Thermal behavior of some new triazole derivative complexes

A series of new complexes with mixed ligands of the type [ML(C₃H₃O₂)₂]·nH₂O (((1) M=Mn, n=1; (2) M=Co(II), n=2; (3) M=Ni(II), n=4; (4) M=Cu(II), n=1.5; (5) M=Zn(II), n=0; L=3-amino-1,2,4-triazole and (C₃H₃O₂)=acrylate anion) were synthesized and characterised by chemical analysis and IR data. In all complexes the 3-amino-1,2,4-triazole acts as bridge while the acrylate acts as bidentate ligand except for complex (5) where it is found as unidentate. The thermal behaviour steps were investigated in nitrogen flow. The thermal transformations are complex processes according to TG and DTG curves including dehydration, acrylate ion and 3-amino-1,2,4-triazole degradation respectively. The final products of decomposition are the most stable metal oxides, except for complex (4) that leads to metallic copper.     

Some new acrylate complexes as a criterion in their selection for further co-polymerization reaction

Summary This paper reports the investigation of the thermal stability of a series of new complexes with mixed ligands of the type M(phen)(C₃H₃O₂)₂(H₂O)_y ((1) M=Mn, y=0; (2) M=Ni, y=2; (3) M=Cu, y=1; (4) M=Zn, y=2; phen=phenanthroline and C₃H₃O₂ is acrylate anion). The thermal behaviour steps were investigated. The thermal transformations are complex processes according to TG and DTG curves including dehydration, oxidative condensation of acrylate and thermolysis processes. The final products of decomposition are the most stable metal oxides.     

Thermal behavior of some new complexes bearing ligands with polymerisable groups

This paper reports the investigation of the thermal stability of a series of new complexes with mixed ligands of the type M(dipy)(C₃H₃O₂)₂(H₂O)_y ((1) M: Mn, y=1; (2) M: Ni, y=2; (3) M: Cu, y=1; (4) M: Zn, y=2; dipy: 2,2’-dipyridine and C₃H₃O₂ is acrylate anion). The thermal behaviour steps were investigated. The thermal transformations are complex processes according to TG and DTG curves including dehydration, oxidative condensation of acrylate and thermolysis processes. The final products of decomposition are the most stable metal oxides.     

Thermal stability of some new complexes bearing ligands with polymerizable groups

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 others complexes. The electronic reflectance spectra showed the d–d transition for complex (1) and (2) characteristic for the octahedral surrounding while the spectrum for complex (3) have the characteristic pattern for square-pyramidal stereochemistry. The thermal behaviour steps were investigated. The thermal transformations are complex processes according to TG and DTG curves including dehydration, acrylate ion oxidative degradation and thermolysis process of aromatic amine. The final products of decomposition are the most stable metal oxides.     

Thermoanalytical investigations of tris(ethylenediamine)nickel(II) oxalate and sulphate complexes

Investigations on the thermal behaviour of [Ni(en)₃]C₂O₄·2H₂O and [Ni(en)₃]SO₄ have been carried out in air and helium atmosphere. Simultaneous TG/DTA coupled online with mass spectroscopy (MS) in helium atmosphere detected the presence of H₂, O, CO, N₂/CH₂=CH₂ and CO₂ fragments during the decomposition of tris(ethylenediamine)nickel(II) oxalate and H₂, O, NH, NH₂, NH₃ and N₂/CH₂=CH₂ fragments for tris(ethylenediamine)nickel(II) sulphate complex. The thermal events during the decomposition were monitored by temperature-resolved X-ray diffraction. In air, both the complexes give nickel oxide as the final product of the decomposition. In helium atmosphere, tris(ethylenediamine)nickel(II) oxalate gives nickel as the residue, whereas tris(ethylenediamine)nickel(II) sulphate gives a mixture of nickel and nickel sulphide phases as the final residue. Kinetic analyses of these complexes by isoconversional methods are discussed and compared.     

