Quenching of the triplet state of meso-substituted thiacarbocyanine dyes by nitroxyl radicals, iodide ions, and oxygen in solutions and in complexes with DNA

Using the flash photolysis method, the spectral and kinetic characteristics of triplet states of a number of meso-substituted thiacarbocyanine dyes (3,3′-diethyl-9-methoxythiacarbocyanine iodide, 3,3′,9-triethylthiacarbocyanine iodide, 3,3′-diethyl-9-methylthiacarbocyanine iodide, and 3,3′-diethyl-9-thiomethylthiacarbocyanine iodide) were studied, and the rate constants of triplet quenching by a stable nitroxyl radical, iodide ion, and oxygen were determined in solutions and in complexes with DNA. The results obtained show the formation of two types of dye-DNA complexes: formed by binding of the dye in the groove of a DNA molecule and by intercalation of the dye between base pairs. The complexation creates steric hindrances upon quenching of the triplet states of the ligands and causes great differences between the rate constants of the quenching processes.     

A novel synthesis of polyethers with pendant hydroxyl groups by polyaddition of bis(oxetane)s with bis(phenol)s

The polyaddition of 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene (BEOB) with 3,3′,5,5′-tetrachlorobisphenol A (TCBPA) was examined with or without catalysts. High molecular weight polymer (polymers 1) (M_n = 13,600) with pendant primary hydroxyl groups was obtained in a 99% yield without any gel products when the reaction was performed with 5 mol % of tetraphenylphosphonium bromide as a catalyst in NMP at 160°C for 96 h. However, when the reaction was carried out without a catalyst under the same conditions, a low molecular weight polymer (M_n = 3200) was obtained in a 51% yield. The structure of the resulting polymer was confirmed by IR, ¹H-NMR, and ¹³C-NMR spectra. In this reaction system, it was also found that tetraphenylphosphonium iodide and crown ether complexes such as 18-crown-6 (18-C-6)/KBr and 18-C-6/KI have high catalytic activity. Polyadditions of 1,4-bis[(3-methyl-3-oxetanyl)methoxymethyl]benzene with TCBPA and BEOB with 3,3′,5,5′-tetrabromobisphenol-S were also examined, and corresponding polymers (polymers 2 and 3) were obtained in good yields. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2781–2790, 1999     

新轴手性N,N-Dioxide Biscarbolin衍生物催化酮亚胺的不对称硅氢化反应

以L-色氨酸为原料合成了5个伯酰胺结构的轴手性双咔啉N—O催化剂N2,N2'-二氧-9,9'-二甲基-3,3'-取代甲酰胺-β-双咔啉(4A~4E),并用于不对称催化酮亚胺的还原反应.结果表明,催化剂的催化转化率较高(80%~98%),立体选择性(e.e.值)较好,其中催化剂N2,N2'-二氧-9,9'-二甲基-3,3'-环己基甲酰胺-β-双咔啉(4B)的催化转化率达到了98%,e.e.值达68%.     

Coordination reaction of cobaloxime with 4-vinylpyridine-styrene copolymer

The equilibrium constants of the coordination reaction of chlorodimethylformamide·cobaloxime with 4-vinylpyridine–styrene copolymers (PPS) were determined. The constants for PPS, which contain 20–50% 4-vinylpyridine (4VP) unit, measured about 1.3 × 10⁵ liter/mole larger than those in the pyridine system (6.8 × 10⁴ liter/mole). When the polymer ligand is 4VP homopolymer or contains less than 20% 4VP unit, K values are lower. The rate constants (k_f) of the coordination reactions of the cobaloxime with polymer ligands were also measured in dimethylformamide (DMF) and benzene. In DMF k_f decreased with an increase in 4VP unit content of the polymer ligand; in benzene it was increased by the 4VP fraction. These results can be explained by the variation in conformation of the polymer chain in each solvent. The effect of the polymer chain on complexation was discussed on the basis of the kinetic data.     

