bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural, Spectroscopic, and Reactivity Properties of N2S2(thioether)‐O(amide)‐Ligated HgII Complexes: The First Examples of HgII‐Mediated Amide Cleavage
Authors: Makowska‐Grzyska Magdalena M. , Doyle Kelly , Allred Russell A. , Arif Atta M. , Bebout Deborah C. , Berreau Lisa M. 
Published: March 2005

AbstractTwo mercury(II) complexes [(bmppa)Hg(ClO4)]ClO4 {1, bmppa = N,N‐bis(2‐methylthio)ethyl‐N‐[(6‐pivaloylamido‐2‐pyridyl)methyl]amine} and [(beppa)Hg(ClO4)]ClO4 {2, beppa = N,N‐bis(2‐ethylthio)ethyl‐N‐[(6‐pivaloylamido‐2‐pyridyl)‐methyl]amine} of N2S2(thioether)O(amide)‐donor chelate ligands have been prepared and characterized by X‐ray crystallography and/or spectroscopic methods. In the solid state, the HgII ion of 2 exhibits an overall coordination number of six and strong amide oxygen coordination. Comprehensive multinuclear NMR studies of 1 and 2 have yielded the first J and J coupling constants associated with a Hg–RSCH3 methyl group. In the presence of one equivalent of Me4NOH·5H2O in methanol/acetonitrile solution, theamide appendages of 1 and 2 undergo alcoholysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
From Dinuclear Zirconium(+3)‐Phosphido Complexes {[Cp2ZrP(H)R]2} to the First Neutral Zirconocene–Phosphinidene Dimers [(Cp2ZrPR)2] by P–H Dehydrogenation
Authors: Driess Matthias , Aust Joachim , Merz Klaus 
Published: March 2005

AbstractThe syntheses and structures of the new zirconium(+3) silylphosphanido complexes {[Cp2ZrP(H)R]2} 1a {Cp = η5‐C5H5; R = SiMe2C(iPr)Me2}, 1b (R = SiiPr3), and 1c (R = SiF(tBu)(2,4,6‐iPr3C6H2) are reported. The latter are easily accessible by the reaction of the lithium salts of the corresponding primary silylphosphanes with the Schwartz reagent [Cp2Zr(H)Cl] in THF at –70 °C. They can be isolated in the form of diamagnetic red‐black crystals in 68–85 % yield. The central structural motif of the complexes consists of planar (1a, 1b) and slightly puckered Zr2P2 rings (1c), and contains two d1‐Zr(+3) centers, which are antiferromagnetically coupled (super exchange, through‐bond interaction) although the transannular Zr–Zr separation is around 360 pm. Thus, the compounds have a biradicaloid electronic structure. Heating of solutions of 1a–c in toluene in the presence of Pd/C or [(Ph3P)2Pt(C2H4)] results in catalytic dehydrogenation of the P–H bonds, affording the first neutral zirconocene–phosphinidene dimers [Cp2ZrPR]23a–c in the form of deep red crystals in 72–88 % yield. The composition of the products is proven by multinuclear NMR spectroscopy, mass spectrometry and correct C,H‐combustion analyses. The molecular structures of 3a and 3c were additionally confirmed by X‐ray crystal structure analyses, showing that they consist of Zr2P2 rings with significantly shorter Zr–P distances than those observed in 1a and 1c. Interestingly, the dehydrogenation of the mostly sterically crowded derivative 1c occurs also in boiling toluene solutions without using a catalyst, but the process is prevented in a H2 atmosphere. This suggests that the Zr(+3) centers in 1c can serve as active sites for the P–H bonding activation, which, however, are deactivated in the presence of H2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Reaction Chemistry of the Carbenoid Butadienyl Complex Ion [CpCo(σ,η4‐C4HMe4)]+ Formed by Protonation of the Cyclobutadiene Complex [CpCo(C4Me4)]
Authors: Butovskii Mikhail V. , Englert Ulli , Herberich Gerhard E. , Koelle Ulrich 
Published: March 2005

