Jean-François Gal

Université Côte d'Azur · Institut de Chimie de Nice

In this review, the principles of gas-phase proton basicity measurements and theoretical calculations are recalled as a reminder of how the basicity PA/GB scale, based on Brønsted–Lowry theory, was constructed in the gas-phase (PA—proton affinity and/or GB—gas-phase basicity in the enthalpy and Gibbs energy scale, respectively). The origins of exce...

Alkyl carbonates are essential components in the manufacture of lithium-ion batteries, as electrolytes or additives. The Lewis basicity of alkyl carbonates and other carbonyl compounds used in electrochemistry are often characterized by their Donor Number (DN). Assessment of the literature DN values displays great discrepancies. This is attributed...

This work extends our earlier quantum chemical studies on the gas-phase basicity of very strong N-bases to two series of nitriles containing the methylenecyclopropene and cyclopropenimine scaffolds with dissymmetrical substitution by one or two electron-donating substituents such as Me, NR2, N=C (NR2)2, and N=P (NR2)3, the last three being strong d...

This Glossary contains definitions, explanatory notes, and sources for terms used in physical organic chemistry. Its aim is to provide guidance on the terminology of physical organic chemistry, with a view to achieving a consensus on the meaning and applicability of useful terms and the abandonment of unsatisfactory ones. Owing to the substantial p...

Metal triflates have shown a large variety of possibilities as catalysts in organic reactions. Some selected examples of their catalytic activity, in particular in C−O and C−C bond formation are presented. A better understanding of the mode of interaction between these Lewis acids and organic functional groups as ligands should allow for an easier...

The cover picture shows the Institut de Chimie de Nice (ICN), the chemistry research laboratory of the Université Côte d'Azur and the CNRS, which is located in the Parc Valrose in Nice, France. One‐hundred chemists work at the ICN, and are organized in four research teams: aroma, biomedical, radio‐, and material chemistry. This Editorial summarizes...

The ‘Institut de Chimie de Nice’ (ICN), founded in 2012, celebrates its 10th anniversary in 2022. Today, the ICN is part of the University Côte d'Azur (UCA), one out of nine excellence universities in France. ICN is also affiliated to the CNRS. We use the institute's anniversary to reflect on the origins and the successful evolution of research in...

The Lewis basicity of selected organic bases, modeled by the enthalpies of adduct formation between gaseous BF3 and bases in dichloromethane (DCM) solution, is critically examined. Although experimental enthalpies for a large number of molecules have been reported in the literature, it may be desirable to estimate missing or uncertain data for impo...

The Lewis basicity of selected organic bases, modeled by the enthalpies of adduct formation between gaseous BF3 and the bases in dichloromethane (DCM) solution, is critically examined. Although experimental enthalpies for a large number of molecules have been reported in the literature, it may be desirable to estimate missing or uncertain data for...

The Lewis basicity of selected organic bases, modeled by the enthalpies of adduct formation between gaseous BF3 and the bases in dichloromethane (DCM) solution, is critically examined. Although experimental enthalpies for a large number of molecules have been reported in the literature, it may be desirable to estimate missing or uncertain data for...

The gas-phase basicity of nitriles can be enhanced by a push–pull effect. The role of the intercalated scaffold between the pushing group (electron-donor) and the pulling (electron-acceptor) nitrile group is crucial in the basicity enhancement, simultaneously having a transmission function and an intrinsic contribution to the basicity. In this stud...

New organometallic superacids of sulfonic acid derivatives were designed on the basis of acidity enhancement by internal bonding with an electron-pair acceptor group BX2 (X = H, F, Cl, Br). The acidity enhancement in the gas phase was assessed using the B3LYP/6-311++G(d,p) method. Two classes of superacids were devised. The first series was based o...

Important changes were recently made to the International System of Units. The readers involved in chemistry and physics, either teachers or advanced students, should be aware of the new definitions of the kilogram, the mole, and more generally of the changes in International System of Units (SI, “Système International”) recently approved at the 26...