Polymer effect in graft polymerizations of acrolein onto imidazole-containing polymer

The graft polymerizations of acrolein (AL) onto an imidazole (Im)-containing polymer, such as a homopolymer of 4(5)-vinylimidazole (VIm) and several copolymers of VIm-4-vinylpyridine (VPy), VIm-1-vinyl-2-pyrrolidone (VPr), and VIm-styrene (St), have been studied in ethanol at 0°C. The degree of polymerization (P?_n) of the resulting polyacrolein graft depended on the number of Im units in the Im-containing polymer which produced a decrease in P?_n of grafted polyacrolein. The P?_n of the graft polyacrolein was determined to be in the range of 5-23. The rate of polymerization (R_p) was expressed by R_p = k(PVIm) (AL)². The graft polymerizability of the AL was influenced by the comonomer in the parent polymer, and was found to be in the order of VIm homopolymer > VIm-VPr copolymer > VIm-VPy copolymer > VIm-St copolymer. R_p was affected by the functional group around the Im group in the Im-containing polymer. These results were discussed by assuming the conformation of the parent polymer in ethanol.     

Phenylmethoxybis(tetrazolium) ion-association complexes with an anionic indium(III) — 4-(2-pyridylazo)resorcinol chelate

Complex formation and liquid-liquid extraction were studied in systems containing indium(III), 4-(2-pyridylazo)resorcinol (PAR), phenylmethoxybis(tetrazolium) salt (MBT), water and chloroform. The following MBTs, which differ only by the number of -NO₂ groups in their cationic parts, were used: 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis(2,5-diphenyl-2H-tetrazolium chloride) (Blue Tetrazolium chloride, BT), 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride] (Nitro Blue Tetrazolium chloride, NBT) and 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2,5-di(4-nitrophenyl)-2H-tetrazolium chloride] (Tetranitro Blue Tetrazolium chloride, TNBT). The composition of the formed ternary complexes was determined, In:PAR:MBT=1:2:2, and the optimum conditions for their extraction found: pH, shaking time, concentration of the reagents and the sequence of their addition. Some key constants were estimated: constants of extraction (K_ex), constants of association (β) and constants of distribution (K_D). BT appears to be the best MBT for extraction of the In(III)-PAR species, [In³⁺(OH)₃(PAR)₂]^4?, (Log K_ex=10.9, Log β=9.8, Log K_D=1.12, R%=92.7%). Several additional characteristics concerning its application as extraction-spectrophotometric reagent were calculated: limit of detection (LOD = 0.12 μg cm^?3), limit of quantification (LOD = 0.40 μg cm^?3) and Sandell’s sensitivity (SS =1.58 ng cm^?2); Beer’s law is obeyed for In(III) concentrations up to 3.2 μg mL^?1 with a molar absorptivity coefficient of 7.3×10⁴ L mol^?1 cm^?1 at λ_max=515 nm.      

Manganese(III) acetate‐catalyzed synthesis of polyguaiacol

Polyguaiacol was synthesized in the mixtures of water and various organic solvents using manganese(III) acetate as a new catalyst for radical polymerization and a biomimetic model for manganese peroxidase. Aqueous solutions of 30–70% (v/v) acetonitrile, 1,4‐dioxane, and methanol were used as model solvent mixtures. The polymer yield in the methanol (<30%) solution was lower than that in the acetonitrile or 1,4‐dioxane solution (60–90%). The average molecular weight of the polymer was also lowest in the methanol solution. Difference UV absorption spectroscopy analysis revealed that nonhydrated guaiacol clusters were found to be dominant in acetonitrile and 1,4‐dioxane solutions, especially when the content of 1,4‐dioxane was 50% (v/v) or higher. In the methanol solution, only the hydrated guaiacol clusters were observed. From the comparison of ¹H NMR data for polyguaiacol and products of guaiacol oxidation by manganese(III) acetate, 3‐(4‐hydroxy‐3‐methoxy‐phenyl)‐5,3′‐dimethoxy‐4,4′‐biphenol and a mixture of 5‐(4‐hydroxy‐3‐methoxyphenyl)‐3,3′‐dimethoxy‐4,4′‐biphenoquinone and 3‐(4‐hydroxy‐3‐methoxyphenyl)‐5,3′‐dimethoxy‐4,4′‐biphenoquinone were found to be the major structural units of polyguaiacol. Water molecule is not involved in the formation of these compounds. Therefore, the polymerization should take place readily not in methanol but in acetonitrile and 1,4‐dioxane solutions. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6009–6015, 2008     