AbstractThe protonation of [CpCo(C4Me4)] (1) with excess acid, which produces the carbenoid ion 3+, is shown to be reversible under conditions of low proton activity. Treatment of 3+ with one equivalent of NEt3 mainly produces 1 (60 %, isolated yield), and in DMSO the solvent acts as base transforming [3]BF4 into 1 (67 %, isolated yield). Deprotonation of [3]BF4 with excess NEt3 affords (cyclopentadienyl)[(2–5‐η)‐(3Z,4Z)‐3,4‐dimethylhexa‐1,2,4‐triene]cobalt (5) in high yield (83 %). The structure of 5 has been determined by X‐ray work. In the reaction of 3+ with pyridine four reaction channels could be unveiled by low‐temperature NMR spectroscopy: i) Reversible deprotonation to form 5 in a kinetic shunt; ii) reversible nucleophilic addition at the carbenoid center to form a pyridinium ion complex 6+ as a low‐temperature species with a terminal anti‐Me group; iii) irreversible isomerization of 6+ to the more stable stereoisomer 7+ with a terminal syn‐Me group; iv) very slow formation of 1. Using very high concentrations of pyridine (mixing at –60 °C, slowly warming to 20 °C) allowed the preparation of [7]BF4 in near quantitative yield (97 %). The pyridine rings in 6+ and 7+ display hindered rotation (NMR), and the structure of [7]CF3SO3 shows considerable steric crowding. On treatment with a large excess of CF3CO2H ( ≥ 7 equiv.) the hexatriene complex 5 quantitatively reverts to the carbenoid 3+. Reaction of 5 with (C5H5NH)CF3SO3 (–80 °C, 3 weeks) produced [6]CF3SO3 with retention of the stereochemistry at C‐4 (NMR), while the same reaction at ambient temperature and in presence of a large excess of pyridine is accompanied by stereoisomerization and afforded [7]CF3SO3 (94 %). Nucleophilic addition of excess PPh3 to 3+ gave a phosphonium salt [8]BF4, again with stereoisomerization, in near quantitative yield (98 %). Addition of CNtBu with concomitant rearrangement produced a (tert‐butylamino)cobaltocenium salt [9]CF3SO3 (90 %). Nucleophilic substitution of the pyridine moiety of 7+ with 4‐picoline gave the 4‐picoline additionproduct [10]CF3SO3 (96 %). With CN– a hexa‐2,4‐dienenitrile complex [CpCo(η4‐C4HMe4CN)] (11) was obtained (85 %), which on protonation gave an aminocobaltocenium ion [CpCo{C5Me4(NH2)}]+ (12+), isolated as [12]BF4 (94 %). Acid removes the pyridine moiety from 7+ to produce a carbenoid ion 13+ with a 4‐Me group in syn‐position (a stereoisomer of 3+) which was characterized by NMR spectroscopy. Deprotonation of 13+ affords a hexatriene complex 14 (a stereoisomer of 5) in good yield (57 %). Thermolyses of 5 and 14 show that 14 is the lower‐energy isomer and produce a dinuclear complex [(μ‐C5H3Me3)(CoCp)2(Co–Co)] (15) (91 %) with a bridging penta‐2,4‐dienylidene ligand. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Ab‐initio Powder Structure Determination of Dichloro[1,2‐ethanediylbis(iminomethylene)bis(phosphonato)]trizinc Dihydrate (Eur. J. Inorg. Chem. 5/2005)
Authors: Bestaoui Naima , Bakhmutova‐Albert Ekaterina V. , Rodriguez Ana Vega , Llavona Ricardo , Clearfield Abraham 
Published: March 2005

AbstractThe cover picture shows the richness of 1,2‐ethanediylbis(iminomethylene)bis(phosphonic acid) (H4L) used as a ligand. The left compound is cadmium phosphonate, Cd2Cl2(H2O)4(H2L), in which the Cd atoms form dimers through bridging chloride ions. These dimers are, in turn, formed into rows by the phosphonate groups, and the rows are crosslinked by the organic chain of the ligand into layers. The second picture shows Zn3Cl2(H2L)2·2H2O, in which Zn atoms are tetrahedrally coordinated. One of the Zn atoms lies in rows parallel to the b‐axis, which are sandwiched between rows formed by the two other Zn atoms. The carbon−nitrogen chains crisscross each other forming a three‐dimensional structure. The structure of this latest compound is presented in the article by A. Clearfield et al. on p. 829 ff.
4‐ and 4,5‐Substituted N‐Methoxythiazole‐2(3H)‐thiones – Preparation,UV/Vis Spectra, and Assignment of Electronic Transitions in Comparison to N‐Methoxypyridine‐2(1H)‐thione Using Time‐Dependent Density Functional Theory Calculations
Authors: Hartung Jens , Špehar Kristina , Svoboda Ingrid , Fuess Hartmut , Arnone Mario , Engels Bernd 
Published: March 2005

