Complex In Different Solvents Research Articles

Review of Solvation Studies of Copper (1) Complexes in Different Solvents and at Different Temperatures

The study of the solvation behavior of copper (1) complexes in the mixed solvents has generated a great interest in the field of chemistry. Copper complexes have attracted wide attention due to their important role in analytical chemistry, organic synthesis, metallurgy and medicines etc. Nevertheless, during recent years there has been an increasing interest in the behavior of copper (1) complexes in aqueous and non-aqueous solvents with a view to investigate ion-ion and ion solvent or solute solute interactions under varied conditions. The solvation behavior of some copper(I) perchlorate complexes in binary mixtures of dimethylsulfoxide with dimethylacetamide and dimethylformamide at 298k, and Some Copper(I) Nitrate Complexes in Dimethylsulfoxide and Nitromethane at 298 K and copper sulfate have been measured in binary mixtures of aqueous–methanol mixtures at different temperatures is studied by a combined approach using Molar conductance, ultrasonic velocity and density data, or limiting molar conductance (Λ0), the association constants (KA) respectively . This study is a condensed version of earlier work in the same fields. Keywords: solvation, Molar conductance, Copper sulfate, copper(I) perchlorate

Solvatochromic, Halochromic and Thermochromic Effects of Copper(II) Complexes Containing N-tert-butyl 2-Picolylamine, and Halide Ion; a Computational Study

The dihalido N-tert-butyl 2-picolylamine copper(II) complexes, [CuLX2], where X= Cl, Br were synthesized and characterized by elemental analysis, UV–Vis, FT-IR, and EPR spectra, and molar conductance measurements as well as TG and DTA. The crystal structures of the complexes were identified by single-crystal X-ray diffraction analysis, and the density functional theory (DFT) level calculations that reveal both complexes adopt distorted square-planar geometries. The complexes are thermochromic, solvatochromic, and halochromic. The chromotropism properties were investigated using visible electronic absorption spectroscopy. Their solvatochromism properties were investigated in solvents with different polarities and it was found that the observed solvatochromism originates from structural changes of the complexes in different solvents. The aqueous solutions of the complexes exhibit color changes in the pH range of 2.68 to 9.84due to protonation ad deprotonation of ligand. The compounds are also thermochromic and show reversible color changes in different temperatures in high boiling point solvents. Both compounds showed the same identity in an aqueous solution due to the substitution of the water molecules with the halide ligands. These spectroscopic changes were supported by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations.

GC-MS PROFILE, SYNTHESIS AND SPECTRAL CHARACTERIZATION OF FLAVONOID-METAL (CADMIUM, COBALT, COPPER, NICKEL) COMPLEXES OF JATROPHA CURCUS LEAVES

Objective: The main aim of this research is to determine the optimum conditions required for the synthesis of metal-flavonoid complexes from leaves of Jatropha curcus. Methods: Soxhlet extractor was used for the extraction. Phytochemical screening was carried out using the method described by Harborne. The phytochemical profile of the extract was determined using GC-MS. The flavonoid-metal complexes were synthesized using different transition metal salts and the methanolic plant leaves extract. The synthesis was carried out by varying the pH, metal ion and extract concentrations. The solubility of the flavonoid-metal complexes in different solvents was determined. The synthesized complexes were subjected to UV-visible and FTIR analysis. Results: Methanol extract gave a yield of 4. 88%. Phytochemical screening revealed the presence of Flavonoids, steroids and alkaloids. The GC-MS analysis showed the presence of 14 compounds. Maximum dry weights of complexes formed between 600-700 mg were obtained at a concentration of 1000 ppm crude extract and for the metal ion concentrations, the optimum concentration observed for Cd2+and Cu2+complexes was 120 ppm while that of Ni2+and Co2+complexes was 140 ppm. Most suitable pH for copper-flavonoid was 8, for cobalt-and cadmium-flavonoid complexes was 9 and pH of 10 for nickel-flavonoid complexes. The FTIR results showed the formation of the complex due to the shift observed in the band assigned to C=O The UV/visible spectrum showed absorbance in the wavelength range of 250-480 nm. Conclusion: Flavonoid-metal complexes were synthesized and their optimum conditions determine.