Hydrothermal Preparation,Crystal Structure and Properties of {[ZnTCPP(EtOH)][Zn(en)]2}n(EtOH)2n with a Novel Two‐Dimensional (2‐D) Motif

A novel zinc porphyrin, {[ZnTCPP(EtOH)][Zn(en)]₂}_n(EtOH)_2n ( 1 ) (TCPP=meso‐tetra(4‐carboxyphenyl)‐porphyrin; EtOH=ethanol; en=ethylenediamine) was obtained via a hydrothermal reaction and characterized by single‐crystal X‐ray diffraction. Complex 1 crystallizes in the space group C2/c of the monoclinic system with eight formula units in a cell: a=32.465(4) Å, b=10.527(3) Å, c=31.845(3) Å, β=95.524(6) °, V=10832(4) ų, C₅₈H₅₇N₈O₁₁Zn₃, M_r=1238.23, D_c=1.518 g/cm³, S=1.005, µ(Mo Kα) =1.388 mm^?1, F(000) =5112, R=0.0650 and wR=0.1574. Complex 1 features a novel 2‐D layered motif. The spectral data of UV‐vis, FT‐IR and fluorescence are reported.     

Synthese von Tetracyanoniccolat-clathraten mit Benzol Kurze Mitteilung

Zusammenfassung Durch Ersetzung des Cadmiums im Clathrat Cden[Ni(CN)₄]·2C₆H₆ wurden drei Verbindungen des TypsM(en) _m[Ni(CN)₄]·nC₆H₆ (M ²⁺=Ni, Cu, Zn;m=2–3;n=0.14–0.28) hergestellt und charakterisiert.

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Synthesis of ethylendiamine-(metal II)-tetracyanoniccolate dibenzene clathrate compounds

Replacing cadmium ion in Cden[Ni(CN)₄]·2C₆H₆ clathrate compound three compounds ofM(en) _m[Ni(CN)₄]·nC₆H₆ type (M ²⁺=Ni, Cu, Zn;m=2–3;n=0.14–0.28) were prepared and characterized.

     

Polymorphism of the dinuclear CoIII–Schiff base complex [Co2(o‐van‐en)3]·4CH3CN (o‐van‐en is a salen‐type ligand)

Reactions of Co(OH)₂ with the Schiff base bis(2‐hydroxy‐3‐methoxybenzylidene)ethylenediamine, denoted H₂(o‐van‐en), under different conditions yielded the previously reported complex aqua[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(II), [Co(C₁₈H₁₈N₂O₄)(H₂O)], 1 , under anaerobic conditions and two polymorphs of [μ‐bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]bis{[bis(3‐methoxy‐2‐oxidobenzylidene)ethylenediamine]cobalt(III)} acetonitrile tetrasolvate, [Co₂(C₁₈H₁₈N₂O₄)₃]·4CH₃CN, i.e. monoclinic 2 and triclinic 3 , in the presence of air. Both novel polymorphs were chemically and spectroscopically characterized. Their crystal structures are built up of centrosymmetric dinuclear [Co₂(o‐van‐en)₃] complex molecules, in which each Co^III atom is coordinated by one tetradentate dianionic o‐van‐en ligand in an uncommon bent fashion. The pseudo‐octahedral coordination of the Co^III atom is completed by one phenolate O and one amidic N atom of the same arm of the bridging o‐van‐en ligand. In addition, the asymmetric units of both polymorphs contain two acetonitrile solvent molecules. The polymorphs differ in the packing orders of the dinuclear [Co₂(o‐van‐en)₃] complex molecules, i.e. alternating ABABAB in 2 and AAA in 3 . In addition, differences in the conformations, the positions of the acetonitrile solvent molecules and the pattern of intermolecular interactions were observed. Hirshfeld surface analysis permits a qualitative inspection of the differences in the intermolecular space in the two polymorphs. A knowledge‐based study employing Full Interaction Maps was used to elucidate possible reasons for the polymorphism.     

A 3d‐4f Complex Constructed by the Assembly of a Cationic Template, [Cu(en)2]2+, and a 3D Anionic Coordination Polymer, [Sm2(C2O4)3(C5O5)(H2O)2]2–

A three‐dimensional (3D) 3d‐4f complex, [Cu(en)₂][Sm₂(C₅O₅)(C₂O₄)₃(H₂O)₂] · 8H₂O ( 1 ) (en = ethylenediamine, C₅O₅^2– = dianion of 4,5‐dihydroxycyclopent‐4‐ene‐1,2,3‐trione), were prepared via the in‐situ ring‐opening oxidation reaction of croconate in the presence of the template‐directed complex, [Cu(en)₂]²⁺ cation. The structural characterization determined by X‐ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm₂(C₂O₄)₃(C₅O₅)(H₂O)₂]^2– in 1 can be describe in terms of in‐plane 2D honeycomb‐like [Sm₂(C₂O₄)₃] layered frameworks bridged by oxalate with bis‐chelating mode, being mutually interlinked via the bridge of μ_1,2,3,4‐croconate ligands with bis‐chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 × 11.893 Å (longest atom–atom contact distances) along the b axis. The structure‐directing complex, [Cu(en)₂]²⁺, and solvated water molecules are resided into these honeycomb‐type hexagonal channels. The thermal stability of 1 was further studied by TGA and in‐situ powder X‐ray diffraction measurement.     