AbstractExperimentally observed absorptions in UV/Vis spectra of N‐methoxy‐4‐methylthiazole‐2(3H)‐thione, N‐methoxy‐5‐(p‐methoxyphenyl)‐4‐methylthiazole‐2(3H)‐thione, N‐methoxypyridine‐2(1H)‐thione, and selected N‐hydroxy derivatives thereof have been assigned to π→π*‐type transitions as dominating character, using the results from ab initio calculations [time‐dependent density functional theory (TD)RI‐BLYP/TZVPP]. Theory further predicts that electronic excitations in N‐methoxythiazole‐2(3H)‐thiones on one side and N‐meth‐oxypyridine‐2(1H)‐thione on the other side differ significantly with respect to character and statistical weight of contributing transitions. These effects originate predominantly from contributions of the endocyclic sulfur atom onto orbital energies and shapes in thiazole‐2(3H)‐thiones, and may be intensified by substituents such as a p‐methoxyphenyl group located in position 5. Since the majority of the calculated spectral differences between thiazole‐ and pyridinethiones refers to excitations of low intensity, the findings from the present study correlate with two important experimental facts: (i) Apart from minor shifts in the exact spectral location of UV/Vis absorptions, electronic spectra of N‐hydroxy‐ or N‐methoxy‐substituted pyridine‐2(1H)‐thiones and thiazole‐2(3H)‐thiones are surprisingly similar in shape. (ii) N‐alkoxypyridine‐2(1H)‐thiones and N‐alkoxythiazole‐2(3H)‐thiones liberate upon UV/Vis excitation oxygen‐centered radicals with a comparable efficiency. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Evaluation of Cu–Ethylenediamine Metal Ion Buffers as Calibrants for Ion‐Selective Electrode Measurement of Copper in Fresh Water Systems
Authors: Zeng Zhi Ling , Menzies Neal W , Kerven Graham 
Published: March 2005

AbstractAn investigation was made into the accuracy of cupric ion selective electrode (ISE) measurement of Cu in solutions approximating acidic freshwaters with Cu‐ethylenediamine buffers used as the calibrants. This method overestimates the free Cu compared with calibration using Cu(NO3)2 standards, the standard addition method, and speciation modelling calculations. Statistical tests showed a small, but significant, difference between the intercepts of the linear Nernstian regressions of the calibration plots of Cu‐en buffer standardisation and direct calibration with Cu(NO3)2 standards in matrix that matches the samples. The difference in the intercepts, which corresponds with Eo values of the electrode, is not well understood, but is possibly caused by potentially interfering cations such as Fe2+. The results of this study showed that down to 10−8 M Cu2+, where a linear Nernstian response is possible, the Cu ISE is probably better calibrated using Cu standards prepared in the same matrix as the sample solutions to avoid potential matrix effects.
Turbulent flow over a dune: Green River, Colorado
Authors: Venditti Jeremy G. , Bauer Bernard O. 
Published: March 2005