Synthesis and characterization of fluorinated poly(amide imide)s derived from 1,4‐bis(2′‐trifluoromethyl‐4′‐trimellitimidophenoxy)benzene and aromatic diamines

A series of fluorinated poly(amide imide)s were prepared from 1,4‐bis(2′‐trifluoromethyl‐4′‐trimellitimidophenoxy)benzene and various aromatic diamines [3,3′,5,5′‐tetramethyl‐4,4′‐diaminediphenylmethane, α,α‐bis(4‐amino‐3,5‐dimethyl phenyl)‐3′‐trifluoromethylphenylmethane, 1,4‐bis(4′‐amino‐2′‐trifluoromethylphenoxy)benzene, 4‐(3′‐trifluoromethylphenyl)‐2,6‐bis(3′‐aminophenyl)pyridine, and 1,1‐bis(4′‐aminophenyl)‐1‐(3′‐trifluoromethylphenyl)‐2,2,2‐trifluoroethane]. The fluorinated poly(amide imide)s, prepared by a one‐step polycondensation procedure, had good solubility both in strong aprotic solvents, such as N‐methyl‐2‐pyrrolidinone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, and cyclopentanone, and in common organic solvents, such as tetrahydrofuran and m‐cresol. Strong and flexible polymer films with tensile strengths of 84–99 MPa and ultimate elongation values of 6–9% were prepared by the casting of polymer solutions onto glass substrates, followed by thermal baking. The poly(amide imide) films exhibited high thermal stability, with glass‐transition temperatures of 257–266 °C and initial thermal decomposition temperatures of greater than 540 °C. The polymer films also had good dielectric properties, with dielectric constants of 3.26–3.52 and dissipation factors of 3.0–7.7 × 10^?3, and acceptable electrical insulating properties. The balance of excellent solubility and thermal stability associated with good mechanical and electrical properties made the poly(amide imide)s potential candidates for practical applications in the microelectronics industry and other related fields. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1831–1840, 2003     

Study on ketalization reaction of poly(vinyl alcohol) by ketones. IX. Kinetic study on acetalization and ketalization reaction of 1,3-butanediol as a model compound for poly(vinyl alcohol)

A kinetic study was carried out on the acetalization reaction of 1,3-butanediol, as a model compound for poly(vinyl alcohol) (PVA), in water, under acidic conditions. Since these equilibrium constants of ketalization reaction of 1,3-butanediol and ethylene glycol are so small, the kinetic parameters were estimated from the hydrolysis reactions of the corresponding ketals. It was made clear that these reactions proceed in the reversible bimolecular reaction, and the heat of reaction and activation energy are nearly equal to that of PVA. The rate constants of hydrolysis reaction (k′s) of model compounds were calculated on the basis of value of acetone ketal, Hammett-Taft's equation log k′s/k′so – 0.54(n – 6) = ρ^*σ^* was established, and the value of ρ^* was obtained (3.60), which coincided with the value of PVA. Therefore, it was made clear that the hydrolysis reactions of acetals and ketals are electrophilic reaction (SE II reaction) and the step of rate determination is the formation of hemiacetal and hemiketal. The rate constants of hydrolysis reaction of 1,3-butanediol acetals and ketals were approximately 10–20 larger, and those of ethylene glycol were approximetly 50–80 larger except for ketals, and those of ethanol were roughly 2000–10,000 larger compared with that of high-molecular weight compound (PVA). It can be well explained that these differences in the rate constant depend on their entropy and the mobility of molecules. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1719–1931, 1997     

Liquid crystallinity,IR analysis,and mechanical properties of thermotropic polyamides having alkylene spacers

