Dimethyl Sulfoxide Complexes Research Articles

Диметилсульфоксидные комплексы осмия. Кристаллическая структура комплекса [H(DMSO)2][OsIIIBr4(DMSO)2

Диметилсульфоксидные комплексы осмия. Кристаллическая структура комплекса [H(DMSO)2][OsIIIBr4(DMSO)2

Synthesis, spectroscopic evaluation, molecular modelling, thermal study and biological evaluation of manganese(II) complexes derived from bidentate N,O and N,S donor Schiff base ligands

Manganese(II) complexes having the general composition Mn(L)2X2 (where L = 3‐bromoacetophenone semicarbazone, 3‐bromoacetophenone thiosemicarbazone, 1‐tetralone semicarbazone, 1‐tetralone thiosemicarbazone, flavanone semicarbazone or flavanone thiosemicarbazone and X = Cl− or ½SO42−) were synthesized. All the complexes were characterized using elemental analyses, molar conductance and magnetic moment measurements, and mass, 1H NMR, infrared, electron paramagnetic resonance and electronic spectral studies. The molar conductance of the complexes in dimethylsulfoxide lies in the range 10–20 Ω−1 cm2 mol−1 indicating their non‐electrolytic nature. All the complexes show magnetic moments corresponding to five unpaired electrons. The possible geometries of the complexes were assigned on the basis of electron paramagnetic resonance, electronic and infrared spectral studies. Some of the synthesized ligands and their complexes were screened for their antifungal activities against fungi Macrophomina phaseolina, Botrytis cinerea and Phoma glomerata using the food poison technique and their antibacterial activities against Xanthomonas campestris pv. campestris and Ralstonia solanacearum using the paper disc diffusion method. They showed appreciable activities.

Self-Assembly with 2,6-Bis(1-(pyridin-4-ylmethyl)-1H-1,2,3-triazol-4-yl)pyridine: Silver(I) and Iron(II) Complexes.

A new “click” ligand, 2,6-bis(1-(pyridin-4-ylmethyl)-1H-1,2,3-triazol-4-yl)pyridine (L) featuring a tridentate 2,6-bis(1,2,3-triazol-4-yl)pyridine (tripy) pocket and two pyridyl (py) units was synthesized in modest yield (42%) using the copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The coordination chemistry of the ligand with silver(I) and iron(II) ions was examined using a battery of solution (1H and DOSY (diffusion ordered spectroscopy) nuclear magnetic resonance (NMR), infrared and absorption spectroscopies, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS)), and solid state (X-ray crystallography, elemental analysis) techniques. When treated with silver(I) ions, the ligand forms discrete [Ag(L)]+ (X−, where X− = BF4−, NO3− or SbF6−) complexes in dimethyl sulfoxide (DMSO) solution but these complexes crystallize as coordination polymers. The addition of [Fe(H2O)6](BF4)2 to an acetonitrile solution of the ligand forms the expected monomeric octahedral [Fe(L)2]2+ complex and treatment of the iron(II) complex with AgBF4 generates a heterometallic linear coordination polymer.

Conformational and structural diversity of iridium dimethyl sulfoxide complexes

Transition metal complexes containing dimethyl sulfoxide (DMSO) are important precursors in catalysis and metallodrugs. Understanding the solid-state supramolecular structure is crucial for predicting the properties and biological activity of the material. Several crystalline phases of DMSO-coordinated iridium anions with different cations, potassium (1a) and n-butylammonium (1b), were obtained and their structures determined by X-ray crystallography. Compound (1a) is present in two solvatomorphic forms: α and β; the β form contains disordered solvent water. In addition, the structures exhibit different rotamers of the trans-[IrCl4(DMSO)2]− anion with the trans-DMSO ligands being oriented in anti and gauche conformations. In consideration of these various conformers, the effects of the crystallized solvent and intermolecular interactions on the conformational preferences of the anion are discussed. In addition, density functional theory calculations were used to investigate the energies of the anions in the different conformations. It was found that hydrogen bonds between water and the DMSO complex stabilize the gauche conformation which is the least stable form of the trans-DMSO complex. Consequently, by controlling the number of hydrogen-bond donors and acceptors and the amount of water, it may be possible to obtain different solvatomorphs of clinically significant metallodrugs.