Background The ubiquitous Lewis acid/base interactions are important in solution processes. Analytical chemistry may benefit of a better understanding of the role of Lewis basicity, at the molecular level or acting through a bulk solvent effect. Objective To clearly delineate (i) the basicity at a molecular level, hereafter referred as solute basi...

Data on the gas-phase energetics of anion/cation interactions are relatively scarce. In this work, gas-phase alkali metal cation basicity (AMCB) scales were established for a series of 15 benzoate ions XC6H4COO- with Li+, Na+, K+, Rb+ and Cs+ on the basis of mass spectrometry experiments and high-level calculations. A wide range of electron-donatin...

Quantum chemical calculations were carried out for deprotonated (P−) and protonated purine (PH+) and for adducts with one alkali metal cation (P−M+ and PM+, where M+ is Li+ or Na+) in the gas phase {B3LYP/6-311+G(d,p)}, a model of perfectly apolar environment, and for selected structures in aqueous solution {PCM(water)//B3LYP/6-311+G(d,p)}, a refer...

The Lewis basicity of a series of phosphoryl compounds was examined using DFT and ab initio methods, including solvation effects. The enthalpies of adduct formation with two archetypal Lewis acids, antimony pentachloride and boron trifluoride, used to define the donor number DN and the BF3 affinity (BF3A) respectively, were examined. The BF3 adduct...

Interactions of cycloheptatriene derivatives, C7H6X, (X = NH, PH, AsH, O, S, Se) with the cations H⁺, CH3⁺, Cu⁺, Al⁺, Li⁺, Na⁺, and K⁺ are studied using B3LYP functional and 6-311++G(d,p) basis set. The calculated gas-phase cation affinities (CA) and cation basicities (CB) for all molecules decrease as H⁺ > CH3⁺ > Cu⁺ > Al⁺ > Li⁺ > Na⁺ > K⁺. We use...

Compounds containing biguanide moiety, such as buformin, phenformin, and metformin are well recognized for their antihyperglycaemic action. Imeglimin is a dihydro-1,3,5-triazine that can be considered as a cyclic metformin derivative, which has been tested as a promising new antidiabetic drug. Quantum-chemical calculations have been carried out to...

Energy dispersive X-ray spectrometry (EDX or EDS) is a technique often implemented on scanning electron microscopes, and a regularly used method for qualitative characterization for solid catalysts. This technical note reports a method for the determination of the metal content in a sulfonated polyether ether ketone (SPEEK) in the form of indium(II...

Interaction of H2O, H2S, H2Se, NH3, PH3, and AsH3 with cations H⁺, CH3⁺, Cu⁺, Al⁺, Li⁺, Na⁺, and K⁺ was studied from the energetic and structural viewpoint using B3LYP/6-311++G(d,p) method. The charge transfer from the Lewis bases to the cations reduces lone pair/lone pair (LP/LP) repulsion in H2O, H2S, and H2Se and LP/bond pair (LP/BP) repulsion i...

Sulfonated PolyEtherEtherKetone (SPEEK) in the form of indium(III) salt was tested as solid, recyclable catalyst. The In(III) content and the number of sulfonate groups coordinated to In3+ was determined using energy dispersive X-ray spectrometry (EDX/EDS).

Substituted biguanides are known for their biological effect and a few of them are used as drugs, the most prominent example being metformin (1,1-dimethylbiguanide, IUPAC name: N,N-dimethylimidodicarbonimidic diamide). Owing to the presence of hydrogen atoms at the amino groups, biguanides exhibit a multiple tautomerism. This aspect of their struct...

Relationship between the C═O–X⁺ (X = H, Li, Na, K, Al, Cu) angle and covalent characteristic of the X⁺–M (M = CH2O, CH3CHO, acetone, imidazol-2-one (C2H2N2O), cytosine, γ-butyrolactone) was investigated, theoretically. The calculated electron densities ρ at the bond critical points revealed that the covalency of the M–X⁺ interaction depended on the...

