bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemical Substitution of fac‐Tricarbonyl[P,P′,S‐ (2,2‐Bis (diphenylphosphinomethyl)‐1‐Phenylthiopropane) ]manganese(I) Hexafluorophosphate by Diphenylphosphine
Authors: Tsai Shiou‐Chuan , Cheng Ming‐Chu , Peng Shic‐Ming , Liu Shiuh‐Tzung 
Published: May 2015

AbstractThe title complex underwent ligand substitution by diphenylphosphine to form dicarbonyl[P,P′,S‐(2,2‐bis(diphenylphosphinoniethyl)‐1‐phcnylthiopropane](diphenylphospline)manganesc(I) hexafluorophosphate 2 under photochemical conditions. The crystal structure of complex 2 was determined. The reaction was kinetically independent of the concentration of diphenylphosphine, so a first‐order reaction.
Extended Fluorescence Quenching Analysis as a Remote Probe of Non‐Emissive Exciplexes
Authors: Chow Yuan L. , Johansson Carl I. 
Published: May 2015

AbstractExtended fluorescence quenching analysis is demonstrated to be an efficient steady‐state method to evaluate the exciplex (excimer) rate constants under certain conditions. This method is attractive as the monitor of only fluorescence of the exciplex's precursor is required for a complete analysis, regardless whether or not the exciplex. Using the interaction of methyl 2‐naphlhoate in its singlet excited state with H2S04 as a kinetic model, for which all the rate constants are known, this method is described and shown to reproduce accurately these rate constants. Limitations and applications of this method are discussed.
Photochemistry of Bicyclo[2.2.2]oct‐5‐Ene‐2,3‐Diones and Reactions of the Intermediates Bicyclo[4.2.0]oct‐2‐Ene‐7,8‐Diones
Authors: Liao Chun‐Chen , Ueng Yih‐Gang 
Published: May 2015

AbstractIrradiation of bicyclo[2.2.2]oct‐5‐ene‐2,3‐diones la‐c proceeded quantitatively via 1,3‐acyl shifts to yield the corresponding bicyclo[4.2.0]oct‐2‐ene‐7,8‐diones 2a‐c that underwent bisdecarbonylation to afford also quantitatively 1,3‐cyclohexadienes 3a‐c upon further excitation. In contrast the thermolysis of 2c produced lc and 4; the kinetic parameters were found to be ΔH≠ = (90.4 ± 0.8) kJ mot.1 and ΔS≠ = (−12.1 ± 0.1) J K−1 mol−1.
A New Synthesis of Pyrrolo‐3‐Sulfolenes
Authors: Chou Ta‐Shue , Tsai Chung‐Ying 
Published: May 2015

AbstractA short and novel synthetic route toward pyrrolo‐3‐sulfolene and its N‐mesyl derivative, precursors for the corresponding pyrrolo o‐quinodimethanes, has been developed. The synthesis involves ultrasonic zincation of 4‐bromo‐3‐chloro‐2‐sulfolene and an N‐protected 2‐aminoaldehyde, intramolecular conjugate addition, dehydration and isomerization.
A Convenient Synthesis of 2‐Diazo‐1,3‐Dicyano‐6‐Oxo‐2,6‐Dihydroazulene and its Photochemical Reactions
Authors: Wun Wu‐Che , Huang Tian‐Chyuan , Lin Shih‐Jue , Lin Bing‐Bing , Morita Tadayoshi , Lin Yun‐Shan 
Published: May 2015

AbstractA facile method was found to synthesize a novel azulenequinone 2‐diazo‐1,3‐dicyano‐6‐oxo‐2,6‐dihydroazulene 4, in yield 90% from the reaction of 2‐amino‐6‐bromo‐1,3‐dicyanoazulene 2 with sodium nitrite in trifluoroacetic acid at 0 °C. The reaction of 4 with methanol, ethanol, acetic acid, benzene, toluene and acetonitrile in photochemical conditions gave related products in yields 82, 82, 90, 85, 40 and 95% of 2‐substituted‐6‐hydroxyazulene derivatives respectively.
Modulation of Troponin‐C Binding to Troponin‐T by Ca2+, Probed by Fluorescence
Authors: Lin Tsung‐I , Mayadevi M. , Dowben R. M. 
Published: May 2015