Photoswitchable Copper(I) and Copper(II) Complexes of Phenylazo‐3,5‐dimethylpyrazole Incorporated Ligands

AbstractWe report the design, synthesis, characterization, and photochemistry of three photoresponsive azoheteroarene‐based neutral N‐donor ligands. Furthermore, those bidentate and tridentate ligands have been coordinated with Cu(I) and Cu(II) metal ions to form seven complexes exhibiting different geometries and nuclearities. Detailed studies of the electronic properties, photoswitching, and thermal reverse isomerization behavior of the photoswitched states of the free ligands and their metal complexes in different solvents are presented.

Synthesis, crystal structure, and chromotropism properties of Dihalo N-2-ethanolpicolylamine copper(II)

Two copper (II) mononuclear complexes with the general formula [Cu(HL)X2], which L = N-2-ethanolpicolylamine and X = Cl, Br, were synthesized and characterized by elemental analysis infrared, electronic absorption spectroscopy techniques, and conductivity method. The distorted square pyramidal geometry of [Cu(HL)Cl2] was confirmed by the density functional theory level (DFT) calculation and X-ray crystallography. The complexes are soluble in polar solvents and are chromotropic. It was found both complexes have a similar identity in aqueous solution due to dissociation of halides and hydration. Their chromotropism behavior, including solvato-, thermos- and halochromism, was investigated using visible absorption spectroscopy. The original green complex displayed a reversible color change to blue in alkaline and almost colorless in acidic solutions. The pH effect on the visible absorption spectrum of the complex was studied that functions as pH-induced “off–on-off” switches triggered by the deprotonation of ligand in an alkaline aqueous solution and protonation along with loss of the ligand HL in an acidic medium. The complex also exhibited thermochromism and solvatochromism due to solvation and structural change. Further computational analysis of the electronic structure of the complex in different solvents was executed to gain a deeper insight into the properties associated with molecular orbitals. Its electronic spectrum was analyzed, and bands were assigned through the time-dependent density functional theory level (TDDFT) calculation, together with DFT-based molecular modeling

Solvent effects on the interaction between alkali metal cations and 1,3-Diisopropoxycalix [4] arenecrown-6: Nuclear magnetic resonance spectroscopy and Independent Gradient Model Non-Covalent interactions analysis

The combination of 1,3-Diisopropoxycalix [4] arenecrown-6 (BPC6) and alkali metal ions were studied in different solvents by 1H and 133Cs Nuclear magnetic resonance (NMR) spectra, gmx_MMPBSA, and Independent Gradient Model (IGM) non-covalent interactions analysis based on Molecular Dynamics (MD) Simulations. The binding energy of BPC6·M+ complex follows the order: BPC6·Cs+ > BPC6·Rb+ > BPC6·K+ in CHCl3, which is completely reverse to that in vacuum. In addition, the coordination properties depend on solvent polarity: In the low polarity solvent such as CHCl3, all the oxygens in crown ether chain of BPC6 are involved in the coordination with Cs+ ions. By comparison, in the high polarity solvents such as CH3CN and CH3OH, the number of oxygens participates in the complexation decreases, and the cation-π interaction areas of complexes are also reduced. That is because the contribution of electrostatic interactions in complexation is weakened by solvent effect. The cation-π interaction plays a very important role in selectivity among alkali metal cations and coordination stability of BPC6·M+ complex in different solvents.

Antimicrobial activities of two 1‐D, 2‐D, and 3‐D mononuclear Mn (II) and dinuclear Bi (III) complexes: X‐ray structures, spectroscopic, electrostatic potential, Hirshfeld surface analysis, and time‐dependent/density functional theory studies