AbstractDetailed echo‐sounder and acoustic Doppler velocimeter measurements are used to assess the temporal and spatial structure of turbulent flow over a mobile dune in a wide, low‐gradient, alluvial reach of the Green River. Based on the geometric position of the sensor over the bedforms, measurements were taken in the wake, in transitional flow at the bedform crest, and in the internal boundary layer. Spatial distributions of Reynolds shear stress, turbulent kinetic energy, turbulence intensity, and correlation coefficient are qualitatively consistent with those over fixed, two‐dimensional bedforms in laboratory flows. Spectral and cospectral analysis demonstrates that energy levels in the lee of the crest (i.e. wake) are two to four times greater than over the crest itself, with minima over the stoss slope (within the developing internal boundary layer). The frequency structure in the wake is sharply defined with single, dominant peaks. Peak and total spectral and cross‐spectral energies vary over the bedform in a manner consistent with wave‐like perturbations that ‘break’ or ‘roll up’ into vortices that amalgamate, grow in size, and eventually diffuse as they are advected downstream. Fluid oscillations in the lee of the dune demonstrate Strouhal similarity between laboratory and field environments, and correspondence between the peak frequencies of these oscillations and the periodicity of surface boils was observed in the field. Copyright © 2005 John Wiley & Sons, Ltd.
Interferon gamma promotes survival of lymphoblasts overexpressing 9‐O‐acetylated sialoglycoconjugates in childhood acute lymphoblastic leukaemia (ALL)
Authors: Ghosh Shyamasree , Bandyopadhyay Suman , Mallick Asish , Pal Santanu , Vlasak Reinhard , Bhattacharya Dilip K. , Mandal Chitra 
Published: March 2005

AbstractAn enhanced linkage‐specific 9‐O‐acetylated sialic acid (9‐O‐AcSA) on peripheral blood mononuclear cells (PBMC) of children with acute lymphoblastic leukaemia, ALL (PBMCALL, 9‐O‐AcSA+ cells) was demonstrated by using a lectin, Achatinin‐H, whose lectinogenic epitope was 9‐O‐AcSAα2‐6GalNAc. Our aim was to evaluate the in vitro contributory role of this glycotope (9‐O‐AcSAα2‐6GalNAc) towards the survival of these 9‐O‐AcSA+ cells in ALL patients. For direct comparison, 9‐O‐AcSA− cells were generated by removing O‐acetyl group of 9‐O‐AcSA present on PBMCALL using O‐acetyl esterase. An elevated level of serum interferon gamma (IFN‐γ) in affected children led us to think that PBMCALL are continuously exposed specifically to this cytokine. Accordingly, 9‐O‐AcSA+ and 9‐O‐AcSA− cells were exposed in vitro to IFN‐γ. A twofold increased NO release along with inducible NO synthase (iNOS) mRNA expression by the 9‐O‐AcSA+ cells was observed as compared to the 9‐O‐AcSA− cells. The decreased viability of IFN‐γ exposed 9‐O‐AcSA− cells as compared to 9‐O‐AcSA+ cells were reflected from a 5.0‐fold increased caspase‐3‐like activity and a 10.0‐fold increased apoptosis in the 9‐O‐AcSA− cells when production of NO was lowered by adding competitive inhibitor of iNOS in reaction mixture. Therefore, it may be envisaged that a link exists between induction of this glycotope and their role in regulating viability of PBMCALL. Taken together, it is reasonable to hypothesise that O‐acetylation of sialic acids on PBMCALL may be an additional mechanism that promotes the survival of lymphoblasts by avoiding apoptosis via IFN‐γ‐induced NO production. © 2004 Wiley‐Liss, Inc.
Removal of chromium(III) from tannery effluents, using a system of packed columns of zeolite and activated carbon
Authors: Covarrubias Cristian , Arriagada Renán , Yáñez Jorge , García Rafael , Angélica Maria , Barros SD , Arroyo Pedro , Sousa‐Aguiar Eduardo Falabella 
Published: March 2005

AbstractThe removal of chromium(III) in packed columns of zeolite and activated carbon has been studied. The process of Cr(III) exchange in 13X zeolite was optimized using mass transference parameters. In addition, the effects of pH, the presence of interfering ions and the anion associated with the chromium in the solution were studied. It was found that particle diameter controls the Cr(III) exchange in the zeolite, indicating that particle diffusion predominantly controls the process of Cr(III) exchange in 13X zeolite. A mixed system of zeolite and activated carbon columns increased the efficiency of chromium removal from diluted wastewater. This effect occurred due to the reduction of the organic matter (chemical oxygen demand), adsorption of chromium, and interfering ions on the activated carbon column. The activated carbon + zeolite column system emerges as an alternative method in Cr(III) removal from tannery effluents. Copyright © 2005 Society of Chemical Industry
Familial clustering of muscular and cardiac involvement in myotonic dystrophy type 1
Authors: Groh William J. , Lowe Miriam R. , Simmons Zachary , Bhakta Deepak , Pascuzzi Robert M. 
Published: March 2005

