Cyclopolymerization of diallylamine derivatives in dimethyl sulfoxide

Diallyl quaternary ammonium chlorides, bromides and N-alkyldiallylamine hydrochlorides were polymerized with ammonium persulfate (APS) in dimethyl sulfoxide (DMSO). The dependences of yield and molecular weight of polymers on polymerization conditions were examined and quaternary ammonium chlorides were found to have better polymerizability than bromides. The poly(diallyl quaternary ammonium chlorides) obtained with APS—DMSO system are expected to have quite high molecular weights, as determined from the measurement of limiting viscosity numbers of the polymers in NaCl aqueous solution.     

Radical Polymerization of Acrylamide in Aqueous-Dimethyl Sulfoxide Solutions in the Presence of Sodium Acetate

The kinetic features of nonisothermal polymerization of acrylamide in aqueous, mixed aqueousdimethyl sulfoxide, and DMSO solutions in the presence of potassium persulfate as initiator and sodium acetate as complexing agent were studied by differential thermal analysis.     

Isomeric Effects on Structures and Properties of Polyaminophenols Synthesized in Basic Medium

The oxidative chemical polymerizations of three isomers of aminophenol, ortho, meta, and para (PoAP, PmAP, PpAP) were performed in aqueous NaOH using ammonium persulfate (APS) as oxidant. Solubility tests for the synthesized polymers were performed in various solvents and it was found that all three polymers are soluble in DMSO and DMF. PpAP is soluble in aqueous strong acid, as well as in base, but PoAP is soluble in acid, whereas PmAP is soluble in base. The difference in their solubility is due to their structural difference, which can be supported by the proposed mechanisms of polymerizations. The film casting from the DMF or DMSO solution of PoAP and PpAP is difficult due to the presence of quinone impurity while casting of PmAP film from DMSO solution is possible. The intrinsic viscosities of the polymers were determined from the DMSO solution. The polymers were characterized by UV-VIS, FTIR and¹H-NMR spectroscopy and elemental analyses. From structural analysis, it is found that PoAP and PpAP do not contain π -electron conjugation due to ether linkage in the backbone chain. So, PoAP and PpAP do not show any conductivity like sulfuric acid doped PmAP.     

Graft copolymerization of methyl methacrylate onto curdlan

Graft copolymerization of methyl methacrylate onto curdlan was first investigated. In the graft copolymerization initiated by ammonium persulfate (APS) in DMSO under a homogeneous condition, the resulting graft copolymers had low molecular weights and low grafting percentages. However, the initiation by APS in water gave graft copolymers having relatively higher molecular weight ( ) and higher grafting percentage (548%) than those copolymers obtained by the homogeneous condition. When the graft copolymerization was carried out by cerium (IV) ammonium nitrate-HNO₃ initiation, the graft copolymer had the highest grafting percentage of 1620% without degradation of the curdlan backbone. The resulting graft copolymers were soluble in DMSO. The graft copolymers obtained by the cerium salt had narrow molecular weight distributions () compared with those by the APS catalyst in DMSO or water. The graft copolymers decomposed with sulfuric acid to isolate PMMAs, which molecular weights were larger than that of the corresponding homo-PMMAs. The structure of the grafted copolymers was characterized by IR, ¹³C NMR, DSC, and SEM. It was found that the graft copolymers exhibited the glass transition temperature (T_g), though curdlan had no T_g. As the grafting percentage increased, the T_g increased to reach 270°C, which was higher than the decomposition temperature of curdlan. The surface image of the grafted copolymers observed by SEM, showed smoothless compared with that of curdlan. It was also revealed that the graft copolymers having the grafting percentage of 1620% swelled in common organic solvents up to 4.5 times of the weight of the dry graft copolymer to form gels. © 1996 John Wiley & Sons, Inc.     