Thermal behaviour of new biological active cadmium mixed ligands complexes

This paper reports the investigation on the thermal stability of new complexes with mixed ligands of the type [Cd(NN)(C₃H₃O₂)₂(H₂O)_m]·nH₂O [(1) NN: 1,10-phenantroline, m = 1, n = 0; (2) NN: 2,2′-bipyridine, m = 0, n = 1.5 and (C₃H₃O₂): acrylate anion]. The IR data indicate a bidentate coordination mode for both heterocyclic amine and acrylate. The in vitro qualitative and quantitative antimicrobial activity assays showed that the complexes exhibited variable antimicrobial activity against planktonic as well as biofilm embedded Gram-negative (Escherichia coli, Klebsiella sp., Proteus sp., Salmonella sp., Shigella sp., Acinetobacter boumani, Pseudomonas aeruginosa), Gram-positive (Bacillus subtilis, Staphylococcus aureus) and fungal (Candida albicans) strains, reference and isolated ones from the hospital environment. The thermal behaviour steps were investigated in synthetic air flow. The thermal transformations are complex processes according to TG and DTA curves including dehydration, amine as well as acrylate thermolysis. The final products of decomposition are the most stable metal oxides.     

Preparation, Spectral and Thermal Studies of Y(III) and Lanthanide(III) 1-Hydroxy-2-Naphthoates

Complexes of lanthanide(III) (La–Lu) and Y(III) with 1-hydroxy-2-naphthoic acid were obtained as crystalline compounds with a general formula Ln[C₁₀H₆(OH)COO]₃⋅nH₂O:n=6 for La–Tm and Y, n=2 for Yb and n=0 for Lu. IR spectra of the prepared complexes were recorded, and their thermal decomposition in air were investigated. Spectroscopic data suggest that in the coordination of metal-organic ligand only oxygen atoms from the carboxylate group take part. When heated, the complexes decompose to the oxides Ln₂O₃, CeO₂, Pr₆O₁₁ and Tb₄O₇ with intermediate formation of Ln(C₁₁H₇O₃)(C₁₁H₆O₃). This revised version was published online in August 2006 with corrections to the Cover Date.     

斯蒂芬酸氢铷的制备，晶体结构和热分解机理

A new compound,[RbHTNR]_∞[HTNR:C_6H(NO_2)_3(OH)O],was synthesized by the reaction of rubidium ni-trate and styphnic acid.The molecular structure was characterized using X-ray diffraction analysis,elementalanalysis and FTIR spectroscopy.The crystalline is monoclinic with space group P2_1/n and the empirical formulaC_6H_2N_3O_8Rb.The unit cell parameters are:a=0.4525 nm,b=1.0777 nm,c=1.9834 nm,β=90.47(2)°,V=0.96725 nm~3,Z=4,D_c=2.263 g/cm~3,Mr=329.58,F(000)=640,μ(Mo Kα)=5.165 mm~(-1).The thermal decompo-sition mechanism of the complex was studied by differential scanning calorimetry(DSC),thermogravimetry-derivative thermogravimetry(TG-DTG)and FTIR techniques.At the linear rate of 10 ℃/min,the thermaldecomposition of the complex showed three mass reducing processes between 60 and 500 ℃,and finally evolvedRbCN and some gaseous products.     

Thermal behavior of some new chromium complexes with potential biological importance

Summary This paper reports the investigation of the thermal stability of three new complexes of Cr(III) with acrylate anion, [Cr₂(C₃H₃O₂)₄(OH)₂(H₂O)₄], [Cr₃O(C₃H₃O₂)₆(C₃H₄O₂)₃](C₃H₃O₂)×5H₂O and [Cr₂(C₃H₃O₂)₅(OH)] ×2H₂O, respectively. This type of complexes is important in proper carbohydrate and lipid metabolism of mammals. The thermal decomposition steps were evidenced. The thermal transformations are complex processes according to TG and DTG curves including dehydration and oxidative degradation of acrylate ion processes. The final product of decomposition is the chromium(III) oxide.     