AbstractThe effects of Ca2+ on the binding interaction between troponin‐C (TnC) and troponin‐T (TnT) and between TnC and troponin‐I (TnI) were studied in both the binary complexes and the presence of other subunits and tropomyosin (Tm). Rabbit skeletal TnC was labeled with 7‐dimemyl‐amino‐4‐methyl‐3‐N′‐meleimido‐coumarin (DACM). The fluorescence titration curve of the labeled TnC with Ca2+ showed a biphasic response; fluorescence was quenched (by 31%) initially but increased (by 64%) in the second phase. In the presence of CaCl2 (3 mM), titrating labeled TnC with TnT caused further fluorescence enhancement (32–34%) of DACM by TnT. In the absence of Ca2+, TnT bound weakly to TnC (Ka < 103 M−1) whereas in the presence of Ca2+, the TnT‐TnC binding affinity increased almost 1000 fold (Ka = 0.42 × 106 M−1). The affinity constant of unlabeled TnC for TnT is 10 – 15 times that of the labeled complex (Ka = (3.4∼ 5.1) × 106 M−1); this value was determined from the binding isotherm of a mixed system consisting of labeled and unlabeled TnC at a fixed ratio upon titration with TnT. Adding Tm to the system weakened the binding of TnT to TnC by at least 50 – 60 percent. Adding Tnl to DACM‐TnC alone also enhanced the fluorescence (20–22%). An affinity constant 108. M−1 for TnC‐Tnl binary complex was obtained. If Tn‐I and the labeled TnC were premixed first in 1:1 stoichiometry, then titrated with TnT, a further fluorescence increase (34%) similar to that in the absence of TnI was observed. The fit of the binding curve shows that Ka of TnT to TnC increased (1.5 × 106 M−1). When TnI was added to the TnC‐TnT complex at the end of titration when the fluorescence binding curve became leveled, quenching (12%) occurred. The latter result indicates that TnI competes with TnT for the same binding sites on TnC. As binding of TnC is at least 100 times as strong to TnI as to TnT, a quenching effect is observed. Furthermore, the conformation of TnC in the TnC‐TnI binary complex may vary from that of TnC alone; binding of TnT to TnC is greatly enhanced (directly or in directly by TnI) in the TnC‐TnI complex. These results indicate that the variation of binding affinity between TnC and TnT as modulated by Ca2+ may play an important role in the Ca+2‐regulation mechanism of muscle contraction.
Syntheses and Characterization of Diastereoisomers of 2′‐O‐Methyladenylyl‐3′,5′‐2′‐O‐Methyladenosine Methyl Phosphonates and 2′‐O‐Methyladenylyl‐3′,5′‐2′‐O‐Methyladenosine Ethylphosphotriesters
Authors: Kan Lou‐Sing , Lin Pen‐Yuan , Yano Junichi 
Published: May 2015

AbstractThe synthesis, separation, purification, and characterization of the R‐ and S‐ forms of 2′‐O‐methyladenylyl‐3′,5′‐2′‐O‐methyladenosine methyl phosphonates ((AmpAm)R or s), 2′‐O‐methyladenylyl‐3′,5′‐2′‐O‐methyladenosine ethylphosphotriesters ((Am(Et)Am)H or s), and 2′‐O‐methyladenylyl‐3′,5′‐2′‐O‐methyladenosine are described.
Formation of Triplexes of Diastereoisomers of 2′‐O‐Methyladenylyl‐3′,5′‐2′‐O‐Methyladenosine Ethylphosphotriesters and 2′‐O‐Methyladenylyl‐ 3′,5′‐2′‐O‐Methyladenosine Methyl Phosphonates with Polyuridylic Acid and Polythymidylic Acid: A Steric Effect
Authors: Kan Lou‐Sing , Koo William , Yano Junichi 
Published: May 2015