AbstractTwo mononuclear and dinuclear octahedral complexes, [Mn(L1)2Cl2] (1) and [Bi2(L2)2Cl8] (2) (L1 = 2‐(2‐pyridyl)‐4‐methyl‐1,2‐dihydroquinazoline‐N3‐oxide, L2 = 2‐(3‐pyridyl)‐4‐methyl‐1,2‐dihydroquinazoline‐N3‐oxide) were prepared by natural volatilization method. The ligands and both complexes were compared with spectroscopic methods, as well as characterized by elemental analysis. The photoluminescence behaviors of both complexes in different solvents were also investigated. The coordination possibility of ligands toward Mn (II)/Bi (III) was verified using X‐ray crystallography, and it revealed that the ratio of ligand to metal was 2:1 in 1, whereas 1:1 in 2. The adjacent molecules of six‐coordinated complex 1 constituted an infinite 1‐D chain, 2‐D network, and ladder‐like 3‐D supramolecular frameworks. Most strikingly, hexa‐coordinated complex 2 with dinuclear structure formed an infinite 1‐D chain, 2‐D layered and meter‐shaped 3‐D supramolecular skeleton. Density functional theory (DFT) calculation was used to optimize the geometry of complexes, compute the electrostatic potential diagrams, and evaluate the HOMO‐LUMO energy gap. The electronic transition simulated through time‐dependent (TD)‐DFT level of calculation rationalized the experimental data. The antibacterial properties of all compounds were evaluated against Gram‐positive and Gram‐negative bacterial strains. In addition, the Hirshfeld surface was utilized to quantify some hydrogen bonding interactions and their contributions.

Neutron Scattering Techniques for Studying Metal Complexes in Aqueous Solution.

Neutron scattering combined with ab initio calculations provides a powerful tool for studying metal complexes in different solvents and, particularly, in water. The majority of traditional characterization techniques in catalysis provide only limited information on homogeneous catalytic processes. Neutron scattering, on the other hand, thanks to its sensitivity to hydrogen atoms, and therefore water molecules, can be used to build detailed models of reaction paths and to observe, at a molecular level, the influence of solvent molecules on a catalytic process. In this Mini-Review we describe several examples on how neutron scattering combined with ab initio calculations can be used to examine the nature of the interaction of water molecules with catalytically active metal complexes in solution.

Synthesis, structures, and DFT analysis of gold complexes containing a thiosemicarbazone ligand

A mixture of E,Z-thiosemicarbazone (TSC) allows the formation of two Au(i) complexes; the reaction of TSC with KAuCl4 yields two complexes in different solvents.

Theoretical investigation on the non-covalent interactions of acetaminophen complex in different solvents: study of the enhancing effect of the cation–π interaction on the intramolecular hydrogen bond

In the current research, a comprehensive study is performed on the non-covalent interactions of the acetaminophen complex in the presence of various solvents. In addition, the effect of cation–π interaction on the strength and nature of the intramolecular hydrogen bond (H-bond) is explored by density functional theory method. The computations are performed using the M06-2X functional and the 6-311++G(d,p) basis set. The obtained results reveal that both interactions become stronger in the gas phase with respect to the solution phase. The “atoms in molecules” theory and the natural bond orbital method are also applied to get more details about the investigated interactions character. Based on the achieved outcomes, the H-bond of the studied complex is placed in the weak H-bond category. Our findings indicate that the intramolecular H-bond is strengthened by the cation–π interaction in the different solvents. Finally, the physical properties such as frontier molecular orbitals, energy gap, dipole moment, chemical hardness as well as electronic chemical potential are investigated to evaluate the electronic properties, stability and reactivity of the studied complex.

The determination of molecular dynamic properties of Novel 5-oxo-1,2,4-triazole phthalocyanines and investigation of their urease inhibition properties

In present study, the novel peripherally [3-methyl-5-oxo-4-(4-phenoxyphenyl)-4,5-dihydro-1H-1,2,4-triazol-1-yl] substituted Zn(II), Cu(II), Co(II) phthalocyanines were synthesized and characterized spectroscopically. The light absorption/emission behavior of the synthesized phthalocyanines were determined by UV-Vis and fluorescence spectroscopy. The fluorescence quantum yields of the novel phthalocyanine Zn(II) complex in different solvents were calculated. Besides, the urease inhibition activities of the novel compounds were investigated. All synthesized phthalocyanines have a superior inhibitory activity on urease enzyme, while novel phthalocyanines Cu(II) showed the best inhibitory effect against jack bean urease with IC50 values of 0.0035 ±0.0010 µM.

