Dimethyl Sulfoxide Molecules Research Articles

Kinetic study of the intercalation process of dimethylsulfoxide in kaolinite

A kinetic study of the intercalation reaction of dimethylsulfoxide (DMSO) into the layers of kaolinite was carried out. Several kaolinite–DMSO mixtures were analyzed at four temperatures (60, 50, 45 and 40°C). Structural characterization was done by X-ray diffraction (XRD). The intercalation reaction was followed by XRD of the kaolinite–DMSO intercalates at different reaction times and temperatures. A kinetic analysis of the process was performed considering a two-step simple mechanism for consecutive reactions: ingress of DMSO molecules into the kaolinite galleries and subsequent rotation of DMSO molecules. Finally, the activation energies of the two steps proposed for the global intercalation process were estimated.

Dependence of the enthalpies of alanyl-alanine dissolution on the composition of mixed water + acetone and water + DMSO solvents at 298.15 K

The enthalpies of dissolution of two dipeptides, DL-α-alanyl-β-alanine and β-alanyl-β-alanine, in mixed solvents H2O + acetone (AC) and H2O + dimethyl sulfoxide (DMSO) are measured via calorimetry at an organic component concentration of x 2 = 0–0.25 mole fraction at 298.15 K. The standard enthalpies of dissolution (Δsol H po) and the transfer (Δtr H po) of dipeptides from water to the mixed solvent and the enthalpic coefficients of pairwise interactions (h xy ) with AC and DMSO molecules are calculated from these data. The effect the composition of aqueous organic mixtures has on the enthalpy characteristics of the dissolution of DL-α-alanyl-β-alanine and β-alanyl-β-alanine is considered. A comparative analysis of h xy values is performed for alanine dipeptides in the investigated mixed solvents.

Crystal structure of catena-poly[calcium-di-μ3-benzoato-κ(6) O,O':O-μ2-(dimethyl sulfoxide)-κ(2) O:O

In the title complex, [Ca(C7H5O2)2(C2H6OS)] n , the Ca(2+) ion (site symmetry m..) is surrounded by eight O atoms, six from two bridging-chelating tridentate benzoate carboxyl groups and two from a bridging dimethyl sulfoxide mol-ecule (point group symmetry m..), giving an irregular coordination geometry [Ca-O bond length range = 2.345 (2)-2.524 (2) Å]. One-dimensional coordination complex chains extending parallel to c are generated in which the triply μ2-O-bridged Ca(2+) cations are separated by 3.6401 (5) Å. In the crystal, weak intra-chain C-H⋯π hydrogen bonds are present between the methyl H atoms of the dimethyl sulfoxide mol-ecules as donors and the aromatic rings as acceptors [C-H⋯Cg = 3.790 (4) Å].

The effect of dimethylsulfoxide on absorption and fluorescence spectra of aqueous solutions of acridine orange base

The photophysical properties of aqueous solutions of acridine orange base (AOB) in wide concentration range of dimethylsulfoxide (DMSO) were studied by using absorption and steady-state fluorescence spectroscopy techniques at room temperature. The absorption spectrum of acridine orange in water shows two bands at 468 and 490nm which were attributed to the dimer ((AOBH)22+) and monomer (AOBH+) species respectively. In DMSO solution for the same AOB concentration only the basic form was detected with the band at 428nm. The addition of DMSO to AOB aqueous solution leads to the decrease of absorption band at 490nm and the new absorption band increases at 428nm due to deprotonated (basic) form of AO and the first isosbestic point occurs at 450nm. The evolution of isosbestic point reveals that an other equilibrium, due to the self-association of DMSO molecules takes place. From the steady-state fluorescence spectra Stokes shifts were calculated for AOB in aqueous and DMSO solutions. The addition of DMSO into the aqueous solution induced the enhancement in the fluorescence intensity of the dye compared to those in water.

Trapping of Charged Gold Adatoms by Dimethyl Sulfoxide on a Gold Surface.