过硫酸盐活化高级氧化新技术

过硫酸盐在热、光、过渡金属催化等条件激活下产生强氧化性的硫酸根自由基·SO₄^-。基于·SO₄^-的过硫酸盐活化“高级氧化技术”在环境污染治理领域的应用,是刚刚发展起来的崭新的研究方向,具有广阔的应用前景。本文在分析其基本原理的基础上,综述了过硫酸盐活化技术在国内外土壤地下水有机污染原位修复、难降解有机废水处理等环境污染治理方面的研究进展,并就存在问题进行了研究展望。     

Unknown cis-[(DMSO)2ClCuII(μ-Cl)2CuIICl(DMSO)2] isomer obtained via new [Cu4Cl8(DMSO)8(hmta)] template complex

A missed cis isomeric form of a well-known trans-[CuCl₂(DMSO)₂]_n complex has been prepared via the tetranuclear [Cu₄Cl₈(DMSO)₈(hmta)] complex. Structurally, both complexes were found to be molecular i.e. [Cu₄Cl₈(DMSO)₈(hmta)] consists of isolated tetracoordinated hexamethylenetetramine molecules, whereas the cis-complex consists of isolated [(DMSO)₂ClCu^II(μ-Cl)₂Cu^IICl(DMSO)₂] clusters. It should also be noted that the cis-configuration of DMSO molecules in [(DMSO)₂ClCu^II(μ-Cl)₂Cu^IICl(DMSO)₂] was directly transferred from that of [Cu₄Cl₈(DMSO)₈(hmta)], while the trans-[CuCl₂(DMSO)₂]_n isomer was always formed as a final stable product.     

Polarographic Behaviour and Determination of Kinetic Parameters of Lead-Pamoate Complex in Dimethyl Sulfoxide

The polarography of lead ion in dimethyl sulfoxide (DMSO) was investigated in the DMSO concentration range 0–80 vol.%. The complex species identified were Pb₂(DMSO)⁴⁺₃, Pb(DMSO)²⁺₃ and Pb(DMSO)²⁺₆ in [DMSO]<10 vol.%, 10< [DMSO]<43 vol.% and [DMSO]>43 vol.%, respectively. In the presence of pamoic acid, the reduction of lead ion in DMSO was two-electron reversible diffusion-controlled at pH≤6.0, but it became irreversible at pH>6.0. The complex species identified was Pb(D_m)₂(P_m)₃(OH)^6? at pH>6.0. The rate constants of electro-reduction and electro-oxidation, activation energies were determined. The hydrolysis constants of lead ion in dimethyl sulfoxide concentration 40–70 vol.% at pH 4.5–6.0 were found to be of the order of 10^?6. The stability constants of the Pb(DMSO)²⁺₃ and Pb(DMSO)²⁺₀ were also determined to be of the orders of 10¹ and 10⁵, respectively.     

Preferential solvation of lysozyme by dimethyl sulfoxide in binary solutions of water and dimethyl sulfoxide

To reveal the denaturation mechanism of lysozyme by dimethyl sulfoxide (DMSO), thermal stability of lysozyme and its preferential solvation by DMSO in binary solutions of water and DMSO was studied by differential scanning calorimetry (DSC) and using densities of ternary solutions of water (1), DMSO (2) and lysozyme (3) at 298.15 K. A significant endothermic peak was observed in binary solutions of water and DMSO except for a solution with a mole fraction of DMSO (x ₂) of 0.4. As x ₂ was increased, the thermal denaturation temperature T _m decreased, but significant increases in changes in enthalpy and heat capacity for denaturation, ΔH _cal and ΔC _p, were observed at low x ₂ before decreasing. The obtained amount of preferential solvation of lysozyme by DMSO (∂g ₂/∂g ₃) was about 0.09 g g⁻¹ at low x ₂, indicating that DMSO molecules preferentially solvate lysozyme at low x ₂. In solutions with high x ₂, the amount of preferential solvation (∂g ₂/∂g ₃) decreased to negative values when lysozyme was denatured. These results indicated that DMSO molecules do not interact directly with lysozyme as denaturants such as guanidine hydrochloride and urea do. The DMSO molecules interact indirectly with lysozyme leading to denaturation, probably due to a strong interaction between water and DMSO molecules.     

