Sulfamic Acids Research Articles

Electrochemical investigations of the effect of N-substituted aminosulfonic acids with a piperazinic ring pH buffers on heavy metal processes which may have implications on speciation studies

The influence of piperazine- N, N′-bis(2-ethanesulfonic acid) (PIPES), N-2-hydroxyethylpiperazine- N′-2-ethanesulfonic acid (HEPES) and N-hydroxyethylpiperazine- N′-2-hydroxypropanesulfonic acid (HEPPSO) on the redox processes of cadmium, lead and zinc was investigated by differential pulse anodic stripping voltammetry (DPASV) and differential pulse polarography (DPP) (only for lead). The studies showed that these pH buffers did neither complex cadmium and zinc nor modify to a significant extent the reversibility of the heavy metals electrochemical DPASV and DPP responses, under the experimental conditions used, indicating that the three buffers might be suitable for speciation studies of those metal ions. Depression of lead peak current, recorded by DPASV and DPP, in the presence of all the pH buffers was observed due to surface coverage of the electrode by those compounds, which was confirmed by alternating current voltammetry (ACV). A slight complexation was also verified for lead–PIPES and lead–HEPES systems, this phenomenon being more marked for lead–HEPPSO system (log βPb–HEPPSO=2.56±0.06 ( n=5), determined by potentiometric titrations (pH measurements)). These results indicate that these pH buffers are not suitable for lead speciation studies, unless the extent of its complexation by the buffer is considered.

Synthesis of mono- and bis(aminomethyl)dioxanes fromN-[3-(2-chloroethoxy)-2-hydroxypropyl]sulfamates

N-Substituted aminomethyl- and 2,5-bis(aminomethyl)-1,4-dioxanes were prepared by cyclization of the corresponding potassiumN-[3-(2-chloroethoxy)-2-hydroxypropyl]sulfamates under the action of an alkaline agent followed by alcoholysis of the resulting sulfamic acids.

Influence ofN-Substituted Aminosulfonic Acids with a Morpholinic Ring pH Buffers on the Redox Processes of Copper or Zinc Ions: A Contribution to Speciation Studies

The electrochemical behavior of copper(II) or zinc(II) metal ions was investigated in the presence of different pH buffers [3-(N-morpholino)-2-hydroxypropanesulfonic acid (MOPSO), 2-(N-morpholino)ethanesulfonic acid (MES) and 3-(N-morpholino)propanesulfonic acid (MOPS)] by differential pulse anodic stripping voltammetry (DPASV) and differential pulse polarography (DPP). These studies showed that these pH buffers did not complex zinc or copper, but MOPSO and MOPS modified the reversibility of copper electrochemical DPASV and DPP (only MOPSO) responses, under the experimental conditions used. Depression of peak current for both metal ions was also observed in the presence of all pH buffers due to surface coverage of the electrode by those compounds, which was verified by alternating current voltammetry (ACV).

Influence of N-Substituted Aminosulfonic Acids with a Morpholinic Ring pH Buffers on the Redox Processes of Copper or Zinc Ions: A Contribution to Speciation Studies

Influence of N-Substituted Aminosulfonic Acids with a Morpholinic Ring pH Buffers on the Redox Processes of Copper or Zinc Ions: A Contribution to Speciation Studies

The identification of unusual bile acid metabolites by tandem mass spectrometry: use of low-energy collision-induced dissociation to produce informative spectra.

The use of collision-induced dissociation (CID) tandem mass spectrometry (MS/MS) has been shown to produce fragmentation that is useful for the structural analysis of bile acids and their conjugates. Low-energy CID using a triple quadrupole has been used to help characterise bile acid identity but the majority of work has been conducted using high-energy CID on specialised instrumentation. This paper describes the use of low-energy CID as a rapid method for identification of urinary bile acids and presents some examples of its use in the diagnosis of liver disease in infants. These include the differential diagnosis of peroxisomal disorders, identification of compounds (e.g. 3 beta,7 alpha-dihydroxy-5-cholenoic acid 3-sulphate) indicative of 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase deficiency and the confirmation of the identity of an unusual bile acid series consisting of different conjugates of lithocholic acid. The use of lithium cationisation and derivatisation with aminosulfonic acids for the analysis of unconjugated and glycine-conjugated bile acids has also been evaluated.

Fundamental Studies of the Effects of Photo-additive Structure on Resist Outgassing.