Luminescent PtII Complexes of Tridentate Cyclometalating 2,5‐Bis(aryl)‐pyridine Ligands

Bis‐cyclometalated PtII complexes of dianionic 2,5‐bis(aryl)‐pyridine ligands (L1–6)2–, carrying various cyclometalating or pending aryl groups, are synthesised in two steps. The reactions of H2L protoligands with K2[PtCl4] in acetic acid give the mono‐cyclometalated complexes [Pt(HL)Cl]2. Heating these complexes in hot DMSO (dimethyl sulfoxide) yields the double‐cyclometalated DMSO complexes [Pt(L1–6)(DMSO)]. The reaction of [Pt(L4)(DMSO)] with N,N‐dimethylimidazolium iodide in the presence of KOtBu as the base gives the carbene complex [Pt(L4)(Me2Imd)]. Detailed photophysical studies reveal the intense orange luminescence of these complexes in CH2Cl2 solution, with quantum yields up to 0.22, and increased quantum yields of up to 1.00 in glassy frozen CH2Cl2/MeOH (1:1) and up to 0.44 in PMMA matrices. Detailed electrochemistry (including spectroelectrochemistry) reveals reversible ligand‐based first reductions at –2.1 to –2.3 V, irreversible Pt‐centred oxidations at around 0.8 V and electrochemical band gaps of 2.8–3.0 eV. Further reduction waves at very negative potentials interfere with the solvent (THF with traces of water) discharge and can be traced, with UV/Vis spectroelectrochemistry, to Pt‐centred reductions for the DMSO complexes and to a second ligand‐centred reduction for the Me2Imd complex from. The photo/electrochemical properties can be roughly correlated with the ligand pattern and suggest their use in optoelectronic applications.

On the structure of monohalomercury(II) complexes in dimethylsulfoxide, pyridine and N,N-dimetylthioformamide solution

The structures of the monohalomercury(II) complexes, [HgX]+, in dimethylsulfoxide (dmso), pyridine and N,N-dimethylthioformamide (dmtf) solution have been studied by means of EXAFS. All complexes in the Hg2+-X− systems, X = Cl, Br and I, in dmso and pyridine have the unique property with wide range of predominance of all individual complexes. This means that all complexes can be individually characterized in solution. The previously reported complex formation thermodynamics in dmso and pyridine predicted a substantial desolvation at the formation of the first complex. This study shows that the dmso and pyridine solvated [HgX]+ complexes have one solvent molecule strongly bound “trans” to the halide ion and another two weakly bound solvent molecules in the remaining positions of linearly distorted tetrahedra. This shows that a substantial desolvation of the hexasolvated mercury(II) ions takes place at the formation of the [HgX]+ complexes. The strongly bound dmso molecule binds through its oxygen atom to mercury(II) in the [HgCl]+ and [HgBr]+ complexes, while in the [HgI]+ complex through its sulfur atom. The Hg–X bonds are slightly shorter in the [HgX]+ complexes than in corresponding [HgX2] complexes, and the short Hg–O and Hg–N bond distances are ca. 0.35 and 0.25 Å shorter than in the octahedral hexakis(dmso)- and -(pyridine)mercury(II) solvates, respectively. In dmtf solution, the dmtf solvated mercury(II) ion is four-coordinate in tetrahedral fashion. The structures of the dmtf solvated [HgX]+ complexes show the same basic tetrahedral configuration as the mercury(II) solvate. This shows that a simple substitution reaction takes place at the formation of the [HgX]+ complexes in dmtf.

Dimethyl Sulfoxide Complexes Detected at Ambient Conditions.