The guanylated bioamine agmatine, , formed by decarboxylation of the proteinogenic amino acid arginine, plays an important role in the physiological processes of living organisms. Its structure is marked by the flexibility of the four-carbon chain connecting the two potentially basic amino and guanidino sites. Owing to these noteworthy properties a...

In an article dedicated to the structure and energetics of the adduct Ag⁺/[6]helicene (Chem. Phys. Letters 633 (2015) 105-108), the authors measured an energy threshold for the dissociation into Ag⁰ and ([6]helicene)+•, using collision induced dissociation in an ion trap mass spectrometer. The result is incorrectly interpreted in term of a bond dis...

Owing to the importance of metal triflates in catalysis, the affinity of the cationic center for a selection of organic ligands was explored for In(III) and Zn(II) triflates. The organic Lewis bases include a variety of carbonyls (amides, unsaturated ketones, a lactone) and cyclic 1,2-diols. The relative affinity of the ligands for the cationic cen...

Metal triflates, often called Lewis superacids, are potent catalysts for organic synthesis. However, the reactivity of a given Lewis superacid toward a given base is difficult to anticipate. A systematic screening of catalysts is often necessary when developing synthetic methodologies. Presented herein is the development of quantitative reactivity...

The effect of number of CH3 groups (n) on the cation (H+, Li+, Na+, Al+, CH3+) affinity, polarizability, and dipole moment of 14 simple molecules was investigated. Linear correlations were observed between the polarizabilities and the number of methyl groups. The variations of the cation affinities and dipole moments with the number of methyl group...

Nitrogen bases containing one or more pushing amino-group(s) directly linked to a pulling cyano, imino, or phosphoimino group, as well as those in which the pushing and pulling moieties are separated by a conjugated spacer (C═X)n, where X is CH or N, display an exceptionally strong basicity. The n-π conjugation between the pushing and pulling group...

A large number of experimental and computational gas-phase basicity data for monocyclic and polycyclic aromatic azines, including values taken from the recent literature, were examined to explore how internal (structural) effects influence gas-phase basicity (GB) and/or proton affinity (PA) of aza nitrogen. Substituent electron withdrawing effects...

This chapter focuses on the thermo-dynamic approach of the Lewis basicity. Owing to the generality of the definition of Lewis acids and bases, there is no single reference acid for defining a unique Lewis basicity scale. Most thermodynamic data used for the definition of affinity-basicity scales pertain to a simple 1:1 Lewis acid/base association o...

The experimental aspects of the determination of thermochemical data for the attachment of the aluminum monocation Al(+) to neutral atoms and molecules are reviewed. Literature aluminum cation affinities (enthalpy scale) and basicities (Gibbs energy scale) are tabulated and discussed. Ab initio quantum chemical calculations at the G4 level on 43 ad...

The ene-process with unsaturated ketones was catalyzed by Lewis acids such as bismuth or indium triflates. Unlike aldehydes, the reverse ene-process occurs with ketones, resulting in incomplete conversions, as shown by control experiments and analysis by ESI-MS.

DFT calculations have been performed for a series of push-pull nitriles [(R2N)n(X=Y)iCN, where i = 0, 1, or 2, n = 1, 2, or 3, R2N = H2N, Me2N, or C4H8N]. The possible protonation N-sites (N-cyano, N-imino, and N-amino) have been examined and their proton affinities (PA) estimated. For all compounds in the series, even for those containing the guan...

The mechanism of the CuAAC reaction has been investigated by electrospray ionization mass spectrometry (ESI-MS) using a combination of the neutral reactant approach and the ion-tagging strategy. Under these conditions, for the first time, putative dinuclear copper intermediates were fished out and characterized by ESI(+)-MS/MS. New insight into the...

Effects of the pushing groups (electron donors) for nitriles increase as follows: H2N < H2N-N=N < H2N-CH=CH < H2N-CH=N < (H2N)(2)C=CH < (H2N)(2)C=N < (H2N)(3)P=N. The G2(MP2)-calculated PA(N-cyano) for (H2N)(2)C=N-C equivalent to N and (H2N)(3)P=N-C equivalent to N are larger than that of HC equivalent to N by 186 and 250 kJ mol(-1), respectively....