We report the formation of dimethyl sulfoxide (DMSO) molecular complexes on Au(111) enabled by native gold adatoms unusually linking the molecules via a bonding of ionic nature, yielding a mutual stabilization between molecules and adatom(s). DMSO is a widely used polar, aprotic solvent whose interaction with metal surfaces is not fully understood. By combining X-ray photoelectron spectroscopy, low temperature scanning tunneling microscopy, and density functional theory (DFT) calculations, we show that DMSO molecules form complexes made by up to four molecules arranged with adjacent oxygen terminations. DFT calculations reveal that most of the observed structures are accurately reproduced if, and only if, the negatively charged oxygen terminations are linked by one or two positively charged Au adatoms. A similar behavior was previously observed only in nonstoichiometric organic salt layers, fabricated using linkage alkali atoms and strongly electronegative molecules. These findings suggest a motif for anchoring organic adlayers of polar molecules on metal substrates and also provide nanoscale insight into the interaction of DMSO with gold.

Effect of surfactant SDS on DMSO transport across water/hexane interface by molecular dynamics simulation

Solute transport behavior across liquid–liquid interfaces plays important roles in many chemical engineering processes and usually occurs in the presence of surfactants. In this work, we report a full all-atom molecular dynamics simulation study of dimethyl sulfoxide (DMSO) crossing a water/hexane interface in different concentrations of sodium dodecylsulfate (SDS). By analyzing various properties, ranging from the configuration and energetic behaviors to the dynamic characteristics, we conclude that the presence of SDS has multiple non-trivial effects: (1) the association of SDS at the interface drives the interfacial region wider and decreases the interfacial tension with an almost linear dependence on SDS concentration; (2) higher SDS concentrations result in both a lower self-diffusion coefficient for DMSO and a smaller resistance force to DMSO moving out of the interfacial region, causing the exchange of DMSO between the interface and bulk region to become more frequent; and (3) the transition of the orientation preference of DMSO molecules passing from the interface to the water-rich phase vanishes. Current simulation studies examining the molecular level provide helpful insights for understanding the influence of surfactants on solute transport.

Crystal structure of 6-amino-4-(3-bromo-4-meth-oxy-phen-yl)-3-methyl-2,4-di-hydro-pyrano[2,3-c]pyrazole-5-carbo-nitrile dimethyl sulfoxide monosolvate.

In the pyrazole mol­ecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between the benzene ring and the mean plane of the di­hydro­pyrano[2,3-c]pyrazole ring system [r.m.s deviation = 0.031 (2) Å] is 86.71 (14)°. In the crystal, the pyrazole mol­ecules are linked by N—H⋯N hydrogen bonds, forming a layer parallel to (10-1). The pyrazole and dimethyl sulfoxide mol­ecules are connected by an N—H⋯O hydrogen bond.

Pyrolytic synthesis and luminescence of porous lanthanide Eu-MOF.

A lanthanide metal coordination polymer [Eu2(BDC)3(DMSO)(H2O)] was synthesized by the reaction of europium oxide with benzene-1,3-dicarboxylic acid (H2BDC) in a mixed solution of dimethyl sulfoxide (DMSO) and water under hydrothermal conditions. The crystal structure of Eu2(BDC)3(DMSO)(H2O) was characterized by X-ray diffraction (XRD). Thermo-gravimetric analysis of Eu2(BDC)3(DMSO)(H2O) indicated that coordinated DMSO and H2O molecules could be removed to create Eu2(BDC)3(DMSO)(H2O)-py with permanent microporosity, which was also verified by powder XRD (PXRD) and elemental analysis. Both Eu2(BDC)3(DMSO)(H2O) and Eu2(BDC)3(DMSO)(H2O)-py showed mainly Eu-based luminescence and had characteristic emissions in the range 550-700 nm.