AbstractMyotonic dystrophy type 1 (DM1) is associated with both skeletal and cardiac muscle involvement. The aim of the present study was to determine whether familial clustering is observed in the severity of muscle involvement in DM1. We evaluated 51 sibling groups constituting 112 patients with genetically‐verified DM1. The siblings were similar to each other in age, cytosine‐thymine‐guanine (CTG) repeat length, age at disease onset, muscular impairment rating score, and electrocardiographic markers of cardiac conduction disease. After adjusting for the similarities between siblings in age and CTG repeat length, the siblings remained similar to each other in measures of both skeletal and cardiac muscle involvement. These results suggest that factors other than CTG repeat length play a role in the severity and progression of the degenerative skeletal and cardiac muscle disease in DM1. Muscle Nerve, 2005
Fluorene‐based alternating polymers containing electron‐withdrawing bithiazole units: Preparation and device applications
Authors: Lee Jaemin , Jung Byung‐Jun , Lee Sang Kyu , Lee Jeong‐Ik , Cho Hoon‐Je , Shim Hong‐Ku 
Published: March 2005

AbstractWe report here the synthesis via Suzuki polymerization of two novel alternating polymers containing 9,9‐dioctylfluorene and electron‐withdrawing 4,4′‐dihexyl‐2,2′‐bithiazole moieties, poly[(4,4′‐dihexyl‐2,2′‐bithiazole‐5,5′‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)] (PHBTzF) and poly[(5,5′‐bis(2″‐thienyl)‐4,4′‐dihexyl‐2,2′‐bithiazole‐5″,5″‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)] (PTHBTzTF), and their application to electronic devices. The ultraviolet–visible absorption maxima of films of PHBTzF and PTHBTzTF were 413 and 471 nm, respectively, and the photoluminescence maxima were 513 and 590 nm, respectively. Cyclic voltammetry experiment showed an improvement in the n‐doping stability of the polymers and a reduction of their lowest unoccupied molecular orbital energy levels as a result of bithiazole in the polymers' main chain. The highest occupied molecular orbital energy levels of the polymers were −5.85 eV for PHBTzF and −5.53 eV for PTHBTzTF. Conventional polymeric light‐emitting‐diode devices were fabricated in the ITO/PEDOT:PSS/polymer/Ca/Al configuration [where ITO is indium tin oxide and PEDOT:PSS is poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonic acid)] with the two polymers as emitting layers. The PHBTzF device exhibited a maximum luminance of 210 cd/m2 and a turn‐on voltage of 9.4 V, whereas the PTHBTzTF device exhibited a maximum luminance of 1840 cd/m2 and a turn‐on voltage of 5.4 V. In addition, a preliminary organic solar‐cell device with the ITO/PEDOT:PSS/(PTHBTzTF + C60)/Ca/Al configuration (where C60 is fullerene) was also fabricated. Under 100 mW/cm2 of air mass 1.5 white‐light illumination, the device produced an open‐circuit voltage of 0.76 V and a short‐circuit current of 1.70 mA/cm2. The fill factor of the device was 0.40, and the power conversion efficiency was 0.52%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1845–1857, 2005
Recent trends from Canadian permafrost thermal monitoring network sites
Authors: Smith Sharon L. , Burgess Margo M. , Riseborough Dan , Mark Nixon F. 
Published: March 2005

