Influence of Ionic Strength and Cation Nature on the Deprotonation of Methanediol in Alkaline Solution†

Norkus, Eugenijus; Pauliukaitė, Rasa; Vaškelis, Algirdas; Butkus, Eugenijus; Jusys, Z.; Kreneviciene, Marija

doi:10.1039/a706993f

Cited by 16 publications

(7 citation statements)

References 14 publications

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“…The fact that no formaldehyde is observed by experimental results is mainly due to the participation of hydroxide in stage I followed by a fast gem ‐diolate dehydrogenation of stage II. Methanediol is a weak acid, for which the p K a is around 13 17. Thus gem ‐diolate could react with water to form the neutral methanediol and release OH – again.…”

Section: Resultsmentioning

confidence: 99%

The Nature of Hydrogen Production from Aqueous‐Phase Methanol Dehydrogenation with Ruthenium Pincer Complexes Under Mild Conditions

Lei

Pan

2015

Eur J Inorg Chem

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A density functional theory (DFT) study was performed to unveil the nature of dihydrogen (H 2 ) production from aqueous-phase methanol dehydrogenation catalyzed by a ruthenium pincer complex. Three catalytic cycles of methanol, formaldehyde, and formate dehydrogenations were investigated at the ωB97X-D/BSI level. The calculated results indicate that the methanol-assisted hydrogen-release step is much more favorable than the direct hydrogen-release one. The dehydrogenation step, the methanol-assisted hydrogenrelease step, and the CO 2 -release step are the rate-determining steps of methanol, formaldehyde, and formate dehydro- [a] State Key

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Section: Resultsmentioning

confidence: 99%

The Nature of Hydrogen Production from Aqueous‐Phase Methanol Dehydrogenation with Ruthenium Pincer Complexes Under Mild Conditions

Lei

Pan

2015

Eur J Inorg Chem

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“…Another possible source of chemical exchange could be due to deprotonation of hydroxy groups in glycols. The degree of deprotonation is expected to increase with increasing carbonate concentration as pH increases (Table ), but because the p K a for MG is ∼13.5, at the higher carbonate concentration used here (where the pH is around 10.5), only 0.1% of the total amount of MG is expected to be deprotonated, and the proton exchange is likely to be very fast, resulting in no peak broadening.…”

Section: Resultsmentioning

confidence: 98%

Molecular Speciation and Mesoscale Clustering in Formaldehyde–Methanol–Water Solutions in the Presence of Sodium Carbonate

2013

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Nanoporous organic gels can be synthesized from aqueous solutions of formaldehyde and resorcinol in the presence of basic electrolytes such as sodium carbonate. It is well known that formaldehyde is present in the form of methylene glycols or methoxy-glycols in aqueous and methanolic solutions, but influence of pH or electrolytes on speciation in these solutions has not been previously studied. Here we investigated effects of sodium carbonate on the speciation and colloidal scale clustering in formaldehyde-methanol-water solutions in the absence of resorcinol. We used (13)C NMR spectroscopy to quantitatively characterize molecular speciation in solutions and to estimate corresponding equilibrium constants for glycol dimerization and methoxylation. We found that species distribution is essentially independent of carbonate concentration for pH values between 3.4 (no carbonate) and 10.6. This was also consistent with ATR IR measurements of the same solutions. However, NMR spin-spin relaxation time measurements showed an unexpected behavior for glycols and especially for diglycol (but not for methanol), with relaxation times strongly decreasing with increasing carbonate concentration, indicating differences in local molecular environment of glycols. We further used dynamic light scattering to confirm the presence of mesoscale clustering in formaldehyde-methanol-water (for both H2O and D2O) solutions in the presence of sodium carbonate. We propose that the observed phenomena are due to glycol-rich cluster mesospecies in equilibrium bulk solution, together forming a thermodynamically stable mesostructured liquid phase.

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“…In addition, it is also an eco-friendly agent due to the ease of effluent treatment and less toxicity. Norcus et al have already investigated the CuSa (OH) 3 2-complex as the principal electro active species in the catalytic reaction 10 . Still it is necessary to understand the influence of process parameters on the film quality for desired application.…”

Section: Research Articlementioning

confidence: 99%

Electroless Copper Deposition Using Saccharose Containing Copper Methane Sulphonate Bath with Thiourea as Stabilizer

2014

Chem Sci Trans

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Electroless copper deposition is used in the fabrication of integrated circuit (IC) interconnections, micro-electro-mechanical systems (MEMS) devices and printed circuit board (PCBs). In order to meet the long term usage of chemical bath for electroless deposition, an ecofriendly copper methane sulphonate (CuMS) was used to prepare the chemical bath for Cu deposit. The deposition parameters such as temperature, pH, Cu ion concentration and para-formaldehyde concentration were optimized at 28 °C with 3 g/L of CuMS, 10 g/L of para-formaldehyde for the pH of 12.75.The deposition rate was increased for high concentration of Cu and para-formaldehyde in the chemical bath. Highly stable bath was achieved at 28 °C with 1 ppm thiourea content and produced uniform Cu film surface with larger grains. Good quality and (200) oriented Cu thin film with larger crystallite size was observed with 1 ppm thiourea added bath.

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Influence of Ionic Strength and Cation Nature on the Deprotonation of Methanediol in Alkaline Solution†

Abstract: The pK a values of methanediol deprotonation were found to decrease with increase in solution ionic strength as estimated by a 13 C NMR titration method.

Cited by 16 publications

References 14 publications

The Nature of Hydrogen Production from Aqueous‐Phase Methanol Dehydrogenation with Ruthenium Pincer Complexes Under Mild Conditions

The Nature of Hydrogen Production from Aqueous‐Phase Methanol Dehydrogenation with Ruthenium Pincer Complexes Under Mild Conditions

Molecular Speciation and Mesoscale Clustering in Formaldehyde–Methanol–Water Solutions in the Presence of Sodium Carbonate

Electroless Copper Deposition Using Saccharose Containing Copper Methane Sulphonate Bath with Thiourea as Stabilizer

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