AbstractThe triplex formation of diastereoisomers of 2′‐O‐methyladenylyl‐3′,5′‐2′‐O‐methyladenosine ethylphosphotriesters and 2′‐O‐methyladenylyl‐3′,5′‐2′‐O‐methyladenosinc methyl phosphonates with polyuridylic acid and polythymidylic acid was monitored by UV spectral mediods. Possible steric effects on the stability of the triplex are discussed with the aid of simulated chemical structures.
Distribution of Europium Ions in Ion‐Exchanged NaX and NaY Zeolites
Authors: Liu Shang‐Bin , Shu Yau‐Jen , Chang Chau‐Ting 
Published: May 2015

AbstractThe chemical environments of europium‐exchanged NaX (Si/Al =1.16) and NaY (Si/Al = 2.29) zeolites have been investigated by means of 129Xe NMR and isotherm measurements of adsorbed xenon. EuNaX and EuNaY samples with varied concentrations of Eu cations were subjected to diverse chemical and thermal treatments, namely dehydration, reduction, oxidation, and re‐reduction.Thermal analyses of hydrated EuNaX and EuNaY samples indicate that both the structural stability and the saturation concentration of water increase with increasing Eu content. For dehydrated EuNaY zeolites, the Eu3+ cations tend to replace Na+ ions at S2 sites and tend to be located in framework supercages; similar behavior is found for Eu2+ ions after reduction. After subsequent oxidation, Eu3+ ions migrate from supercages into small sodalite and/or D6R cages; similar results were deduced for samples after re‐reduction. In contrast to the behavior observed in EuNaY, Eu3+ ions tend to exchange for Na+ ions in the sodalite and/or D6R cages in dehydrated EuNaX zeolites, regardless of the thermal treatment; this behavior is ascribed to the existence of unlocalized S3 Na+ in EuNaX samples.
Syntheses and Crystal Structures of Bis‐Citrato, Bis‐Citramalato and Bis‐Malato Germanate(IV) Complexes
Authors: Chiang Hung‐Cheh , Yang Kao‐Chu , Ueng Chuen‐Her 
Published: May 2015

AbstractBis‐citrato1a‐d, bis‐citramalato2and bis‐malato3germanate(IV) complexes were synthesized from germanium dioxide and citric acid, citramalic acid and malic acid respectively and were identified with IR, NMR and elementary analysis. Crystal 1a is triclinic, space group P1 with a = 7.919(2), b = 7.968(3), c = 9.605(3) Å, α = 94.25(3), β = 108.03(2), γ= 113.05(3)°, Z = 1, and the final residue, R(F), is 0.033 for 2583 reflections. Crystal 2 is monoclinic, space group C2 with a = 10.226(4), b = 12.802(4), c = 6.141(1) Å, β = 100.75(2)°, Z = 2, and the final residue, R(F), is 0.034 for 934 reflections. Both1aand2have slightly distorted octahedral structures with citrate or citramalate ions as a tridentate ligand that forms five‐, six‐ and seven‐membered rings with the central metal. There is a two‐fold axis through the central atom of compound2instead of the inversion center of1a. Same structures for these six complexes are indicated because the spectral patterns of the other four compounds,1b‐dand3, are similar to those of compounds1aand2.
Synthesis of Aryl α,α‐Difluoroalkyl Ketones as Potent Inhibitors of Cholesterol Esterase
Authors: Lin Gialih , Liu Hsiao‐Chien , Wu Fang‐Chen , Chen Show‐Jane 
Published: May 2015