Thermotropic polyamides with high molecular weights were synthesized by melt polycondensation of 3,3′-disubstituted-4,4′-biphenylenediacetamides with α,o-diphenoxyalkane-4,4′-dicarboxylic acids. Methyl, methoxy, and chloro groups were used as 3,3′-substituents. IR measurements revealed that there are hydrogen-bonded carbonyls and free carbonyls the intensities of which depended on the polymer structure and the temperature. The thermotropic liquid crystallinity of the polyamides is assumed to occur by a decrease in intermolecular hydrogen bondings between carbonyls and amide NH's which was caused both with 3,3′-substitutions of the biphenylene moiety and with introduction of long alkylene spacers in the polymer backbone. In addition, mechanical properties of the thermotropic polyamides were measured on the molded dumbbell-type specimen. The 3,3′-dichloro polyamides showed medium tensile strengths and moduli in the range of 500–890 kgf/cm²a nd 19.0 × 10³ to 27.0 × 10³ kgf/cm², respectively. © 1996 John Wiley & Sons, Inc.     

Heterogeneous catalysis by new bead‐shaped polymer‐supported multisite phase transfer catalysts

Three different new insoluble bead‐shaped polymer‐supported multisite phase transfer catalysts containing two, four and six active sites have been prepared and characterized by FTIR, TGA, [chloride ion] and SEM analyses. The presence of number of active sites in each catalyst and their corresponding catalytic ability were studied by determining pseudo‐first order rate constants for C‐alkylation of phenylacetonitrile (PAN) and four different substituted PAN as the substrate using a low concentration of NaOH (25% w/w) at 50 °C. The observed rate constants were compared with rate constants of same reactions catalyzed by single‐site catalyst under identical reaction conditions. From comparative study, the efficiency of catalysts were found to be in the order six‐site>four‐site>two‐site>single‐site thus confirming number of active sites in each catalyst. Further, the detailed kinetic profile of C‐alkylation of PAN has been investigated using the superior six‐site catalyst by varying stirring speed, [substrate], [catalyst], [NaOH], and temperature. Based on the observed kinetic and activation parameters, an interfacial mechanism was proposed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 771–785, 2009     

Kinetics and mechanism of indigo carmine-acidic iodate reaction. An indicator reaction for catalytic determination of Ru(III) ion

A kinetic study of uncatalyzed and Ru(III) catalyzed oxidation of indigo carmine(IC) (disodium 3,3′-dioxobi-indolin-2,2′-ylidene-5,5′-disulphonate) by iodate ion in aqueous sulphuric acid solution is reported. The uncatalyzed reaction order was found to be four; one each with respect to IC and iodate ion and second order with H⁺ ion. The Ru(III) catalyzed reaction was of fifth order, second order with respect to H⁺ and first order with respect to reductant, oxidant, and catalyst. Stoichiometric ratios of both reactions were the same with a 3:2 reductant-oxidant ratio. In both uncatalyzed and catalyzed reactions isatin-5-monosulphonic acid (2,3-dioxoindoline-5-sulphonic acid) was observed as the oxidation product. Rate constants for both the reactions are reported. Reaction mechanisms consistent with the experimental data are suggested. Further, a fixed time method is described for the determination of Ru(III), based on its ability to catalyze the oxidation of IC by acidic iodate. Using [H⁺] 2.25M, [iodate] 1.00 × 10^?3M and [IC] 5.0 × 10^?5M, in presence of Ru(III), the reaction followed first order kinetics with respect to IC. The interference of various cations, neutral salts, and potassium iodide on the determination of Ru(III) was studied using synthetic mixtures. The selectivity of the method and the recommended procedure are described.     

Synthesis,characterization, and kinetics studies of organic soluble photosensitive copolyimide

A copolyimide synthesized from 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, 3,5-diaminobenzoic acid, and 2,3,5,6-tetramethyl-p-phenylene diamine was found to be soluble in N-alkyl substituted amides. An organic soluble photosensitive polyimide was obtained by further reaction of the copolyimide with methacrylic acid glycidyl ester. After adding Michler's ketone, the UV spectra absorbance near 360 nm of the copolyimide decreased rapidly upon the irradiation of mercury lamp. Using benzoic acid and methacrylic acid glycidyl ester as model compounds and N, N-dimethylbenzylamine as catalyst, the mechanism of reaction between the carboxylic group of the copolyimide and epoxy group of methacrylic acid glycidyl ester in N-methyl-2-pyrrolidone was found to have two competitive reactions, namely the auto-catalytic and the catalytic reactions. The apparent rate constants of each reaction were determined. Comparison of apparent rate constants between the model compound and the polymer reaction system are also reported.     