The mechanism of the CuAAC reaction has been investigated by electrospray ionization mass spectrometry (ESI‐MS) using a combination of the neutral reactant approach and the ion‐tagging strategy. Under these conditions, for the first time, putative dinuclear copper intermediates were fished out and characterized by ESI(+)‐MS/MS. New insight into the...

The mechanisms of the Ugi and Ugi–Smiles reactions were investigated by using finely selected reaction conditions that allowed all of the intermediates to be “fish-out” and characterized by ESI-MS/MS. New insight into the Ugi and Ugi–Smiles reaction mechanisms is provided without using charge-tagged reagents. Characterization of the isomeric specie...

The cover picture shows the plume of ions created in the ESI source of a mass spectrometer while sampling the key intermediate of the Ugi four-component reaction (U-4CR). In particular ESI-MS has been employed to disperse the fog on the mechanisms of the Ugi and Ugi–Smiles reactions by intercepting and characterizing unstable, non-isolable intermed...

According to high level calculations, the upper part of the previously published FT-ICR lithium cation basicity (LiCB at 373 K) scale appeared to be biased by a systematic downward shift. The purpose of this work was to determine the source of this systematic difference. New experimental LiCB values at 373 K have been measured for 31 ligands by pro...

The effect of Cs(+) ligation on the decarboxylation of malonic acids (unsubstituted and methyl-, dimethyl-, ethyl-, and phenyl-substituted) in their carboxylate form was studied in the gas phase using tandem mass spectrometry. The study is based on the comparison of the decarboxylation of the bare monoanion (hydrogen malonates) and of the cesium ad...

The concept of donor number (DN), based on calorimetric measurements of adduct formation between Lewis bases and a reference Lewis acid, proved to be fruitful for the interpretation of various medium effects, and, more generally, for the understanding of Lewis basicity. Attempts to extend the DN scale (a thermodynamic basicity scale) using indirect...

The interaction between the cesium cation and fulvic or humic acids is supposed to play a role in cesium mobility in the environment, which is of importance in the context of geographical dispersion or concentration of the corresponding radionuclides. Among the singly charged positive clusters generated by electrospray ionization of mixtures of car...

Measuring the relative sensitivity factors (Sr) in Bayard-Alpert ion gauge is technically demanding and time-consuming. Moreover, the accuracy deterioration in the low pressure range (high vacuum) becomes problematic. Experimental Sr values are reported for 91 molecules of diverse molecular structures. A three-descriptor QSPR model based on experim...

Metal salts of triflic acid, CF3SO2OH and of triflimidic acid, [CF3SO2]2NH, often called “Lewis superacids”, are powerful catalysts for several classes of reactions. Typical applications developed at the Institut de Chimie de Nice during the last decade, mostly in the domain of inter‐ and intramolecular carbon–carbon, carbon–oxygen and carbon–sulfu...

The determination of the gas-phase basicity of organic bases (ligands) toward the lithium cation may be achieved by mass spectrometry, as described for protonic gas-phase basicity by Sunderlin et al. (J. Chem. Educ. 2005, 82, 1071-1073). The lithium cation-bound dimers, generated by electrospray ionization, are dissociated by collision-induced diss...

The interaction between two Lewis "superacid" catalysts Zn(OTf)(2) and In(OTf)(3) and series of amide and phosphate ligands is quantitatively characterized by electrospray ionization mass spectrometry (ESI-MS). A specific feature of the ESI-MS spectra of the mixture of metal triflates and Lewis bases is the formation of ionic adducts resulting from...

The impossibility of establishing a universal scale of Lewis basicity does not prevent the determination of the quantitative behavior of Lewis bases, thanks to scales constructed against particular Lewis acids: BF3, 4-FC6H4OH, I2, Li+, Na+, K+, Al+, Mn+, CpNi+, and CH3NH3+. These scales encompass important types of bonds formed in a Lewis acid–base...