Improving of the adsorption capacity of halloysite nanotubes intercalated with dimethyl sulfoxide

Algerian halloysite intercalated with dimethyl sulfoxide (DMSO) was prepared. The starting (H) and resulting (H-DMSO) materials were characterized by X-ray powder diffraction, Fourier transformed infrared spectroscopy, thermal analysis, transmission electron microscopy, pore-size distribution analysis, and employed as crystal violet (CV+) adsorbents from aqueous solutions. Intercalation reaches a rate of 95% and increases the basal spacing to 11.2 Å. (CH3)2SO interacts with the inner surface hydroxyls of halloysite through new hydrogen bonds with the S=O groups. The release of DMSO occurs in two phases: a partial elimination at 195 °C and a second part due to the DMSO combustion at 277 °C. The TEM image of H-DMSO reveals halloysite nanotubes (HNTs) polydisperse in length and diameter. A heterogeneous distribution in the nanotube size was highlighted with pore diameters of 10–11, 20.6, 28.6, and 37.0 nm, in correlation with transmission electron microscopy. The Redlich–Peterson equation describes efficiently the CV+ adsorption onto the modified sample. H-DMSO adsorbs 93.6 against 50.9 mg g−1 for the starting material. This improving of the adsorption capacity of DMSO-intercalated HNTs, was explained via the behavior of the intercalated DMSO molecules. Intercalation constitutes a key procedure for developing new nanocomposites, attractive in technological applications, such as effective adsorbents.

Electrospinning of magnesium-ion linked binder-less PEDOT:PSS nanofibers for sensing organic gases

Controlled and continuous electrospinning of approximately pure poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) nanofibers has been successfully realized for the first time by alternating the great amount of conventional carrier polymers with only slight doping of magnesium nitrate which acts as a polymer cross-linker for significantly enhancing the entanglement of PEDOT:PSS. In contrast to the less response of the bulky PEDOT:PSS film, the electrospun PEDOT:PSS nanofibers exhibit remarkably high sensitivities and responding speeds in respectively sensing gas molecules of dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and propylene carbonate (PC).

Preparation of kaolinite nanotubes by a solvothermal method

Kaolinite nanotubes were prepared by intercalation and solvothermal reactions using pristine kaolin as a starting material. Firstly, an intercalation compound of kaolinite/dimethyl sulfoxide was prepared as a precursor. Then, kaolinite/methanol (KM) was achieved by replacing dimethyl sulfoxide with methanol through solvothermal reaction at 100°C. Dimethyl sulfoxide molecules can be replaced mostly when the reaction time was 2h, and the intercalation ratio of KM compound reached 97.9% for the reaction time of 24h. Finally, the kaolinite nanotubes were achieved by the solvothermal reaction of the KM compound and methanol solution of CTAC (1M) at 100°C for 24h. XRD, IR, SEM, and N2 sorption measurements were used to characterize the as-prepared samples. It is found that the kaolinite nanotubes had a specific surface area of 45.44m2/g. The length of the nanotubes is about 300–2000nm and the internal diameter and external diameter is about 15–55nm and 40–80nm, respectively.

Combined experimental and theoretical investigation of interactions between kaolinite inner surface and intercalated dimethyl sulfoxide