Synthesis and Crystal Structure of a New Oxovanadium（V） Multicomponent Complex with Acylhydrazone and Benzoylhydrazine

A new oxovanadium（V） complex with the mixed ligand of 2-oxopropionic acid benzoylhydrazone （C10H10N2O3） and benzoylhydrazine （C7H8N2O）, VO（C7H7N2O）（C10H9N2O3）, has been synthesized. Its structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to monoclinic system with space group P21/n and cell parameters： a=1.1136（4） nm, b=0.6217（2） nm, c=2.6038（9） nm, β=97.182（6）°, V= 1.7887（11） nm^3, Z=4, F（000）=836, Mr=407.28, Dc= 1.512 g/cm^3,μ （Mo Kα） =0.592 mm^-1, R1 =0.0445, wR2= 0.1203. Vanadium atom is 6-coordinated by carboxyl and carbonyl O atoms and N atom of one tridentate C10H10N2O3 to form two stable five-membered rings with the same edge, and the other coordinated atoms of N and O come from one bidentate benzoylhydrazine C7H8N2O. The title complex has a six-coordinated V center [VO（N2O3）] with a distorted octahedral arrangement. In the crystal lattice, there are hydrogen bonding interactions between two molecules.     

Mechanochemical Synthesis and Characterization of Alkaline Earth Metal Terephthalates: M(C8H4O4)·nH2O (M = Ca,Sr, Ba)

The mechanochemical synthesis offers an easy access to obtain alkaline earth metal terephthalates M(C₈H₄O₄) · nH₂O (M = Ca, Sr, Ba). In the presented study we describe for the first time the mechanochemical synthesis of powders of Ca(C₈H₄O₄) · 3H₂O, Ca(C₈H₄O₄), Sr(C₈H₄O₄) · H₂O, and Ba(C₈H₄O₄), which so far were only synthesized as single crystals from aqueous solutions or by reactions in an autoclave. Furthermore, a new hydrate Ba(C₈H₄O₄) · 2(1.5)H₂O, not described so far in the literature, was prepared. All compounds were characterized by X‐ray powder diffraction, thermal analysis, elemental analysis, FT‐IR, and MAS NMR spectroscopic measurements.     

Synthesis and characterization of solid molybdenum(VI) complexes with glycolic,mandelic and tartaric acids. Photochemistry behaviour of the glycolate molybdenum complex

The complexes (NH₄)₂[MoO₂(C₂H₂O₃)₂]·H₂O, (NH₄)₂[MoO₂(C₈H₆O₃)₂] and (NH₄)₂[MoO₃(C₄H₄O₆)]·H₂O were prepared by reaction of MoO₃ with glycolic, mandelic and tartaric acids, respectively. The complexes were characterized by elemental and thermal analysis, IR spectroscopy and X-ray diffraction. Crystals of the glycolate and tartarate complexes are orthorhombic and the mandelate complex is monoclinic. Elemental and thermal analysis data showed that the glycolate and tartarate complexes are monohydrated. Hydration water is not present in the structure of the mandelate complex. IR spectra showed COO^? is involved in coordination as well as the oxygen atom of the deprotonated hydroxyl group of the α-carbon. The glycolate molybdenum complexes with general formula M₂[MoO₂(C₂H₂O₃)₂]·nH₂O, where M is an alkali metal and n?=?1 or ½, were also prepared and characterized. Aqueous solutions of the glycolate complex become blue and mandelate and tartarate complexes change to yellow or brown when exposed to UV-radiation.     

Kinetic and thermodynamic parameters of the thermal decomposition of zinc(ii) dialkyldithiocarbamate complexes

The thermodynamic and kinetic parameters of the thermal decomposition of Zn(S₂CNR₂)₂ complexes (R=CH₃, C₂H₅ and n-C₃H₇) were determined with the dynamic thermogravimetric method. Superimposed TG/DTG/DSC curves show that thermal decomposition reactions for chelates with R=C₂H₅ and n-C₃H₇ occur in the liquid phase, at temperatures far away from their melting points, whereas for the complex with R=CH₃ the thermal decomposition begins at a temperature closer to its melting point, suggesting a rather complex decomposition mechanism. This revised version was published online in August 2006 with corrections to the Cover Date.     