Dimethyl sulfoxide (DMSO) is an important intermediate in the atmospheric oxidation of dimethyl sulfide (DMS). DMS, emitted from the ocean, is the main natural sulfur source, and its oxidation products are essential in the formation of sulfate aerosols. The high atmospheric concentration of water makes hydrogen bonding with DMS and its oxidation products likely. Through hydrogen bonding, water can potentially catalyze and affect the steps of the oxidation. We investigate binary hydrogen-bound complexes involving DMSO. Both water·DMSO and methanol·DMSO complexes are identified in an Ar matrix, and at room temperature, a Gibbs free energy of 0.7 kJ/mol for the formation of the methanol·DMSO complex is determined. Assuming a similar Gibbs free energy of the hydrate, it would suggest a relatively high abundance of the DMSO hydrate relative to the monomer in the atmosphere. The effect of changing the atom divalently bound to the hydrogen bond accepting oxygen, from S to C (DMSO to acetone), is found to significantly decrease the equilibrium constant of complex formation.

Room-Temperature Synthesis of Widely Tunable Formamidinium Lead Halide Perovskite Nanocrystals

Colloidal perovskite nanocrystals based on formamidinium lead halide (FAPbX3) have been synthesized by the ligand-assisted reprecipitation method using PbX2–dimethyl sulfoxide complexes as precursors at room temperature. Well-defined cubic-shaped FAPbX3 nanocrystals have been obtained with a size d of ∼10 nm. The synthesized FAPbX3 nanocrystals show bright photoluminescence with a high photoluminescence quantum yield (75% for FAPbBr3). The lifetimes of FAPbBr3 nanocrystals were measured for the samples isolated at several different centrifugal speeds. The photoluminescence can be tuned from the blue to near-infrared region (λpeak = 408–784 nm) by changing either the amount of oleylamine or the composition of X. The color expression range is 135% of the NTSC standard. The bandwidth of the photoluminescence spectra of FAPbX3 nanocrystals is narrow (full width at half-maximum of 18–48 nm). FAPbX3 nanocrystals show thermal stability that is better than that of MAPbBr3 nanocrystals.

Electrochemical and chemical syntheses, structures, and optical properties of the zinc and cadmium complexes in the N,N,O,S-ligand environment

The chemical and electrochemical syntheses of the zinc (I) and cadmium (II) complexes are carried out on the basis of the tridentate Schiff base (H2L), the condensation product of (2-tosylaminoaniline) N-(2-aminophenyl)-4-methylbenzenesulfunamide with 1-phenyl-3-methyl-4-formylpyrazole-5-thiol. The structures and compositions of the synthesized metallochelates are proved by the data of C, H, and N elemental analyses, IR spectroscopy, and 1H NMR spectroscopy. X-ray absorption spectroscopy is used to determine the structure of the zinc complex. The binuclear structure of the cadmium complex is confirmed by the X-ray diffraction data (CIF file CCDC no. 1471159). The optical properties of H2L and the zinc and cadmium complexes in dimethyl sulfoxide (DMSO) solutions are studied.

High Performance of Perovskite Solar Cells via Catalytic Treatment in Two-Step Process: The Case of Solvent Engineering.

Currently, the potential mechanism of the solvent-assisted crystallization for mixed cations perovskite thin film (FAxMA1-xPbI3) prepared via two-step solution-process still remains obscure. Here, we clarified the molecular-competing-reacted process of NH2CH═NH2I (FAI) and CH3NH3I (MAI) with PbI2(DMSO)x complex in dimethyl sulfoxide (DMSO) and diethyl ether (DE) catalytic solvent system in the sequential two-step solution-process. The microscopic dynamics was characterized via the characterizations of in situ photoluminescence spectra. In addition, we found that the thermal stability of the perovskite films suffered from the residual solvent with high boiling point, for example, DMSO. The further DE treatment could promote the volatility process of DMSO and accelerate the crystallization process of perovskite films. The highest PCE over 19% with slight hysteresis effect was eventually obtained with a reproducible FA0.88MA0.12PbI3 solar cell, which displayed a constant power output within 100 s upon light soaking and stable PCE output within 30 d in the thermal stability test.