AbstractAryl α,α‐difluoroalkyl ketones were synthesized from the reaction of ethyl α,α‐difluoroacylate with aryl lithium at −78°C or from the coupling of aryl iododifluoromethyl ketone with 1‐alkene in the presence of tetcrakis(triphenylphosphine)palladium(0). These compounds were potent inhibitors of pancreatic cholesterol esterase with Ki values in the range 15 μM‐20 nM.
Determination of Organophosphorus Pesticides in Water Using C18 or Florisil Sep‐Pak Cartridge and Gas Chromatography with Flame‐Photometric Detection
Authors: Wang Wan‐Kung , Huang Shang‐Da 
Published: May 2015

AbstractSimple methods for the concentration and clean‐up of fifteen organophosphorus pesticides in water using a C18 Sep‐Pak cartridge or a Florisil Sep‐Pak cartridge and subsequently determining the pesticides by gas chromatography with flame photometric detection have been developed. The conditions for stepwise or simultaneous desorption of these pesticides from the Sep‐Pak cartridges are given.
Determination of Trace Arsenic and Selenium in Water Samples by Inductively‐Coupled‐Plasma Mass Spectrometry
Authors: Jiang Shiuh‐Jen , Lu Pei‐Ling , Huang Meng‐Fen 
Published: May 2015

AbstractUtilisation of a miniature anion‐exchanger preconcentration column of Dowex 1‐X8 to increase the sensitivity for As and Se determinations by inductively‐coupled‐plasma mass spectrometry (ICP‐MS) is described. The ion signal was enhanced were 15 fold for As and 20 fold for Se. The multielement detection limits were 2 ppt (ng/L) and 33 ppt for As and Se, respectively. This flow injection ICP‐MS method was applied to the determination of trace levels of arsenic and selenium in riverine reference material SLRS‐2 and spring water samples.
Isomerization and Disproportionation of 1,2,4‐Trimethylbenzene over HY Zeolite
Authors: Ko An‐Nan , Kuo Ching Tung 
Published: May 2015

AbstractThe conversion of 1,2,4‐trimethy]benzene (1,2,4‐TMB) over HY zeolite was studied at atmosoheric pressure and 200–300 °C by using a fixed‐bed, integral‐flow reactor. The types and initial selectivities of various products were obtained from plots of product selectivity according to the time‐on‐stream theory. The primary reaction included the isomerization and the disproportionation; the former led to the simultaneous formation of 1,2.3‐ and 1,3,5‐TMB whereas the latter produced all isomers of xylene and tetramethylbenzene. The relative initial rate of disproportionation to isomerization decreased from 12.6 at 200 °C to 5.47 at 300 °C. The activation energies for the primary reactions were estimated and compared with those in the reaction of 1,2,3‐TMB.
The Chemistry of Binor‐S and its Cyclopropyl Ring Transformations
Authors: Yang Ya‐Ping , Ding Mei‐Fang , Wang Yu‐Wen , Cheng Shu‐Chun , Li Chun‐Lien , Chen Yao‐Jung , Wen Yuh‐Sheng , Jiang Tsong‐Shing , Chow Tahsin J. 
Published: May 2015

AbstractSelective ring opening of the cyclopropyl moiety of binor‐S was accomplished by several methods including acidic hydrolysis, bromination, and bydrobromination. The crystal structure of dibromide adduct 3 was solved by X‐ray diffraction analysis. Debrominations of 3 yielded either 1 or 4a, whereas dehydrobromination yielded a 3‐substituted monobromide 6a. The mechanism of conversion of 3 to 6a is depicted as involving intermediate 7; the existence of 7 is supported by the isolation of olefin 8. Oxidation of alcohol 4c produced ketone 11a which was either oxidized to lactone 12 or transformed to a methylene derivative 11b. Hydroboration of 11b followed by quenching with hydrogen peroxide produced a hydroxymethyl derivative 14.
Electrochemical Oxidations of Central Nervous System Indoleamines, Catecholamines and Alkaloids: Potential Significance into Neurodegenerative Diseases
Authors: Wrona Monika Z. , And Fa Zhang , Dryhurst Glenn 
Published: May 2015