The equimolecular adducts between aminoalkoxyphosphines (Me 2 N) 3–n (tBuO) n P with n = 1,2, and 3) and borane BH 3 have been prepared and characterised. The nmr study has been undertaken to compare some parameters ( ¹ J BH , ¹ J BP , δ ¹¹ B etc.) with both those derived from the enthalpies of reaction of diborane with the parent phosphines and fr...

In a series of 4-substituted camphors, in which the substituent, X, varies from ethyl through hydrogen to nitro, we have shown that the enthalpies of complexation, with BF3 in dichloromethane, which cover a range of 14.5 kJ mol-1 correlate well with r > 0.99 with polar substituent constants with the sensitivity ρ* ca. 8. IR spectroscopy of the free...

The relative Lewis basicity of a series of phosphoryl compounds toward cations M(n+)(OTf)(n-1) derived from triflate salts, M(OTf)(n), is ranked using electrospray mass spectrometry according to competitive adduct formation.

Trifluoromethylsulfonate (triflate) and bis(trifluoromethylsulfonyl)imide (triflimide) salts, well-known Lewis acid catalysts, present some difficulty in their characterization. By using nitromethane as the solvent, useful electrospray mass spectra in positive and negative ion mode were obtained for salts of metals in oxidation states +2 and +3. In...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Systematic studies of very strong neutral acids and very strong neutral bases have been performed in the gas phase during the last decade. In the case of organic systems, the current upper limit of the basicity scale is now not very far from the current lower limit of the acidity scale. The gap between the proton affinity (PA) of the strongest orga...

Some historical notes on the activities of Teodor Lippmaa and Mikhail S. Tswett at the University of Tartu. KeywordsUniversity of Tartu-Teodor Lippmaa-Mikhail S. Tswett

The classical concept of the buttressing effect (BE) was recently redefined by us in a general way as the excess energy of a trisubstituted benzene (or another derivative) with respect to the value anticipated from pair-wise interaction energies. This new non-classical definition is applied here to methyl-substituted benzoic acids without ortho sub...

Although series of N(1), N(1)-dimethyl-N(2)-arylformamidines and of 1,1,3,3-tetraalkyl-2-arylguanidines are structurally analogous and similar electron-ionization mass spectral fragmentation may be expected, they display important differences in the favored routes of fragmentation and consequently in substituent effects on ion abundances. In the ca...

Collision-induced dissociation (CID) of the Cs+ heterodimer adducts of the nitrate anion (NO3−) and a variety of substituted benzoates (XBenz−) [(XBenz−)(Cs+)(NO3−)]− produces essentially nitrate and benzoate ions. A plot of the natural logarithm of their intensity ratio, ln[I (NO3−)/I(XBenz−)], versus the calculated cesium cation affinity (DFT B3L...

Aqueous-phase oligomer formation from methylglyoxal, a major atmospheric photooxidation product, has been investigated in a simulated cloud matrix under dark conditions. The aim of this study was to explore an additional pathway producing secondary organic aerosol (SOA) through cloud processes without participation of photochemistry during nighttim...

Calorimetric Determination of the BF3 Affinity of Pyridine by Gas/Liquid ReactionCalorimetric Determination of the BF3 Affinity of Pyridine by Liquid/Liquid ReactionDetermination by FTIR Spectrometry of the Complexation Constants of 4-Fluorophenol with Isopropyl Methyl Ketone and ProgesteroneDetermination by FTIR Spectrometry of the Complexation En...

The Lewis concept of acids and bases is discussed in every general, organic and inorganic chemistry textbook. This is usually just a descriptive treatment, as it is not possible to devise a single numerical scale suitable for all occasions. However quantitative Lewis acid-base chemistry can be developed by compiling reaction-specific basicity scale...

This work was dedicated to the characterization of the elemental composition of atmospheric particles associated with urban traffic. PM2.5 sampling campaigns were conducted in an urban road tunnel within the area of Nice: the Malraux tunnel. Samples were analyzed by ICP-MS-DRC for the determination of 16 metallic trace elements: Na, Ti, V, Mn, Fe,...