Hydrogenation of CO2 to Formic Acid with a Highly Active Ruthenium Acriphos Complex in DMSO and DMSO/Water

AbstractThe novel [Ru(Acriphos)(PPh3)(Cl)(PhCO2)] [1; Acriphos=4,5‐bis(diphenylphosphino)acridine] is an excellent precatalyst for the hydrogenation of CO2 to give formic acid in dimethyl sulfoxide (DMSO) and DMSO/H2O without the need for amine bases as co‐reagents. Turnover numbers (TONs) of up to 4200 and turnover frequencies (TOFs) of up to 260 h−1 were achieved, thus rendering 1 one of the most active catalysts for CO2 hydrogenations under additive‐free conditions reported to date. The thermodynamic stabilization of the reaction product by the reaction medium, through hydrogen bonds between formic acid and clusters of solvent or water, were rationalized by DFT calculations. The relatively low final concentration of formic acid obtained experimentally under catalytic conditions (0.33 mol L−1) was shown to be limited by product‐dependent catalyst inhibition rather than thermodynamic limits, and could be overcome by addition of small amounts of acetate buffer, thus leading to a maximum concentration of free formic acid of 1.27 mol L−1, which corresponds to optimized values of TON=16×103 and TOFavg≈103 h−1.

Hydrogenation of CO2 to Formic Acid with a Highly Active Ruthenium Acriphos Complex in DMSO and DMSO/Water.

The novel [Ru(Acriphos)(PPh3)(Cl)(PhCO2)] [1; Acriphos=4,5‐bis(diphenylphosphino)acridine] is an excellent precatalyst for the hydrogenation of CO2 to give formic acid in dimethyl sulfoxide (DMSO) and DMSO/H2O without the need for amine bases as co‐reagents. Turnover numbers (TONs) of up to 4200 and turnover frequencies (TOFs) of up to 260 h−1 were achieved, thus rendering 1 one of the most active catalysts for CO2 hydrogenations under additive‐free conditions reported to date. The thermodynamic stabilization of the reaction product by the reaction medium, through hydrogen bonds between formic acid and clusters of solvent or water, were rationalized by DFT calculations. The relatively low final concentration of formic acid obtained experimentally under catalytic conditions (0.33 mol L−1) was shown to be limited by product‐dependent catalyst inhibition rather than thermodynamic limits, and could be overcome by addition of small amounts of acetate buffer, thus leading to a maximum concentration of free formic acid of 1.27 mol L−1, which corresponds to optimized values of TON=16×103 and TOFavg≈103 h−1.

Efficient radiosynthesis and non-clinical safety tests of the TSPO radioprobe [18F]FEDAC: Prerequisites for clinical application

Introduction[18F]FEDAC ([18F]1) has potent binding affinity and selectivity for translocator protein (18kDa, TSPO), and has been used to noninvasively visualize neuroinflammation, lung inflammation, acute liver damage, nonalcoholic fatty liver disease, and liver fibrosis. We had previously synthesized [18F]1 in two steps: (i) preparation of [18F]fluoroethyl bromide and (ii) coupling of [18F]fluoroethyl bromide with the appropriate precursor (2) for labeling. In this study, to clinically utilize [18F]1 as a PET radiopharmaceutical and to transfer the production technique of [18F]1 to other PET centers, we simplified its preparation by using a direct, one-step, tosyloxy-for-fluorine substitution. We also performed an acute toxicity study as a major non-clinical safety test, and determined radiometabolites using human liver microsomes. Methods[18F]1 was prepared via direct 18F-fluorination by heating the corresponding tosylated derivative (3) with [18F]fluoride as its Kryptofix 222 complex in dimethyl sulfoxide at 110°C for 15min, following by HPLC purification. Non-clinical safety tests were performed for the extended single-dose toxicity study in rats, and for the in vitro metabolite analysis with human liver microsomal incubation. ResultsHigh quality batches of [18F]1, compatible with clinical applications, were obtained. At the end of irradiation, the decay-corrected radiochemical yield of [18F]1 using 1 and 5mg of precursor based on [18F]fluoride was 18.5±7.9% (n=10) and 52.0±5.8% (n=3), respectively. A single-dose of [18F]1 did not show toxicological effects for 14 days after the injection in male and female rats. In human liver microsomal incubations, [18F]1 was easily metabolized to [18F]desbenzyl-FEDAC ([18F]10) by CYPs (4.2% of parent compound left 60min after incubation). ConclusionWe successfully synthesized clinical grade batches of [18F]1 and verified the absence of innocuity of this radiotracer. [18F]1 will be used to first-in-human studies in our facility.