AbstractThe serotonergic neurotransmitter 5‐hydroxytryptamine (5‐HT), the catecholaminergic neurotransmittcr dopaminc (DA) and various tetrahydroisoquinoline (TIQ) and tetrahydro‐β‐carboline (THβC) alkaloids are all easily oxidized compounds. Aberrant oxidative transformations of 5‐HT and other central indoles might be involved in neurodegenerative Alzheimer's Disease (AD). Changes in the oxidation chemistry of DA appear to be fundamental in substantia nigra neurons in Parkinson's Disease (PD). Various TIQ and THβC alkaloids are elevated in the brain as a result of ethanol drinking. Recent studies into the electrochemical oxidation chemistry of 5‐HT, DA and various TIQ and THβC alkaloids have been reviewed. The potential roles of the oxidation chemistry of these compounds in neurodegenerative AD, PD and alcoholism are discussed.
Classical Cascade Calculations on the Analysis of Surface Bonding Structures by Secondary Particle Mass Spectrometry
Authors: Chang Che‐Chen 
Published: May 2015

AbstractThe application of secondary particle mass spectrometry to analyze the atomic bonding configuration on a surface was investigated with computer calculations of particle sputtering from an Ar‐bombarded surface of Ag{111}. In contrast to the prediction from the present sputtering theory, better resolved structure in the angular distribution was not observed for particles of high energy sputtered from the surface. These particles ejected to a wide angle and their angular distribution may not reflect well the atomic bonding geometry on the surface. The analytical capability of secondary particle mass spectrometry to determine surface structures can be significantly improved by selecting for detection only those particles that have prolonged collisions. The preferred directions of ejection and the relative sputtering intensity in the distribution of azimuthal angle between major open channels on the surface vary insignificantly with the duration of collision in the regime of long collisions. The results provide the first evidence that at small energies of sputtering the particles emitted from the surface may contain information about only the top two surface layers. Secondary particle mass spectrometry can thus be extremely surface sensitive for analysis of properties of solid surfaces.
Solid‐State Oxygen and Hydrogen Sensing Devices Based on Copper Dicyanoanthraquinone Diimines
Authors: Wang Chong Mou , Lin Huh‐Lerng , Wang Wehn‐Ying , Cheng Hwang Yaw , Liu Lilian Kao 
Published: May 2015

AbstractSubstituted dicyanoanthraqumone diimines (DCNAQI) and their related copper complexes, Cu(DCNAQI), have been synthesized and characterized. Most Cu(DCNAQI) complexes possess an activation energy 80–400 meV and strongly absorb in the IR range. Electrochemical investigations with polycrystailine electrodes as thin films reveal that Cu(DCNAQI) behaves as an n‐type semiconductor. Under bandgap excitation (4000 cm−1), the photoconductance measured with these Cu(DCNAQI) electrodes was greatly promoted under nitrogen, but very sensitive to O2 or H2. When the conductance difference, Δσ/σdark = (σlight ‐ σ dark)σ dark, was plotted vs the partial pressure of the target molecule, a nearly linear relationship was observed. Among Cu(DCNAQI), Cu(β‐methyl‐DCNAQI) gave the greatest senstivity for detection of hydrogen, but Cu(α,α′‐dichloro‐DCNAQI) appeared most sensitive toward oxygen. This remarkable relationship is likely due to retardation of the mobility of electron or hole by interaction with oxygen or hydrogen at the Cu(DCNAQI) electrode surface; a solid‐state oxygen/hydrogen sensing device based on these organic semiconductors is proposed.
Conformational Analysis of Biphenyl‐2,2′‐Diacetate
Authors: Lin Gialih , Chen Show‐Jane , Wu Fang‐Chen 
Published: May 2015