Kaolinite intercalation complex with dimethyl sulfoxide (DMSO) was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry–differential scanning calorimetry (TG–DSC) combined with molecular dynamics simulation. The bands assigned to the OH stretching of inner surface of kaolinite were significantly perturbed after intercalation of DMSO into kaolinite. Additionally, the bands attributed to the vibration of gibbsite-like layers of kaolinite shifted to the lower wave number, indicating that the intercalated DMSO were strongly hydrogen bonded to the alumina octahedral surface of kaolinite. The slightly decreased intensity of 1031cm−1 and 1016cm−1 band due to the in-plane vibration of SiO of kaolinite revealed that some DMSO molecules formed weak hydrogen bonds with the silicon tetrahedral surface of kaolinite. Based on the TG result of kaolinite–DMSO intercalation complex, the formula of A12Si2O5(OH)4(DMSO)0.7 was obtained, with which the kaolinite–DMSO complex model was constructed. The molecular dynamics simulation of kaolinite–DMSO complex directly confirmed the monolayer structure of DMSO in interlayer space of kaolinite, where the DMSO arranged almost parallel with kaolinite basal surface with all methyl groups being distributed near the interlayer midplane and oxygen atoms orienting toward to the alumina octahedral surface. The radial distribution function between kaolinite and intercalated DMSO verified the strong hydrogen bonds forming between hydroxyl hydrogen atoms of alumina octahedral surface and oxygen atoms of DMSO. Moreover, some methyl groups of DMSO were weakly hydrogen bonded to the oxygen atoms of silicon tetrahedral surface through the hydrogen atoms. The mean square displacement of DMSO oxygen atoms and hydrogen atoms in z direction kept unchanged during the simulation time because of the hydrogen-bond interaction between inner surface of kaolinite and DMSO, which constrained the mobility of intercalated DMSO in the direction normal to the kaolinite basal surface.

Phase Equilibria and Ionic Solvation in the Lithium Tetrafluoroborate–Dimethylsulfoxide System

The phase diagram and electrical conductivity isotherms for the lithium tetrafluoroborate (LiBF4)–dimethylsulfoxide (DMSO) system and Raman spectra of DMSO and the LiBF4–DMSO solution were studied. Spectroscopic signatures of a H-bond between DMSO and BF4 − ions were found. The bonds of Li+ ions to the solvent were stronger than the bonds in DMSO dimers because formation of the solvate destroyed dimeric DMSO molecules. The τω values for DMSO molecules in the Li+-ion solvate shell of the LiBF4–DMSO system were similar to those for associated solvent molecules.

Structural, energetic, and electronic properties of La(III)-dimethyl sulfoxide clusters.

By using accurate density functional theory calculations, we have studied the cluster complexes of a La(3+) ion interacting with a small number of dimethyl sulfoxide (DMSO) molecules of growing size (from 1 to 12). Extended structural, energetic, and electronic structure analyses have been performed to provide a complete picture of the physical properties that are the basis of the interaction of La(III) with DMSO. Recent experimental data in the solid and liquid phase have suggested a coordination number of 8 DMSO molecules with a square antiprism geometry arranged similarly in the liquid and crystalline phases. By using a cluster approach on the La(3+)(DMSO)n gas phase isolated structures, we have found that the 8-fold geometry, albeit less regular than in the crystal, is probably the most stable cluster. Furthermore, we provide new evidence of a 9-fold complexation geometric arrangement that is competitive (at least energetically) with the 8-fold one and that might suggest the existence of transient structures with higher coordination numbers in the liquid phase.

Crystal structure of a one-dimensional helical-type silver(I) coordination polymer: catena-poly[[silver(I)-μ-N-(pyridin-4-ylmeth-yl)pyridine-3-amine-κ(2) N:N'] nitrate dimethyl sulfoxide disolvate

The asymmetric unit of the title compound, {[Ag(C11H11N3)]NO3·2(CH3)2SO} n , comprises one Ag(I) atom, one N-(pyridine-4-ylmeth-yl)pyridine-3-amine ligand, one nitrate anion and two dimethyl sulfoxide mol-ecules. The Ag(I) atoms are bridged by two pyridine N atoms from two symmetry-related ligands, forming a helical chain and adopting a slightly distorted linear coordination geometry [N-Ag-N = 175.37 (8)°]. The helical chain, with a pitch length of 16.7871 (8) Å, propagates along the b-axis direction. In the crystal, symmetry-related right- and left-handed helical chains are alternately arranged via Ag⋯Ag inter-actions [3.4145 (4) Å] and π-π stacking inter-actions [centroid-centroid distance = 3.650 (2) Å], resulting in the formation of a two-dimensional supra-molecular network extending parallel to (100). Weak Ag⋯O [2.775 (2), 3.169 (4) and 2.690 (2) Å] inter-actions, as well as several N-H⋯O and C-H⋯O hydrogen-bonding inter-actions, contribute to the stabilization of the crystal structure. Parts of the dimethyl sulfoxide solvent molecule are disordered over two sets of sites in a 0.937 (3):0.063 (3) ratio.

