscopic techniques (IR, UV–Vis–NIR, 1H NMR, EPR, ESI–MS), and magnetic measurements. Based on the IR spectra a dinuclear structure with the 1,3-CSN coordination was proposed for Ni(II) and Cu(II) complexes. The dinuclear structure of Cu(II) complex is also consistent with both magnetic behaviour and EPR spectrum. According to TG, DTG and DTA curves the thermal transformations are complex processes, including dehydration, Mannich base oxidative degradation and thiocyanate decomposition. The final product of decomposition is the most stable metallic oxide, as XRD data indicates. The new complexes were also screened for their microbicidal and antibiofilm properties.
Uploads