Synthesis, characterization and biological activities of semicarbazones and their copper complexes

Substituted semicarbazones/thiosemicarbazones and their copper complexes have been prepared and several single crystal structures examined. The copper complexes of these semicarbazone/thiosemicarbazones were prepared and several crystal structures examined. The single crystal X-ray structure of the pyridyl-substituted semicarbazone showed two types of copper complexes, a monomer and a dimer. We also found that the p-nitrophenyl semicarbazone formed a conventional ‘magic lantern’ acetate-bridged dimer. Electron Paramagnetic Resonance (EPR) of several of the copper complexes was consistent with the results of single crystal X-ray crystallography. The EPR spectra of the p-nitrophenyl semicarbazone copper complex in dimethylsulfoxide (DMSO) showed the presence of two species, confirming the structural information. Since thiosemicarbazones and semicarbazones have been reported to exhibit anticancer activity, we examined the anticancer activity of several of the derivatives reported in the present study and interestingly only the thiosemicarbazone showed activity while the semicarbazones were not active indicating that introduction of sulphur atom alters the biological profile of these thiosemicarbazones.

A novel schiff base ligand and its Ni(II) complex: synthesis and characterization

In this paper, synthesis of a novel Schiff base ligand based on bis(2-amino-4-pheny1-5-thiazolyl)disulfide and its corresponding Ni(II) complex was reported. This ligand was prepared through the formation of an imine bond between 2-hydroxy-1-naphthaldehyde and bis(2-amino-4-phenyl-5-thiazol)disulfide in absolute methanol as solvent. The characterizations were performed by FT-IR, 1H NMR, 13C NMR, elemental analysis, and single crystal X-ray analysis. In the molecular structure, the ligand possessed anti-conformation around –S–S– bond and monomeric moieties were linked into the chains through the C–H⋯O and π⋯π interactions. The reaction of the synthesized ligand with NiCl2 in methanol afforded the corresponding Ni(II) complex. The resulting product was further investigated by thermal gravimetric and differential thermal analysis, which confirmed the formation of desired polymeric complex. The electrochemical behavior and formation of Ni(II) complex in dimethyl sulfoxide (DMSO) solution were investigated by means of cyclic voltammetry and UV–Vis titration, respectively.

Synthesis, characterization, electropolymerization, and possible utilities of a new ruthenium–thiophene complex

ABSTRACT[RuCl2(p‐cymene)]2 was reacted with silver triflate and thiophene to give the sandwich complex [Ru(η5‐C4H4S)(η6‐p‐cymene)](PF6)2, which was characterized with NMR spectroscopy (1H‐NMR, 13C‐NMR, and 31P‐NMR), Fourier transform infrared spectroscopy, elemental analysis, and cyclic voltammetry. The behavior of this new complex in dimethyl sulfoxide with regard to the amount of absorbed water was investigated by both NMR and cyclic voltammetry; the formation of other species that affected electropolymerization was demonstrated. However, under optimal working conditions (in an anhydrous medium), the complex was successfully immobilized on a platinum electrode via an electro‐oxidation pathway through the thiophene ligand. This generated a highly stable, electroactive polymer film. Its response to the doping–undoping (charge–discharge) and redox processes, added to its high stability, promises important applications for this novel material. Moreover, this opens up the possibility of testing other compounds, such as [Ru(η5‐thiophene)(η6‐arene)], that were previously synthesized and reported for their electropolymerization and use as sensors according to their redox properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43559.