Polarographic Studies of the Reduction of Sn(II) in Dimethylsulphoxide and its Mixtures with Water and Acetonitrile

Abstract

The polarographic reduction of Sn(II) in DMSO, H₂O-DMSO and AN-DMSO mixtures was characterized as being reversible. When the reduction was carried out in an the process was found to be irreversible and in this case the kinetic parameters were determined by Meites and Israel's method. the effect of DMSO on the reduction of Sn(II) in an shows that the Sn(II) forms six successive complexes with DMSO, whose stability constants were determined by Deford and Hume's method.

The Walden product was determined for the mixtures under study. In AN-DMSO it decreases up to 20 vol.% DMSO, and from there remains approximately constant. In the H₂O-DMSO mixtures the Walden product passes through a broad minimum between 60 and 70 vol.% DMSO. the free energy of transfer in the hydro-organic mixture changes gradually with the increase in DMSO content, whereas in the AN-DMSO mixture this energy increases rapidly in very low DMSO content mixtures.     

Excess partial molar enthalpies,entropies, Gibbs energies,and volumes in aqueous dimethylsulfoxide

The excess partial molar enthalpies, the vapor pressures, and the densities of dimethylsulfoxide (DMSO)–H₂O mixtures were measured and the excess partial molar Gibbs energies and the partial molar volumes were calculated for DMSO and for H₂O. The values of the excess partial molar Gibbs energies for both DMSO and H₂O are negative over the entire composition range. The results for the water-rich region indicated that the presence of DMSO enhances the hydrogen bond network of H₂O. Unlike monohydric alcohols, however, the solute-solute interaction is repulsive in terms of the Gibbs energy. This was a result of the fact that the repulsion among solutes in terms of enthalpy surpassed the attraction in terms of entropy. The data in the DMSO-rich region suggest that DMSO molecules form clusters which protect H₂O molecules from exposure to the nonpolar alkyl groups of DMSO.     

Macrocyclic Polyether Phase Transfer Catalysts for Free Radical Polymerization of Acrolein

Macrocyclic polyethers, e.g., crown ethers and cryptands, were prepared and employed as phase transfer catalysts for free radical polymerization of acrolein, a vinyl monomer, with persulfates (S₂O₈^2–) as initiators. The catalytic abilities of various macrocyclic polyethers as catalysts for the free radical polymerization of acrolein were found to be in the order: benzo‐15‐crown‐5 > dibenzo‐18‐crown‐6 > 12‐crown‐4 > 15‐crown‐5 > 18‐crown‐6 > cryptand‐22 with sodium persulfate (Na₂S₂O₈) as initiator. Sodium persulfate proved to be a better initiator than ammonium persulfate or potassium persulfate with benzo‐15‐crown‐5 as a catalyst. Effects of solvents and temperature on the catalytic polymerization were also investigated. The polymerization rates in various solvents were in the order: dioxane > benzene > acetonitrile > acetone > dichloromethane > hexane > water. Comparison between bulk polymerization and solution polymerization was also made. Higher polymerization rate was observed at higher temperature. The molecular weights of polyacrolein and the conversion of monomer in reaction period were determined with gel permeation chromatography and ultra‐violet spectrophotometry, respectively. Concentration effects of crown ether and initiator were also investigated and discussed.     

Osmium dimethyl sulfoxide complexes: Synthesis and properties of [H(dmso)2][OsIII(dmso)2Br4]

The reaction of H₂[OsBr₆] with DMSO in ethanol solution resulted in DMSO complex [H(dmso-O)₂][Os^III(dmso-S)₂Br₄] (1) described previously as an intermediate product in the reaction of K₂[OsBr₆] with DMSO and characterized by EAS and ESR spectra. The coordination of DMSO molecules was established by IR and ¹H and ¹³C NMR spectroscopy. The oxidation state of osmium and trans arrangement of DMSO molecules in the anion were established by ESR. The behavior of complex 1 in solutions was studied by EAS, ESR, and mass-spectrometry: a displacement of Br^? ions accompanied by the reduction of osmium to oxidation state +2 occurs in DMSO, a solvation with displacement of DMSO molecules is observed at the first stage in water and methanol (rate constants 2.3 × 10^?4 and 1.7 × 10^?3 s^?1, respectively), the sequential substitution of DMSO molecules and osmium oxidation to form [Os^IVBr₆]_2? ions takes place in 4 mol/L HBr.     