AbstractConformational analysis of biphenyl‐2,2′‐diacetate by dynamic NMR and UV spectra and by plots of enzyme activity vs temperature plots is described. From dynamic NMR spectra of the biphenyl‐2,2′‐diacetate with a chiral shift reagent, the coalescence temperature (Tc), the Gibbs energy of activation (ΔG≠), and the rate coefficient (k) of bipbenyl‐2,2′‐diacetate were −5 °C, 59.5 kJ/mol, and 13.3 s−1, respectively. From analysis of the conformational break in the UV spectra and the discontinuity in the plots of enzyme activity vs temperature, the racemerization temperature of bipbenyl‐2,2′‐diacetate is about 5°C.
Comparison of Stereoselectivity of Intramolecular Cyclization of Aldehydes Tethered with Conjugated Esters Induced by O‐Stannyl and O‐Samarium Ketyls to Form the Tetrahydrofuran Ring Systems
Authors: Hon Yung‐Son , Sun Pei‐Pei , Lu Hui‐Ling , Chang Nein‐Chen 
Published: May 2015

AbstractSeveral (E)‐ and (Z)‐ω‐formyl‐5‐oxa‐2‐substituted‐α,β‐unsaturated esters (6Za‐6Zc; 6Ea‐6Ec; 6Eb′‐6Ec′; 6Zb′‐6Zc′) were prepared in high yields. They were subjected to cyclization of their intramolecular ketyl radicals induced by either samarium(II) iodide or tributyltin hydride. These two reagents gave distinct stereoselectivities. More bicylic lactone than monocyclic hydroxy‐ester was formed when tributyltin hydride was used, but the opposite stereoselectivity was obtained when samarium(II) iodide was used. The effect of double‐bond configuration, heteroatom and substituent on stereoselectivity is described.
Ab Initio Calculations of Structure and Energetics of the Hypermetalated Hydrogen Oxide Molecules: Li2NaOH and LiNa2OH
Authors: Shie Yi‐Shiau , Ho Jia‐Jen 
Published: May 2015

AbstractWe made ab initio electronic calculations of the structure and energetics of mixed hypermetalated hydrogen oxides, Li2NaOH and LiNa2OH. There exist five equilibrium geometries for each complex. In all levels of calculation the global minimum structure for Li2NaOH has C2v symmetry and a large distance between sodium and oxygen, 4.24 Å (MP2/6‐31G*). The dissociation energies to all possible products were also calculated. Li2NaOH → Na + Li2OH δH = +25.33 kcal/mol (at MP4/6‐311++G**//6‐31G* + ZPE scaled by 0.9). All other dissociation processes are highly endothermic. Similar procedures were applied to LiNa2OH. The global minimum structure for LiNa2OH belongs to point group Cs. It is also endothermic to all possible dissociation paths. LiNa2OH →Na + LiNaOH δH = +12.72 kcal/mol (at MP4/6‐311++G*//6‐31G* + ZPE scaled by 0.9). The nuclear repulsion energy is crucial in energetics of the structures. The distribution of electron density and bonding properties for these equilibrium structures were analyzed.
Muttiphoton Ionization of Benzene‐Ammonia Clusters: Intracluster Reaction and Cluster Ion Stability
Authors: Tsai Wen‐Chin , Yen Wei‐Hung , Tzeng Wen‐Bih 
Published: May 2015