The effect of different photoadditives in high and low activation energy resist resins on resist outgassing during lithographic exposure was studied by quartz microbalance and gas chromatography/mass spectroscopy techniques. The resist outgassing was analyzed both qualitatively and quantitatively and structure-property relationships were developed between resist outgassing and the molecular structure of photoacid generators (PAG) and other additives. The photoadditives examined included, aryl iodonium perfluoroalkylsulfonates, triarylsulfonium perfluoroakylsulfonates, photogenerators of sulfamic acids, 2-nitrobenzyl PAG's and doxyl derivatives. It was found that during exposure sulfonium salt formulated resists gave a lower outgassing of aromatic compounds than iodonium salt formulated resists while a formulation with a nitrobenzyl PAG did not show any aromatic materials outgassing. The use of a stable free radical additive, methyl 5-doxyl stearate, in a resist formulated with an iodonium salt was found to also dramatically reduce outgassing of aromatic compounds probably through termination of triplet state radical photoproducts. Sweet PAG resist formulations were found to have greatly decreased outgassing during exposure originating from the cleavage of low activation energy acetal protecting groups.

Electrochemical study of proton ionisation, copper(II) complexation and surfactant properties of piperazine- N- N′-bis[2-hydroxypropanesulfonic acid] pH buffer : Comparison with other N-substituted aminosulfonic acids pH buffers

The surface active behaviour of the piperazine- N- N′-bis[2-hydroxypropanesulfonic acid] (POPSO) and its capability to bind copper(II) were investigated at 25°C and 0.5 mol l −1 ionic strength. For acid dissociation and copper(II)–buffer complexation determinations, ion selective electrode potentiometric titration data (pH or pH plus pCu measurements) were evaluated with the help of SUPERQUAD computational program. The buffer concentration influenced markedly the results. At 10 mmol l −1 buffer, p K a1=7.69 and p K a2=8.20 were obtained. At 2.0 mmol l −1, p K a2=7.92 and insolubility of the buffer at pH≤7.0 prevented the determination of p K a1. Too low buffer power of the solution prevented the determination of the p K a2 value at 0.8 mmol l −1. At that POPSO concentration, the following Cu(II)–POPSO stability constants (log β ab , corresponding to the equilibrium: aCu 2++ bL 2−↔[M a L b ] 2 a−2 b ; H 2L=POPSO) were obtained: β 11=4.1, β 12=8.1, β 13=12, β 14=16, β 15=19, β 16=23. The values of β ab (and the statistical quality of the fit) decreased when the buffer concentration increased (e.g., log β 13=9.6 at 10 mmol l −1 POPSO). Aggregation of molecules of POPSO may be the cause of this behaviour. Demonstration of a marked surface active behaviour of 10 mmol l −1 POPSO solution was obtained by alternating current polarography. A conditional stability constant of Cu(II)–buffer at 10 mmol l −1 POPSO concentration and pH=8.0, was also determined by the Scatchard method: log K=5.7 (|Cu(II)| bound/|buffer| total: 0.088–0.19). The POPSO properties are compared with those of other similar zwitterionic compounds previously studied by us: N-[2-hydroxyethyl]piperazine- N′-[2-ethanesulfonic acid] (HEPES), N-[2-hydroxyethyl]piperazine- N′-[2-hydroxypropanesulfonic acid] (HEPPSO), 3-[ N, N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO) and piperazine- N, N′-bis[2-ethanesulfonic acid] (PIPES).

Synthesis of Chiral Vinylogous Sulfonamidopeptides (vs-Peptides)

Chiral vinylogous amino sulfonic acids (vs-amino acids) were synthesized starting from either L- or D-α-amino acids via N-Boc–α-amino aldehydes. Wittig-Horner reaction with methyl (or ethyl) diethylphosphoryl methanesulfonate and nBuLi gave the corresponding α,β-unsaturated sulfonates in high yield and complete (E) stereoselectivity. Cleavage of the methyl (ethyl) ester was effected by treatment of the sulfonates with nBu4NI in refluxing acetone. Treatment of the nBu4N+ sulfonate salts with SO2Cl2-PPh3-CH2Cl2gave the corresponding sulfonyl chlorides as stable chromato-graphable compounds. The synthetic sequence proved successful not only starting from α-amino acids carrying unfunctionalized side-chains (Ala, Val, Phe, Leu, Pro), but also with functionalized α-amino acids (Ser, Tyr, Gln) provided that the side chains were suitably protected. The sulfonyl chlorides were coupled with the amine salts to give vs-dipeptides. Amine hydrochlorides were prepared from N-Boc derivatives by treatment with HCl in methanol or ethyl acetate. The process was further iterated to give vs-tripeptides and vs-tetrapeptides. The above procedure was also used to synthesize “mixed” peptides, which incorporate both proteinogenic α-amino acids and vs-amino acids. Proteinogenic α-amino acids were incorporated at both the C-terminal and the N-terminal position.