Determination of dimethyl sulfoxide and dimethyl sulfone in urine by gas chromatography–mass spectrometry after preparation using 2,2‐dimethoxypropane

A method for routinely determination of dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO₂) in human urine was developed using gas chromatography–mass spectrometry. The urine sample was treated with 2,2‐dimethoxypropane (DMP) and hydrochloric acid for efficient removal of water, which causes degradation of the vacuum level in mass spectrometer and shortens the life‐time of the column. Experimental DMP reaction parameters, such as hydrochloric acid concentration, DMP–urine ratio, reaction temperature and reaction time, were optimized for urine. Hexadeuterated DMSO was used as an internal standard. The recoveries of DMSO and DMSO₂ from urine were 97–104 and 98–116%, respectively. The calibration curves showed linearity in the range of 0.15–54.45 mg/L for DMSO and 0.19–50.10 mg/L for DMSO₂. The limits of detection of DMSO and DMSO₂ were 0.04 and 0.06 mg/L, respectively. The relative standard deviations of intra‐day and inter‐day were 0.2–3.4% for DMSO and 0.4–2.4% for DMSO₂. The proposed method may be useful for the biological monitoring of workers exposed to DMSO in their occupational environment. Copyright © 2009 John Wiley & Sons, Ltd.     

Emulsion polymerization of styrene. III. Effect of Ti(III) and Cl(1) on the polymerization of styrene initiated by potassium persulfate

The emulsion polymerization of styrene initiated by potassium persulfate catalyzed by Ti⁺³ ions was studied. Two sources of Ti⁺³ ions were used: the titanium trichloride and titanium sulfate. It was found that the titanium ions used in conjunction with potassium persulfate decrease both the reaction rate and the average molecular weight. An even greater drop of reaction rate was noted when chlorine anions (TiCl₃) were present. The presence of these ions had a stabilizing effect on the polydispersity.     

Polymerization of pyrrole by potassium persulfate

Pyrrole reacted with potassium persulfate in aqueous media to form polymers or “pyrrole blacks.” The structure and molecular weight depend on the initial pyrrole/K₂S₂O₈ ratio. An ESR line due to trapped electrons or free radical ions appeared at g = 2.0036 (width 3.6 G) in all products and its intensity decreased with an increase in initial concentration of potassium persulfate.     

Synthesis,structure, and electrochemistry of mer[RuCl3(DMSO–S)(DMSO–O)(py)]

Reaction of mer-[RuCl₃(DMSO–S)₂(DMSO–O] (1) with pyridine (py) in dichloromethane yields mer-[RuCl₃(DMSO–S)(DMSO–O)(py)] (2). A single crystal suitable for X-ray diffraction was obtained by recrystalization with dichloromethane and diethyl ether. X-ray diffraction analysis revealed an unusual case in which two independent molecules (2a and 2b) are present in the asymmetric unit cell. Both molecules have distorted octahedral geometry in which DMSO is bound through oxygen and sulfur. Density functional theory (DFT) calculations were performed for 2a and 2b in gas phase to investigate bonding shown by the two DMSO ligands. Optimizations were done on both DMSO ligands bonded through S, both DMSO ligands bonded through O, one DMSO bonded through O, and the other through S but opposite to the actual molecule. The energy differences of the optimized structures were calculated.     

Effect of stirring on cellulose graft copolymerization. IV. Grafting of styrene by initiator systems involving potassium persulfate

Dissolving pulp and its partially xanthated derivative were grafted with styrene, using either the Fe²⁺?K₂S₂O₈ redox system of potassium persulfate alone as initiators. The conversion of styrene to both copolymer and homopolymer was found to be influenced by agitator speed. The effect of stirring was much more pronounced with the xanthated substrate in that a welldefined conversion maximum was observed at the same agitation speed for both total polymer and copolymer. Grafting onto dissolving pulp with the redox initiator also showed a maximum, but a maximum total polymer and maximum copolymer were located at different agitator speeds. Grafting of styrene onto dissolving pulp initiated by potassium persulfate was almost independent of stirring in the 0–910 rpm range.     