Chiral‐Organotin‐Catalyzed Kinetic Resolution of Vicinal Amino Alcohols

A highly efficient kinetic resolution of racemic amino alcohols has been achieved for the first time with a chiral tin catalyst. A chiral organotin compound with 3,4,5‐trifluorophenyl groups at the 3,3′‐positions of the binaphthyl framework enabled this transformation with excellent yield and high enantioselectivity. The process tolerates aryl‐ and alkyl‐substituted amino alcohols and a variety of other substrates, affording the corresponding products in high enantioselectivity and with s factors up to >500.     

Electron-transfer reactions and conformational changes associated with the reduction of substituted bianthrones

The electrochemical reduction of several substituted bianthrones is similar to that of the parent compound. 3,3′-Dimethylbianthrone (II), 3,3′-di-n-heptylbianthrone (III). 3,3′-dimethoxybianthrone (IV) and 1,1′-dimethylbianthrone -(V) were studied in dimethylformamide using cyclic voltammetry and transmission mode spectroelectrochemistry. For each compound the low temperature A form is reduced in a two-electron irreversible reaction to a twisted dianion, B^2?. Upon oxidation, B^2? forms first B, then B, whose spectral properties are identical to those of the high-temperature thermochromic form of the bianthrones. Rate constants for the B-A reaction were determined for each compound. The reduction of 2,3,2′,3′-dibenzo-7,7′-dimethylbianthrone (VI) showed somewhat different features which were tentatively interpreted in terms of redox catalysis.     

Oxidation of 2,6-Di-tert-butylphenol by dioxygen catalyzed by tetrasodium phthalocyaninatocobalt(II) tetrasulfonate in aqueous micellar media

The oxidation of 2,6-di-tert-butylphenol by dioxygen has been investigated in aqueous micellar aggregates of cetyltrimethylammonium bromide (CTAB) using tetrasodium phthalocyaninatocobalt(II) tetrasulfonate (CoPcTsNa₄) as catalyst. The CTAB/CoPcTsNa4 system showed enhanced catalytic activity in the oxidation of 2,6-di-tert-butylphenol compared to that observed in the oxidation reaction in the absence of CTAB. 2,6-Di-tert-butyl-1,4-benzoquinone and 3,5,3′,5′-tetra-tert-butyl-4,4-diphenoquinone were identified as reaction products. The initial rate constants of auto-oxidation reaction was found to increase with increasing the pH range from 7.0 to 13.0. The rate constants k_obs of auto-oxidation reaction showed linear dependence on catalyst concentration. The rate of auto-oxidation reaction was found to fit a Michealis-Menten kinetic model for the saturation of catalyst sites with increasing 2,6-di-tert-butylphenol concentration and dioxygen pressure. Tetrasodium phthalocyaninatocobalt(II) tetrasulfonate in aqueous micellar solution of CTAB was found to be mainly monomeric.     

Asymmetric oxidative coupling polymerization affording polynaphthylene with 1,1′-bi-2-naphthol units

The oxidative coupling polymerizations of racemic-, (R)-, and (S)-2,2′-dimethoxymethoxy-1,1′-binaphthalene-3,3′-diols were carried out with a copper catalyst with various ligands, such as N,N,N′,N′-tetramethylethylenediamine (TMEDA), (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine, (−)-sparteine, and (S)-(−)-2,2′-isopropylidenebis(4-phenyl-2-oxazoline) [(−)-Phbox], under an O₂ atmosphere. For example, a 10/1 (v/v) MeOH · H₂O-insoluble polymer with a number-average molecular weight of 3.8 × 10³, from a polymerization with CuCl–TMEDA followed by acetylation of the hydroxyl groups, was obtained in a 71% yield. Polymerization with (−)-Phbox proceeded in an S-selective manner to give a polymer with the highest negative specific rotation from the (S)-monomer. The obtained polymer was successfully converted into a polymer with the optically pure 1,1′-bi-2-naphthol unit based on the original monomer structure, which could be used as a polymeric chiral auxiliary and showed catalytic activity for the asymmetric diethylzinc addition reaction to aldehydes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4528–4534, 2004     