Spectroscopic and TDDFT studies on the charge-transfer properties of metallated Octa(carbazolyl)phthalocyanines

Four novel phthalocyanine complexes containing carbazole moieties were synthesized and characterized by 1H &13C NMR, IR, and UV–visible spectroscopies, magnetic circular dichroism (MCD), elemental analysis, matrix-assisted laser desorption ionization mass spectrometry (MALDI), and X-ray crystallography. In all new compounds, characteristic interligand charge transfer transitions were observed in the 400–600 nm range and are indicative of interligand charge transfer transitions. The electrochemical and spectroelectrochemical methods used to probe the redox properties of 2–5 suggested phthalocyanine-centered first oxidation and reduction processes. Photophysical measurements of the prepared complexes in different solvents exhibited interesting properties due to the charge transfer effect and consequently prolonged excited state lifetime (5.00 ns) with high singlet oxygen quantum yield (ФΔ = 0.825) were acquired. Due to their remarkable solvatochromism phenomena and enhanced photo-related properties, the presented compounds have high potential in chemo-sensors and optical limiting material applications.

Reevaluating the effects of reorganization energy on electron transfer rate for quantum dot-molecular acceptor complexes in different solvents.

The electron transfer (ET) rate in quantum dot (QD)-molecular acceptor systems is dependent upon system reorganization energy (RE, λ), which comprises contributions from solvent (λ0) and reactants (λi). However, to date, the effect of λi on ET rate has been largely ignored. Herein, the ET from CdSe/ZnS QDs to 1-chloroanthraquinone (1-CAQ) in different solvents was investigated using ultrafast transient absorption spectroscopy as a means to evaluate the effect of λi on ET rate. The results revealed that ET rate is strongly solvent dependent. Amazingly, the ET rate in carbon disulfide is 300-times higher than that in n-dodecane. Theoretical calculations indicated that the λi contribution from 1-CAQ alone accounts for a large proportion of system RE and varies greatly in different solvents. Furthermore, the ET rate increases first and, then, decreases with the λ value in different solvents. This trend was interpreted consistently in terms of Marcus theory by adding λi to λ for different solvents. Thus, our present work demonstrates that the RE of the acceptor molecule has a non-negligible effect on ET rate, providing new insight into the mechanisms of ET process and for the development of QD-based devices.

Synthesis, spectroscopic, thermal, fluorescence properties and molecular modeling of novel Pt(II) complex with schiff base containing NS donor atoms

New transition metal complex of Pt(II) of the Schiff base ligand with (E)-2-((1-(thiophen-2-yl)ethylidene)amino)phenol HL have been synthesized using the ultrasonic irradiation and characterized by physicochemical and spectroscopic methods. The IR spectrum of Pt(II) complex showed that the coordination in metal ions via the imine N and S atoms. Magnetic and UV–Vis spectra showed that the geometrical structure of Pt(II) complex is square planar. The molar conductance data revealed that Pt(II) complex is non-electrolyte. The thermodynamic parameters for thermal decomposition of Pt(II) complex was calculated from analysis of the TG-DTG curves using Hörowitz–Metzger method. The fluorescence of the ligand HL and its Pt(II) complex in different solvents and pH conditions have also been studied in detail. The quenching of the fluorescence intensity of the ligand can be noted obviously, in the presence of Pt(II) ion. Geometry optimization of the compounds was calculated by semiempirical molecular orbital theory PM3 method using Hyperchem 7.52 program.

Kinetic study of the Catecholase activities of a tetranuclearCu(I) complex in different Solvents

Kinetic study of the Catecholase activities of a tetranuclearCu(I) complex in different Solvents

Ultrafast Charge Recombination Dynamics in Ternary Electron Donor-Acceptor Complexes: (Benzene)2-Tetracyanoethylene Complexes.