AbstractThe Geological Survey of Canada (GSC), in collaboration with other government partners, has been developing and maintaining a network of active‐layer and permafrost thermal monitoring sites which contribute to the Canadian Permafrost Monitoring Network and the Global Terrestrial Network for Permafrost. Recent results from the thermal monitoring sites maintained by the GSC and other federal government agencies are presented. These results indicate that the response of permafrost temperature to recent climate change and variability varies across the Canadian permafrost region. Warming of shallow permafrost temperatures of between 0.3 and 0.6°C per decade has occurred since the mid‐ to late 1980s in the central and northern Mackenzie region in response to a general increase in air temperature. No significant warming (less than 0.1°C per decade) of permafrost is observed in the southern Mackenzie valley. Warming of shallow permafrost of between 1.0 and 4.0°C per decade is also observed in the eastern and high Arctic, but this mainly occurred in the late 1990s. These trends in permafrost temperature are consistent with trends in air temperature observed since the 1970s. Local conditions however, influence the response of the permafrost thermal regime to these changes in air temperature. Copyright © 2005 John Wiley & Sons, Ltd.
Photoluminescence and photomodulated transmittance spectroscopy of ZnO nanowires
Authors: Ozaki S. , Tsuchiya T. , Inokuchi Y. , Adachi S. 
Published: March 2005

AbstractZnO nanowires have been synthesized by a simple vapor transport method of heating the mixture of zinc oxide and carbon powders in an open tube of the furnace. The scanning‐electron‐microscopy images show that the average diameters of the nanowires deposited on quartz substrates for t = 20 and 40 min are ∼20 and ∼40 nm, respectively. Low‐temperature (77 K) photoluminescence (PL) spectrum in ZnO nanowires shows a sharp emission at 3.36 eV due to excitons bound to neutral donors. Spectral analysis also suggests a peak of biexciton emission at ∼3.35 eV. The biexciton binding energy determined here is ∼17 meV, in agreement with previous results. Photomodulated transmittance (PT) spectroscopy has been used to investigate the E0 critical‐point structures in ZnO nanowires. The measured PT spectrum shows distinct structures at ∼3.3–3.5 eV. These structures are found to be mainly due to excitonic transitions at the E0 edge. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoreflectance spectroscopy of step‐like GaInNAs/GaInNAs/GaAs quantum wells
Authors: Kudrawiec R. , Andrzejewski J. , Misiewicz J. , Gollub D. , Forchel A. 
Published: March 2005

AbstractPhotoreflectance (PR) spectroscopy has been applied to study of step‐like GaInNAs/GaInNAs/GaAs double quantum well (DQW) structures grown by molecular beam epitaxy. PR features related to optical transitions in the active part of the step‐like QW structure, i.e. GaInNAs/GaInNAs QW, as well as PR features related to transitions above the step‐like barrier (SLB) have been clearly observed and analysed in this paper. The analysis of the QW transitions gives information about the number of confined states in the active part of the step‐like QW structure. In addition, the analysis of the second portion of PR signal gives information about the band gap energy of the SLB and optical transitions between hole and electron levels confined above the SLB. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pyridine N‐oxide and pyridine‐d5N‐oxide: an electrospray/tandem mass spectrometric study carried out at high mass resolution
Authors: March Raymond E. , Stadey Christopher J. , Lewars Errol G. 
Published: March 2005

AbstractA mass spectrometric study of pyridine N‐oxide and pyridine‐d5 N‐oxide was carried out with a hybrid quadrupole/time‐of‐flight (TOF) mass spectrometer coupled with an electrospray (ES) source. In addition to the observation of protonated, sodiated, and proton‐bound dimers of pyridine N‐oxide and pyridine‐d5 N‐oxide, mass scans revealed the presence of several doubly‐charged ion species. Doubly‐charged ions of m/z 191 were identified as diprotonated tetramers of pyridine N‐oxide; a structure has been proposed for the diprotonated tetramer and its energy relative to that of protonated pyridine N‐oxide has been obtained from geometry optimizations. The principal ion species observed were subjected to collision‐induced dissociation; accurate mass measurements were made of each fragment ion so as to determine its elemental composition. On the basis of mass spectrometric evidence, it is suggested that dissociation of pyridine N‐oxide may occur during the ES process and the resulting fragments become embedded in doubly‐charged ions. The proton affinity for both pyridine N‐oxide and pyridine‐d5 N‐oxide was calculated; the difference between these proton affinities was compared with an experimentally determined difference between the proton affinities of pyridine N‐oxide and pyridine‐d5 N‐oxide. Copyright © 2005 John Wiley & Sons, Ltd.