Synthesis of Chiral Vinylogous Sulfonamidopeptides (vs-Peptides)

Chiral vinylogous amino sulfonic acids (vs-amino acids) were synthesized starting from either L- or D-α-amino acids via N-Boc–α-amino aldehydes. Wittig-Horner reaction with methyl (or ethyl) diethylphosphoryl methanesulfonate and nBuLi gave the corresponding α,β-unsaturated sulfonates in high yield and complete (E) stereoselectivity. Cleavage of the methyl (ethyl) ester was effected by treatment of the sulfonates with nBu4NI in refluxing acetone. Treatment of the nBu4N+ sulfonate salts with SO2Cl2-PPh3-CH2Cl2gave the corresponding sulfonyl chlorides as stable chromato-graphable compounds. The synthetic sequence proved successful not only starting from α-amino acids carrying unfunctionalized side-chains (Ala, Val, Phe, Leu, Pro), but also with functionalized α-amino acids (Ser, Tyr, Gln) provided that the side chains were suitably protected. The sulfonyl chlorides were coupled with the amine salts to give vs-dipeptides. Amine hydrochlorides were prepared from N-Boc derivatives by treatment with HCl in methanol or ethyl acetate. The process was further iterated to give vs-tripeptides and vs-tetrapeptides. The above procedure was also used to synthesize “mixed” peptides, which incorporate both proteinogenic α-amino acids and vs-amino acids. Proteinogenic α-amino acids were incorporated at both the C-terminal and the N-terminal position.

Photogenerators of Sulfamic Acids; Use in Chemically Amplified Single Layer Resists.

A novel material, bis(4-t-butylphenyl)iodonium cyclamate, an alkylaminosulfonate salt capable of photogenerating a zwitterion sulfamic acid is shown to have utility in 248 and 193nm single layer chemically amplified resists. Specifically, bis(4-t-butylphenyl)iodonium cyclamate may be employed as a self-leveled photoacid generator (PAG) in resists in which protecting groups with a low activation energy are present. Alternatively, in resins protected with high activation groups, this material serves the role of a low volatility, low diffusion photodecomposable base used in conjunction with a super-acid PAG. In both types of resists, bis(4-t-butylphenyl)iodomum cyclamate reduces resist line slimming and T-topping by respectively reducing acid diffusion and its depletion at the resist surface. The above mentioned advantages of reduced line slimming and post-exposure bake delay (PED) stability are accomplished both in the case of the low and high activation energy resists without the need for an additional amine component. Finally, formulation of the low activation energy resist with the cyclamate PAG suppresses film thickness loss during exposure thus reducing outgassing off volatiles.

Conformational Studies of Chiral Vinylogous Sulfonamidopeptides

AbstractThe conformational preferences of chiral vinylogous aminosulfonic acids (vs‐amino acids) and of the corresponding oligomers (vs‐peptides) were investigated by a combination of X‐ray crystallography, variable‐temperature (VT) 1H NMR spectroscopy, FT‐IR spectroscopy, and NOE experiments. The major source of conformational freedom in the monomers is the rotation around the CC bond connecting the double bond with the allylic stereocenter (NC*CC). The allylic conformational preferences can be altered in the oligomers by the formation of secondary structures enforced by hydrogen bonding. Twelve‐membered‐ring hydrogen bonding is detected in the crystal structure of vs‐dipeptide 9, while fourteen‐membered‐ring hydrogen bonding is the most common folding pattern for the oligomers in chloroform solution. The experimental results are complemented by computer modeling: suitable force‐field (FF) parameters for the unsaturated sulfonamide group were developed from ab initio calculations. A Goodman–Still systematic pseudo‐Monte‐Carlo search was used for the conformational search. The conformers were minimized in chloroform with the GB/SA model. The calculations correctly predicted both the size of the hydrogen‐bonded ring and its relative importance, in agreement with the experimental data in solution.