Hydrogen-bonded complexes between dimethyl sulfoxide and monoprotic acids: molecular properties and IR spectroscopy.

MP2/6-31++G(d,p) and DFT B3LYP/6-31++G(d,p) calculations were performed of the structure, binding energies, and vibrational modes of complexes between dimethyl sulfoxide (DMSO) as a proton acceptor and monoprotic linear acids HX (X=F, Cl, CN) as well as monoprotic carboxylic acids HOOCR (R = -H, -CH3, -C6H5) in 1:1 and 1:2 stoichiometric ratios. The results show that two different structures are possible in the 1:2 ratio: in the first, the DMSO molecule interacts with both acid molecules (leading to a "Y" structure); in the second, the DMSO interacts with only one monoprotic acid. The second structure shows a lower stability per hydrogen bond. The spontaneities of the reactions to form the 1:1 and 1:2 complexes are greatly influenced by the X group of the linear acid. With the exception of HCN, all the reactions are spontaneous. In the 1:2 complexes with Y structure, we observed that the hydrogen atoms of the linear acid are coupled in symmetric and asymmetric modes, while this type of coupling is absent from the other 1:2 complexes.

Clustering and Solvation of Cobalt Nanostructures in Dimethyl Sulfoxide

It has been reported that the molecule dimethyl sulfoxide (DMSO) can be effectively utilized as both a stabilizing ligand and a solvent during cobalt (Co) nanoparticle synthesis. Accordingly, stabilization of the nanostructures is provided by electrostatic contributions from the molecular sulfoxide components. This paper reports the synthesis of Co nanoparticles and nanoclusters (i.e., nanoparticle aggregates) of various sizes in DMSO at 25, 50, and 150 °C. This study illustrates that the size of the resulting Co nanoclusters is a direct function of the synthesis temperature. Moreover, these Co nanoclusters are composed of smaller Co nanoparticles that preferentially aggregate at increased temperatures during synthesis, where the largest nanoclusters are constructed at the highest synthesis temperatures. Furthermore, it is demonstrated that the smaller Co nanoparticles that makeup the larger Co nanoclusters can be liberated in solution upon the addition of various cosolvents.

Probe dependent anomalies in the solvation dynamics of coumarin dyes in dimethyl sulfoxide-glycerol binary solvent: confirming the local environments are different for coumarin dyes.

The solvation dynamics of coumarin dyes in dimethyl sulfoxide (DMSO)-glycerol (GLY) binary mixtures were studied across the GLY concentrations. Three coumarin dyes with widely different hydrophobicities were used for probing the entire polarity regions of this solvent mixture. Multiple anomalous concentration regions with significantly slow solvation times were detected from all three coumarin dyes. However, their precise positions were found to be probe molecule dependent. The solvation dynamics of the moderately hydrophobic dye coumarin 480 (C480) maintain a plateau region with a similar solvation time (∼550 ps) with the increase in GLY concentration until X(GLY) (the mole fraction of glycerol) reaches 0.5. This plateau region is followed by a sudden slowdown (to ∼975 ps) on the addition of more GLY to the DMSO-GLY mixture, and then this slow region persists from X(GLY)∼ 0.55 to 0.65 (peak at 0.6). On further addition of GLY (X(GLY) > 0.7), the solvation dynamics again become slower to ∼828 ps (at X(GLY)∼ 0.8) from ∼612 ps (at X(GLY)∼ 0.7). For very high GLY-content samples (X(GLY) > 0.85), the solvation times remain similar on further changes of the GLY concentrations. In contrast to C480, the most hydrophobic dye coumarin 153 (C153) shows a linear increase of solvation time in the DMSO-GLY mixture, from 102 ps (at X(GLY)∼ 0.1) to 946 ps (at X(GLY)∼ 0.9) with increase in GLY concentration, except for the concentration region, X(GLY)∼ 0.45-0.55 (peak at 0.5), where a substantial slowdown of the solvation time is observed. The highly hydrophilic probe coumarin 343 (C343) demonstrates multiple concentration regions (X(GLY)∼ 0.05-0.10, 0.25-0.35 and 0.55-0.65) where the solvation dynamics are significantly retarded. The presence of probe dependent anomalies in the DMSO-GLY mixture is a clear indication of there being different locations of probe molecules within this solvent mixture. We assume that the slowing-down of the solvation time could be a reflection of several aspects, including the inherit inhomogeneity, intriguing structural transformations in the DMSO-GLY mixture, percolation among DMSO molecules and network structure formation, where DMSO:GLY complexes contribute to the dynamical features.