Phosphonobetaine/sulfur dioxide copolymer by Butler’s cyclopolymerization process

The zwitterionic monomer, ethyl 3-(N,N-diallylammonio)propanephosphonate and sulfur dioxide were cyclocopolymerized in DMSO using azobisisobutyronitrile or ammonium persulfate as initiators to afford a pH-responsive polyphosphonobetaine/SO₂ (PPB/SO₂) copolymer. The polymers, on treatment with HCl and NaOH, gave the aqueous solutions of the corresponding cationic polyphosphononic acid (CPP) and anionic polyphosphonate (APP). The solution properties of the PPB having two pH-responsive functionalities were investigated in detail by potentiometric and viscometric techniques. Basicity constants of the amine and phosphonate groups in APP were found to be “apparent” and as such follow the modified Henderson–Hasselbalch equation. The incorporation of SO₂ moiety has resulted in the decrease of basicity constant of the nitrogens in the copolymer by staggering ?2 units of log K in compare to that of the corresponding homopolymer. The basicity difference is expected to have an effect on the chelating properties of the polymers. In contrast to many polycarbo- and -sulfobetaines, the PPB was all found to be soluble in salt-free water as well as in salt (including Ca²⁺ and Li⁺)-added solutions. The PPB demonstrated ‘antipolyelectrolyte’ viscosity behavior and found to have higher viscosity values in LiCl than in NaCl or NaI.     

Inactivation Kinetics of Polyphenol Oxidase from Pupae of Blowfly (Sarcophaga bullata) in the Dimethyl Sulfoxide Solution

The effects of dimethyl sulfoxide (DMSO) on the activity of polyphenol oxidase (PPO, EC 1.14.18.1) from blowfly pupae for the oxidation of l-3,4-dihydroxyphenylalanine were studied. The results showed that low concentrations of DMSO could lead to reversible inactivation to the enzyme. The IC₅₀ value, the inactivator concentration leading to 50% activity lost, was estimated to be 2.35 M. Inactivation of the enzyme by DMSO was classified as mixed type. The kinetics of inactivation of PPO from blowfly pupae in the low concentrations of DMSO solution was studied using the kinetic method of the substrate reaction. The rate constants of inactivation were determined. The results show that k ₊₀ was much larger than k _{+ 0}￠ k_{ + 0}^\prime , indicating that the free enzyme molecule was more fragile than the enzyme–substrate complex in the DMSO solution. It was suggested that the presence of the substrate offers marked protection of this enzyme against inactivation by DMSO.     

Insights into the cooperativity between multiple interactions of dimethyl sulfoxide with carbon dioxide and water

Interactions of dimethyl sulfoxide with carbon dioxide and water molecules which induce 18 significantly stable complexes are thoroughly investigated. An addition of CO₂ or H₂O molecules into the DMSO⋯1CO₂ and DMSO⋯1H₂O systems leads to an increase in the stability of the resulting complexes, in which it is larger for a H₂O addition than a CO₂. The overall stabilization energy of the DMSO⋯1,2CO₂ is mainly contributed by the S=O⋯C Lewis acid–base interaction, whereas the O − H⋯O hydrogen bond plays a significant role in stabilizing complexes of DMSO⋯1,2H₂O and DMSO⋯1CO₂⋯1H₂O. Remarkably, the complexes of DMSO⋯2H₂O are found to be more stable than DMSO⋯1CO₂⋯1H₂O and DMSO⋯2CO₂. The level of the cooperativity of multiple interactions in ternary complexes tends to decrease in going from DMSO⋯2H₂O to DMSO⋯1CO₂⋯1H₂O and finally to DMSO⋯2CO₂. It is generally found that the red shift of the O − H bond involved in an O − H⋯O hydrogen bond increases while the blue shift of a C − H bond in a C − H⋯O hydrogen bond decreases when a cooperative effect occurs in ternary complexes as compared to those of the corresponding binary complexes. © 2018 Wiley Periodicals, Inc.