AbstractNeutral benzene‐ammonia clusters, prepared in a supersonic expansion, were ionized using multiphoton ionization. The cluster ions were investigated with a time‐of‐flight mass spectrometer. The observed major cluster ions, under 355‐nm laser irradiation, resulting from prompt intracluster ion‐molecule reaction and fragmentation following ionization are (C6H6)m(NH3)nH+, m = 1–6, n = 1–4 and (C6H6)m+, m = 1–3. The results of isotopic labeling experiments clearly indicate that C6H6 does not participate in intracluster ion‐molecule reactions to form (C6H6)m(NH3)nH+. A local maximum appears at n = 2 in the intensity distribution of (C6H6)m(NH3) nH+ for each value of m under all experimental conditions. This finding indicates that (C6H6)m(NH3)2H+ is more stable than any other (C6H5)m(NH3)mH+ (n = 1,3,4) for m = 1–6.
Rotational Phenomena on Substituent Phenyl Rings of (η5‐Cyclopentadienyl)(η4‐Tetraphenylcyclobutadiene)Cobalt
Authors: Lo Shih‐Chun , Keng Mei‐Yun , Chang Yuan‐Terng , Hong Fung‐E 
Published: May 2015

AbstractWe used extended Hückel calculations, variable‐temperature, homonuclear long‐range shift‐correlated 2‐D 1H NMR and dynamic NOE measurements to investigate rotational phenomena of substituent phenyl rings on (η5‐cyclopentadienyl)(η4tetraphenylcyclobutadiene)cobalt (1). Two closely related compounds, (η5‐cyclopentadienyl)(η4‐1,3‐diphenylcyclobutadiene)cobalt (A) and (η5‐cyclopentadienyl)(η4‐1,2‐diphenylcyclobutadiene)cobalt (A′), were prepared. Energy minima appeared at conformations of which the dihedral angles between phenyl and cyclobutadiene rings are about 30° for I and 0° for A according to extended Hückel calculations. In 1, ortho protons of phenyl rings belong to one set of multiplet in 1H NMR; meta and para protons belong to the other. It was supported by a long‐range coupling 2‐D 1H NMR and NOE experiments. A sharp line due to phenyl rings was observed in the low‐temperature 1H NMR spectrum of A, which indicates that the five protons are magnetically equivalent at that temperature.
Kinetics of Oxidation of Diphenylmethane and Derivatives with Ce(IV) in Aqueous Acidic Acetonitrile
Authors: Lin Hong‐Ping , Leu Jeng Rong , Jwo Jing‐Jer 
Published: May 2015

AbstractIn aqueous acidic acetonitrilc solution cerium(IV) oxidizes diphenylmethane (Ph2CH2) to produce diphenylmethanol (Ph2CHOH) first and then benzophenone (Ph2CO). With the organic reductant in great excess, both the Ce(IV)‐Ph2CH2 and Ce(IV)‐Ph2CHOH rcactions follow second‐order kinetics. The rates of both reactions increase nonlinearly with increasing [H+] or with decreasing [H2O]. Both kinetic and spectrophotometrc results indicate that replacement of water molecules by complex formation through the phenyl or hydroxyl group plays an important role in activating the reaction. Under similar conditions, the order of relative reactivities toward Ce(IV) oxidation is PhCH2OH > CH3CH2OH > Ph2CHOH > Ph2CH2 > PhCH3> (Ph2CO, C6H6). Mechanistic interpretations of the kinetic results are presented.
Monitoring of Atmospheric Sulfur Dioxide by Fluorescence Monitoring System
Authors: Chen Yehn‐Cherng , Lo Jiunn‐Guang , Wang Jough‐Tai 
Published: May 2015

AbstractA fluorescence monitoring system was used to measure gaseous sulfur dioxide at Taoyuan Agricultural Farm. A gas‐diluting system and gas chromatograph equipped with a sulfur chemiluminescence detector used to audit the accuracy of diluted sulfur dioxide are described. The accuracy was −8% and −2%, respectively, for the preparation of 10 and 50 ppb SO2 standard gas. The pattern of variation of SO2 concentration at Taoyuan Agricultural Farm is reported. In summer at Taoyuan Agricultural Farm, the concentration of SO2 varied with a pattern of night concentration (15‐20 ppb) greater than that in the afternoon (0–2 ppb). Computer‐analyzed wind trajectories in Taiwan for this pattern are reported.