Copper(II) complexes with 3-hydroxyquinoxaline-2-carboxylic acid

Hydrothermal and mechanochemical syntheses are extensively used to obtain metal coordination polymers of different dimensionalities. Transition metal complexes with carboxylate based ligands e. g. 3-hydroxyquinoxaline-2-carboxylic acid (3-OHquinoxH) are interesting due to the possible formation of porous structures suitable for gas storage and separation. 1D coordination polymer {[Cu2(3-OHquinox)2(SO4)(H2O)2]·4DMSO}n (1) was obtained by reaction of CuSO4and 3-OHquinoxH in dimethyl sulfoxide (DMSO) solution at room temperature, while mononuclear complex [Cu(3-OHquinox)2(H2O)2]·2DMSO (2) was formed under hydrothermal conditions. The X-ray crystal structure analysis revealed two differently coordinated Cu(II) ions in 1 (see figure). The first Cu(II) ion in 1 is octahedrally coordinated by two bridging O,O'-bidentate 3-OHquinox ligands and two water molecules in trans position, and the second Cu(II) ion by two bridging N,O'-bidentate 3-OHquinox ligands and one O,O'-bidentate sulfate ion. The Cu(II) ion in 2 is octahedrally coordinated by two N,O'-bidentate 3-OHquinox ligands and two water molecules in trans position. The reaction mixture was also grinded in a ball mill in the presence of H2O, DMSO or their mixture and the products were identified by powder X-ray diffraction (PXRD). The grinding under these conditions could not be used to prepare pure 1 nor 2, but rather a mixture of both 1, 2, reactants and new, still unidentified, phase. The complex 2 was also studied by DFT methods. The hypothetical complex with two O-bound DMSO molecules is more stable than 2 by 2.9 kcal/mol. The preference for the formation of 2, with two coordinated water molecules, must be assigned to the hydrogen bonds between coordinated water and crystallization DMSO molecules in the crystal structure of 2.

Crystal structure of bis-{μ-4-methyl-N'-[3-(oxido-imino)-butan-2-yl-idene]benzene-sulfono-hydrazidato}bis-[(dimethyl sulfoxide-κO)copper(II)

In the title compound, [Cu2(C11H13N3O3S)2(C2H6OS)2], the CuII cation is N,N′,O-chelated by a deprotonated hy­droxy­imino-tosyl­hydrazone ligand and coordinated by a dimethyl sulfoxide mol­ecule. One O atom from the adjacent hy­droxy­imino-tosyl­hydrazone ligand bridges the CuII cation, forming the centrosymmetric dimeric complex. The cation is in an overall distorted N2O3 square-pyramidal coordination environment. The methyl­benzene ring is twisted with respect to the hydrazine fragment, with a dihedral angle of 89.54 (9)° between the planes. An intra­molecular C—H⋯O hydrogen bond occurs. In the crystal, mol­ecules are linked by weak C—H⋯O and C—H⋯S inter­actions. Weak π–π stacking is also observed between parallel benzene rings of adjacent mol­ecules, the centroid–centroid distance being 3.9592 (17) Å.