The gas-phase cesium cation affinities (CsCAs) and basicities (CsCBs) for 56 simple neutral compounds (mostly aromatic molecules) and 41 anions (carboxylates and phenolates) were calculated using density functional theory (DFT), in the context of the interaction of Cs(+) with soil organic matter (SOM). The B3LYP/def2-TZVP method gives in general Cs...

Aqueous-phase oligomer formation from methylglyoxal, a major atmospheric photooxidation product, has been investigated in a simulated cloud matrix under dark conditions. The aim of this study was to explore an additional path producing secondary organic aerosol (SOA) through cloud processes without photochemistry during night-time. Indeed, atmosphe...

Humic substances (HS), including humic and fulvic acids, play a significant role in the fate of metals in soils. The interaction of metal cations with HS occurs predominantly through the ionized (anionic) acidic functions. In the context of the effect of HS on transport of radioactive cesium isotopes in soils, a study of the interaction between the...

Relying on physicochemical knowledge, the proton cannot be spontaneously transferred from a gaseous mineral acid (HF, HCl, HBr, HI, HNO3, H2SO4, or HClO4) to a gaseous nitrogen base (NH3, alkylamine, aniline, pyridine, amidine, or guanidine). For example, the full proton-transfer from HCl to NH3, followed by the separation of Cl- and NH4+ requires...

Substituent effects on the formation of cesium cation complexes with a series of 17 benzoic acids (AH), benzoates (A^–), and the ion pairs (Cs⁺A^–) are studied by density functional theory (DFT) and mass spectrometry. This study is positioned in the context of the fate of cesium in the environment, with emphasis of th...

Fourier transform ion cyclotron resonance mass spectrometry, combined with modern ionization (fast atom bombardment , electrospray ionization, matrix-assisted laser desorption-ionization), fragmentation (collision-induced dissociation, surface-induced dissociation, one-photon ultraviolet photodissociation, infrared multiphoton dissociation, blackbo...

The gas-phase lithium cation basicities (LCBs) were obtained for histamine (HA) and its agonist 2-(β-aminoethyl)-pyridine (AEP) from collision-induced dissociation of lithium adducts using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). For measurements, MeO(CH2)2OMe, Et3PO and (Me2N)3PO (HMPA) were used as the reference co...

The gas-phase basicity and acidity of 3-hydroxy-2-propenenitrile (3-hydroxyacrylonitrile) and its sulfur-containing analogue, 3-mercapto-2-propenenitrile, have been determined by means of high-level G3B3 ab initio calculations and, in the case of the latter compound, compared with the experimental values obtained by means of FT-ICR mass spectrometr...

This review focuses on the quantitative data related to cesium cation interaction with neutral or negatively charged ligands. The techniques used for measuring the cesium cation affinity (enthalpies, CCA), and cesium cation basicities (Gibbs free energies, CCB) are briefly described. The quantum chemical calculations methods that were specifically...

An analytical methodology was developed for the determination of 21 trace elements in suspended particulate matter (PM) using a microwave digestion procedure associated with an inductively coupled plasma mass spectrometry (ICP-MS). The dynamic reaction cell (DRC) of the instrument was carefully optimized to eliminate polyatomic species causing spec...

Proton affinity (PA), lithium, sodium and potassium cation affinities (CA) in the gas phase were estimated by Gaussian-2 (G2), Möller-Plesset (MP2) methods and/or hybrid density functional theory calculations (B3LYP) for pyruvate and oxamate anions. Comparison of these affinities shows that the COO- groups of both anions have similar basicities. Di...

A combined experimental and theoretical study on the gas-phase basicity and acidity of a series of cyanovinyl derivatives is presented. The gas-phase basicities and acidities of (N[triple chemical bond]C--CH==CH--X, X=CH(3), NH(2)) were obtained by means of Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry techniques. The corresp...

A combined experimental and theoretical study on the gas-phase basicity and acidity of a series of cyanovinyl derivatives is presented. The gas-phase basicities and acidities of (NCCHCHX, X=CH3, NH2) were obtained by means of Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry techniques. The corresponding calculated values were ob...