The charge-transfer (CT) state relaxation dynamics of the binary (1:1) and ternary (2:1) benzene/tetracyanoethylene (BZ/TCNE) complexes are reported. Steady-state and ultrafast time-resolved broadband fluorescence (TRFL) spectra of TCNE dissolved in a series of BZ/CCl4 mixed solvents are measured to elucidate the spectroscopic properties of the BZ/TCNE complexes and their CT-state relaxation dynamics. Both steady-state and TRFL spectra exhibit marked BZ concentration dependences, which can be attributed to the formation of two types of 2:1 complexes in the ground and excited states. By combining with the density functional theory (DFT) calculations, it was concluded that the BZ concentration dependence of the absorption spectra is mainly due to the formation and excitation of the sandwich-type 2:1 ternary complexes, whereas the changes in fluorescence spectra at high BZ concentrations are due to the formation of the asymmetric-type 2:1 ternary complex CT1 state. A unified mechanism involving both direct excitation and secondary formation of the 2:1 complexes CT states are proposed to account for the observations. The equilibrium charge recombination (CR) time constant of the 1:1 CT1 state is determined to be ∼150 ps in CCl4, whereas that of the 2:1 DDA-type CT1 state becomes ∼70 ps in 10% BZ/CCl4 and ∼34 ps in pure BZ. The CR rates and the CT1-S0 energy gap of these complexes in different solvents exhibit a correlation conforming to the Marcus inverted region. It is concluded that partial charge resonance occurring between the two adjacent BZs in the asymmetric-type 2:1 CT1-state reduces the CR reaction exothermicity and increases the CR rate.

Electron Paramagnetic Resonance and DFT Analysis of the Effects of Bulky Perfluoroalkyl Substituents on a Vanadyl Perfluoro Phthalocyanine

Abstract F64PcVO, the vanadyl complex of the perfluoro-isopropyl-substituted perfluorophthalocyanine ligand F64PcH2, exhibits interesting electronic properties compared to related vanadyl phthalocyanine complexes. X- and W-band continuous-wave electron paramagnetic resonance (CW EPR) of undiluted F64PcVO powders illustrate the absence of π-π stacking in these materials due to the bulky substituents. Furthermore, pulsed EPR and electron nuclear double resonance (ENDOR) experiments in combination with density functional theory (DFT) computations were used to determine the principal g values and the 51V, 14N, 1H and 19F hyperfine couplings of a frozen ethanol solution of F64PcVO. The axial ligation of ethanol to vanadium was proven. Axial accessibility of the vanadyl center combined with the high solubility of the complex in different solvents make F64PcVO an interesting molecule for catalytic applications.

Computational investigation of solvent effect on the structure, spectroscopic properties (13C, 1H NMR and IR, UV), NLO properties and HOMO–LUMO analysis of Ru(NHC)2Cl2(=CH-p-C6H5) complex

ABSTRACTThis paper presents, a theoretical study of the structural, 13C and 1H NMR chemical shifts, electronic transitions, vibrational analysis, and first hyperpolarizability for Ru(NHC)2Cl2(=CH-p-C6H5) complex in gas phase and different solvents. The solvent effect on structural parameters, frontier orbital energies, Ru=Ccarbene and Ccarbene-H stretching frequencies, and chemical shifts of Ccarbene, CNHC and Hcarbene of complex was explored based on Polarizable Continuum Model (PCM). The wavenumbers of υ(Ru=Ccarbene) and υ(Ccarbene-H) of complex in different solvents were correlated with the Kirkwood–Bauer–Magat equation (KBM). As well as, the polarizability and the first order hyperpolarizability values of the investigated compound were computed in various solvents.

Synthesis and Molecular Structures of Some New Cu(II) and Fe(III) Diclofenac Drug Complexes in Different Solvents

Synthesis and Molecular Structures of Some New Cu(II) and Fe(III) Diclofenac Drug Complexes in Different Solvents

Synthesis, structure and stability of a chiral imine-based Schiff-based ligand derived from L-glutamic acid and its [Cu4] complex

Studies of the stability of a ligand derived from L-glutamic acid and ortho-vanillin and its new [Cu4] complex are presented. The [Cu4] complex contains a heterocubane [CuII4O4] core and pendant carboxylic groups increasing its solubility in water, also under basic conditions. The stability of the complex in different solvents is confirmed with ESI-MS studies and such experiments as successful recrystallization. The complex is stable also under physiological conditions whereas the ligand is partly decomposed to L-glutamic acid and ortho-vanillin.