A Novel Self‐assembled Supramolecular Complex {[Cu(n) (en)2·H2O] [Cu(I)2(CN)4]}n with Honeycomb‐like Structure and Its Adsorption Properties

A novel supramolecular complex {[Cu(n)(en)₂·H₂O]·[Cu(I)₂(CN)₄]}_n (en = ethylenediamine), in which the cyanide‐bridged Cu(I) forms the honeycomb‐like skeleton host and the Cu(n) complex ion [Cu(en)₂·H₂O]²⁺ is encapsulated in the center of the channel cavity of the skeleton, was synthesized by two different methods. The complex was also characterized by elemental analysis, ICP analysis, IR spectra and thermal analysis. The adsorption and desorption studies of the complex indicate that H₂O and NH₃ can be desorbed and re‐adsorbed without collapse of the channel structure of the supramolecule.     

Preparation,Characterization and Solid State Thermal Studies of Cadmium(II) Squarate Complexes ofhane-1,2-diamine and its Derivatives

[CdL₃]C₄O₄ [L=ethane-1,2-diamine (en)], [CdL₂(H₂O)₂]C₄O₄ [L=N-methylethane-1,2-diamine (meen), N-ethylethane-1,2-diamine (eten), N-propylethane-1,2-diamine (pren), propane-1,2-diamine (pn) and N-methylpropane-1,2-diamine (ibn)] and [CdL₂(C₄O₄)] [L=N-isopropylethane-1,2-diamine (ipren)] have been synthesized by the addition of the respective diamine to finely powdered CdC₄O₄×₂H₂O and their thermal studies have been carried out in the solid state. [Cd(en)₃]C₄O₄ upon heating loses two molecules of diamine in two overlapping steps yielding Cd(en)C₄O₄ which upon further heating transforms to unidentified products. The diaquabis(diamine) species, [CdL₂(H₂O)₂]C₄O₄, show thermally induced deaquation-anation reaction in the solid state and thereby produce [CdL₂(C₄O₄)], which reverts on exposure to humid atmosphere (RH =90%) for 20–24 h. All the squarato bis(diamine) species, [CdL₂(C₄O₄)], on pyrolysis in the solid state transform to unidentified products through the formation of intermediates, CdL_1.5C₄O₄, (L=meen, pren and ipren), CdLC₄O₄ (L=meen, en, pren, ipren, pn and ibn) and CdL_0.5C₄O₄ (L=eten, pn and ibn). However, amongst the intermediates only the mono diamine species, CdLC₄O₄ can be isolated in pure form and the pyrolytic process is the only way to synthesize them. The monodiamine species can be stored in a desiccator as well as in an open atmosphere and proposed to have a polymeric structure. This revised version was published online in August 2006 with corrections to the Cover Date.     

Thermal behaviour of hydrated lanthanide complexes with heptanedioic acid

The multi-step dehydration and decomposition of trivalent lanthanum and lanthanide heptanediate polyhydrates were investigated by means of thermal analysis completed with infrared study. Further more, X-ray diffraction data for investigated heptanediate complexes of general stoichiometry Ln₂(C₇H₁₀O₄)₃.nH₂O (wheren=16 in the case of La, Ce, Pr, Nd and Sm pimelates,n=8 for Eu, Gd, Tb, Dy, Er and Tm pimelates,n=12 for Ho, Yb and Lu pimelates) were also reported.

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Zusammenfassung Mittels TG, DTG, DTA wurde in Verbindung mit IR-Methoden der mehrstufige Dehydratations- und der Zersetzungsvorgang der Polyhydrate der PimelinsÄuresalze von dreiwertigem Lanthan und dreiwertigen Lanthanoiden untersucht. Röntgendiffraktionsdaten der untersuchten Heptandiat-Komplexe mit der allgemeinen Formel Ln₂(C₇H₁₀O₄)₃ nH₂O (mitn=16 für Ln=La, Ce, Pr, Nd und Sm,n=8 für Ln=Eu, Gd, Tb, Dy, Er und Tm sowien=12 für Ln=Ho, Yb und Lu) werden ebenfalls gegeben.