The gas-phase lithium cation basicities (LCB values, Gibbs free energies of binding) of alpha,omega-diphenylalkanes Ph-(CH(2))(n)-Ph (n=2, 3, or 7) and 1,1-diphenylethane Ph-CH(Me)-Ph were investigated by means of Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry. Their structures, and those of the corresponding Li(+) complexes we...

Abstract: 1) Protonation at all possible sites of adamantane (C10H16) was stud- ied at the MP2/6-311++G A C H T U N G T R E N N U N G (3df,2p)// MP2/6-311++G A C H T U N G T R E N N U N G (d,p) level. This pro- vided values of the changes in the ther- modynamic state functions for these processes. Whenever direct comparison was possible, the agreem...

In relation to the interaction between (137)Cs and soil organic matter, electrospray mass spectrometry experiments and density functional theory (DFT) calculations were carried out on the dissociation of positively charged adducts formed by cesium nitrate and cesium organic salts attached to a cesium cation [Cs(CsNO(3))(CsA)](+) (A = benzoate, sali...

The gas-phase acidity of CH3-CH2XH (X=S, Se, Te), CH2=CHXH (X=S, Se, Te) and PhXH (X=S, Se) compounds was measured by means of Fourier transform ion cyclotron resonance mass spectrometry. To analyze the role that unsaturation plays on the intrinsic acidity of these systems, a parallel theoretical study, in the framework of the G2 and the G2(MP2) th...

The gas-phase basicities (GBs) of 12 nicotinoids were calculated for the two potential sites of protonation, the sp2 pyridine and the sp3 amino nitrogen atoms, at the B3LYP/6–311 + G(3df,2p)//B3LYP/6–31G(d,p) level and estimated from substituent effects on the GBs of 2-substituted pyrrolidines and N-methylpyrrolidines. It was found that, in contras...

This article presents the results of a tentative application of Solid Phase Micro Extraction (SPME) to the analysis of BTEX (benzene, toluene, ethylbenzene and xylenes) at the μg/m3 level in indoor and outdoor air. The salient features of the method validation are reported. Sampling by QUALITAIR using Radiello® passive samplers, was carried out fro...

This article presents the results of a tentative application of Solid Phase Micro Extraction (SPME) to the analysis of BTEX (benzene, toluene, ethylbenzene and xylenes) at the μg/m³ level in indoor and outdoor air. The salient features of the method validation are reported. Sampling by QUALITAIR using Radiello® passive samplers, was carried out fro...

This article presents the results of an exploratory application of the Solid Phase MicroExtraction (SPME) technique to the analysis of BTEX (benzene, toluene, ethylbenzene and xylenes) at the microg/m3 level in outdoor and indoor air. The salient features of the method validation are reported. As shown by the various examples of field sampling desc...

Sources of VOC (Volatile Organic Compounds) reference-materials at ppm and ppb levels are needed for calibration of air monitoring instruments. The permeation-tube technique is considered effective for the preparation of low concentration standards of high accuracy and stability. In this work, purpose-built PTFE permeation tubes, containing benzene...

Abstract10.1002/poc.954.absThe gas‐phase basicity of 2‐(β‐aminoethyl)‐pyridine (AEP)—an agonist of the histamine H1 receptor—containing two potential basic sites (the ring N‐aza and the chain N‐amino) was obtained from proton‐transfer equilibrium constant measurements using Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR). Compa...

The energies of 14 methyl-substituted acetophenones and of their protonated forms were calculated within the framework of the density functional theory at the B3LYP/6-311+G(d,p) level. The gas-phase basicities of some members of this series were measured using Fourier transform ion cyclotron resonance mass spectrometry in order to complete the know...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.

A concerted theoretical (density-functional theory) and experimental electrospray mass spectrometry study was conducted on the formation of cesium cation adducts with small molecules taken as models of specific interactions sites in humic substances. Electrospray experiments with phenol, benzoic acid, salicylic acid, and phthalic acid, in methanoli...