Reduction of olefins,nitroarenes and Schiff base compounds by a polymer-supported [2-(2′-pyridyl)benzimidazole]palladium complex

2-(2′-Pyridyl)benzimidazole (PBIMH) was functionalized onto chloromethylated polystyrene beads crosslinked with 6.5 % divinylbenzene, and this solid support was then reacted with Na₂PdCl₄ in methanol. The functionalized beads were then activated using sodium borohydride. The resultant polymer-supported [2-(2′-pyridyl)benzimidazole]palladium complex (PSDVB–PBIM–PdCl₂) and its activated form were characterized by various physicochemical techniques. XPS studies confirmed the +2 oxidation state of palladium in the supported complex. The activated complex was found to catalyse the hydrogenation of various organic substrates including olefins, nitro and Schiff base compounds. Kinetic measurements for the hydrogenation of cyclopentene, cyclohexene and cyclooctene were carried out by varying temperature, catalyst and substrate concentration. The energy and entropy of activation were evaluated from the kinetic data. The catalyst showed an excellent recycling efficiency over six cycles without leaching of metal from the polymer support, whereas the unsupported complex was unstable as metal leached out into the solution during the first run.     

The specific feature of photochemical processes in molecules of 3,3′-dialkylthiacarbocyanines in binary solvent mixtures

The effect of the composition of the dimethyl sulfoxide (DMSO)-toluene mixture on the photochemical processes of 3,3′-diethylthiacarbocyanine (DETCC) iodide and 3,3′-dimethylthiacarbocyanine (DMTCC) chloride was studied. In the mixtures with the DMSO content more than 20 vol %, DETCC iodide and DMTCC chloride molecules are characterized by a high efficiency of both trans → cis photoisomerization and fluorescence, in contrast to intersystem crossing to the triplet state. With decreasing the DMSO content to 3 vol %, the relative quantum yield of DETCC iodide intersystem crossing increases by two orders of magnitude, which is accompanied by a decrease in the lifetime of DETCC iodide triplet molecules from 1.1 × 10^?4 to 2.4 × 10^?7 s and a decrease in the yield of the cis-isomers. To explain the results, the concepts of “external heavy atom (iodide) effect” and hyperfine coupling (HFC mechanism) in radical pairs that could be formed via electron transfer between the iodide and an excited dye molecule were used.     

Kinetics of the reaction of 4,4′‐biphenol with bromoethane and 1‐bromobutane by phase‐transfer catalysis

The reaction of 4,4′‐biphenol and two species of bromoalkanes (e.g., bromoethane and 1‐bromobutane) to synthesize two symmetric products (4,4′‐diethanoxy biphenyl and 4,4′‐dibutanoxy biphenyl) and one asymmetric product (4‐ethanoxy, 4′‐butanoxy biphenyl) was successfully carried out under two‐phase phase‐transfer catalysis conditions. A rational mechanism and kinetic model were built up by considering the reactions both in aqueous phase and in organic phase. The first active catalyst (QO(Ph)₂OQ) was also synthesized under two‐phase reaction and was identified by instruments. The experimental data were explained satisfactorily by the pseudo‐steady‐state hypothesis. Two sets of rate constants of organic reactions, i.e. primary (k₁ and k₂) and secondary (k₁₁, k₁₂, k₂₁, and k₂₂) rate constants participate in the kinetic model. The two primary rate constants were obtained individually via experimental data for synthesizing the symmetric products. The ratios of the other four secondary rate constants were obtained from the reaction of synthesizing asymmetric products and determined from the initial yield rates of symmetric products. The effects of the ratio of bromoethane and 1‐bromobutane, temperature, organic solvents, amount of catalyst, and amount of sodium hydroxide on the reaction rate and the selectivity of products were investigated in detail. The results were explained satisfactorily by the interaction between the reactants and the environmental species. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 139–153, 2003