Synthesis of Sulfonamido‐Pseudopeptides: New Chiral Unnatural Oligomers

Chiral vinylogous aminosulfonic acids 1 can be used to synthesize the title compounds 2 by a straightforward iterative approach. The new chiral unnatural oligomers have defined conformational preferences in chloroform and may have interesting recognition and biological properties.

Standard enthalpies of formation in the crystalline state of aminomethanesulfonic acid, 2-aminoethanesulfonic acid, and the three aminobenzenesulfonic acids

The standard ( p o = 0.1 MPa) molar enthalpies of formation of some crystalline aminosulfonic acids were determined at the temperature 298.15 K by rotating-bomb calorimetry. [[formula]] The difference between Δ f H o m(cr) for an NH 2RSO 3H and the corresponding NH 2RCO 2H has been found to be constant: -(198 ± 2) kJ·mol -1.

The reaction of sulfamic acid derivatives with epoxides

Reactions of diglycidyl and allylglycidyl ethers with salts of sulfamic acid followed by acidic hydrolysis of the products afforded the corresponding aminoethers. The alcoholysis of sulfamic acids with ethanol was suggested as a method for mild elimination of the sulfo group.

X-ray diffraction study of N-substituted sulfamic acids I. Molecular and crystalline structure of N-methylsulfamic acid and potassium N-methylsulfamate

X-ray diffraction study of N-substituted sulfamic acids I. Molecular and crystalline structure of N-methylsulfamic acid and potassium N-methylsulfamate

Nitroimidazoles, XIV: Synthesis of 4-nitroimidazoles with 1-substituents containing acid, ester or phenol functions, and radiosensitizing efficiency of some of these compounds.

1,4-Dinitroimidazole and 1,4-dinitro-2-methylimidazole were reacted with aminocarboxylic acids and their esters, aminosulfonic acids, and aminophenol to obtain the corresponding 1-substituted-4-nitroimidazoles. The radiosensitizing efficiency of some esters of 2-(4-nitro-1-imidazolyl)alkanecarboxylic acids was tested.

Investigation of the Interaction of Sodium Chloride and Two Amino Sulfonic Acids, HEPES and MOPSO, by EMF Measurements.

Ionic interactions in the two systems NaCl-HEPES (N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid) and NaCl-MOPSO (3-(N-Morpholino)-2-hydroxypropanesulfonic acid) have been studied in terms of their mutual influence on the respective activity coefficients of each component. Activity coefficients for each component of the two systems and for corresponding buffers are calculated from emf measurements of solutions containing NaCl, the aminosulfonic acid, and its conjugate base in a NalSE/solution/AgCl-Ag cell at 5, 15, 25, and 37 °C.

Single column ion chromatography of ammonium ion, alkali metals and alkyl amines

Comparative efficiencies of oxalic, dichloroacetic and sulfamic acids as eluents in ion chromatographic determination of ammonium ion, alkali ions and alkyl amines have been evaluated. In all cases these eluents compared favorably to the popular nitric acid eluent employed for the ion chromatography of these species. Sulfamic acid has been found to be particularly superior for the separation and quantitation of alkali ions and several alkyl amines in ppm and sub ppm range.

ACIDES α ET β AMIDINO SULFONIQUES

Abstract The title compounds (4 or 11, Table) are synthesized by coupling, in an aqueous basic medium, of the α or β amino sulfonic acids with thioiminoethers salts or cyanamide (Fig. 4).

13C NMR studies on the structure of aminosulfonic acids in dimethyl sulfoxide and water

AbstractThe 13C NMR spectra of three aminosulfonic acids (HA) [p‐aminobenzenesulfonic acid (sulfanilic acid), amino‐methanesulfonic acid and 2‐aminoethanesulfonic acid (taurine)] and their anions (A−) and cations (H2A+) were obtained using aqueous H2SO4, fuming H2SO4 and Me2SO solutions of trifluoromethanesulfonic acid. The chemical shifts of HA, A− and H2A+ and the protonation and deprotonation shifts of HA are compared with corresponding data for related amines and sulfonic acids in Me2SO and water. Our results indicate that the three aminosulfonic acids are essentially zwitterionic in Me2SO.