CdS quantum dots sensitized TiO2 nanotubes by matrix assisted pulsed laser evaporation method

Within this study a matrix assisted pulsed laser evaporation technique was employed for deposition of CdS quantum dots onto TiO2 nanotubes. The number of laser pulses and laser fluence were varied to control the amount of CdS deposit. TiO2 nanotubes were obtained via anodization technique of sputtered Ti film on FTO glass. For CdS synthesis, dimethyl sulfoxide (DMSO) was used as a matrix of the target which absorbs radiation of KrF* laser (λ=248nm), then evaporates enabling the deposition of CdS quantum dots dispersed into DMSO. This study showed that the size of the CdS nanoparticles synthetized in DMSO can be controlled with microwave treatment that causes the release of S2− ions from DMSO for creation of CdS nuclei and/or their further growth. The optimization of CdS synthesis is achieved by varying the duration of the microwave treatment and the microwave power. The obtained TiO2 photoanodes with different amounts of CdS were assembled with PbS cathodes and the polysulfide electrolyte was injected between. The influence of amount of CdS deposit and the microwave treatment of CdS on photovoltaic performance of the fabricated solar cells were analyzed under AM1.5. The results showed that microwave treatment produced a Cd(S)–DMSO complex onto CdS nanoparticles which led to a higher current density of the solar cells obtained using microwave treated CdS target. Also, the increase of CdS content by increasing the number of laser pulses provided the enhance of I–V characteristics of the solar cells.

Comparison of tetrel bonds and halogen bonds in complexes of DMSO with ZF3X (Z = C and Si; X = halogen)

A theoretical study of the complexes formed by dimethylsulfoxide (DMSO) with ZF3X (Z = C and Si; X = halogen) has been performed at the MP2/aug-cc-pVTZ level.

Synthesis, Characterization and Crystal Structure of a New Schiff Base Ligand from a Bis(Thiazoline) Template and Hydrolytic Cleavage of the Imine Bond Induced by a Co(II) Cation

The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H2L (1). Characterization of the ligand was performed by FT-IR, 1H NMR, 13C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO3)2·6H2O and CuCl2·2H2O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.

Vibrational studies of polar aprotic molecule in aromatic chemical and isotropic solvents: experimental and quantum chemical investigations

Raman spectroscopic technique has been used to study the intermolecular interactions and dynamics of SO, C―H and CSC stretching modes of dimethyl sulfoxide (DMSO) in binary mixtures using methyl benzene (MBN) and deuterated methyl benzene (MBNd) aromatic solvents. The Raman band of SO stretching mode has been deconvoluted into four distinct bands for neat DMSO as well as in binary mixtures. Deconvoluted bands in neat DMSO were assigned as monomer, cyclic out‐of‐phase, cyclic in‐phase and chain dimers having peak wavenumbers 1069.10, 1056.60, 1041.50 and 1027.30 cm−1 respectively. Peak wavenumber of SO stretching mode shows red shift, while peak wavenumbers of C―H and CSC stretching modes show blue shift with the increase in solvent concentration. The vibrational relaxation phenomena for all the stretching modes have been studied as a function of solvent concentration. Quantum‐chemical calculations have been carried out to gain more insight into the self‐association of DMSO and in interacting environment with the solvents using ab initio and density functional theory method. The ab initio basis set is HF/6‐31 + G (d, p) for the interacting system. The hydrogen bond complexes of DMSO with MBN and MBNd using IEF‐PCM model have been calculated using B3LYP functional and 6‐31 + G(d,p) basis sets. Theoretical calculations have been compared with the experimental findings and we obtained good coherence of the results. Copyright © 2015 John Wiley & Sons, Ltd.