Reactivity Sequence Research Articles

Design and Control of Reactive Distillation Sequences with Heat-Integrated Stages To Produce Diphenyl Carbonate

Reactive distillation (RD) in quaternary systems has gained importance when one of the reagents is in excess. In this work, higher energy savings in a reactive distillation sequence is addressed to produce diphenyl carbonate, which is a crucial precursor of polycarbonate. Energy savings were attained through heat integration between the high-pressure RD column and the low-pressure separation column. The design of sequences with heat-integrated stages was done by combining simulation and optimization. The sequence with one heat-integrated stage realized the minimum energy consumption with energy savings around 22% and cost savings around 12% in comparison with the conventional reactive distillation sequence. Also, two control schemes for the best design configuration have also been studied in this work. The results showed that the control scheme that manipulates the reboiler duty and reflux ratio to control two stage temperatures can provide excellent responses under throughput and feed composition disturb...

Endogenous sources of path generation in a path dependent industry

ABSTRACTThis paper investigates and conceptualises industry endogenous sources of innovation in a context of path dependency. With an embedded case study of the mature multi-technology lighting industry, it considers two cases of technology generation (fluorescent lamps and light-emitting diodes) that have occurred under the dominance of established incandescent technology. The results demonstrate the existence of common driving forces (variety of performance criteria and variety of lighting applications) behind the development of the existing path and the generation of two new paths. Such common driving forces indicate the existence of a reactive sequence or a logical causal relationship between the existing and the new paths, which serve as an enabling mechanism in endogenous path generation.

ChemInform Abstract: Scaffold Diversity Through a Branching Double‐Annulation Cascade Strategy: Iminium‐Induced One‐Pot Synthesis of Diverse Fused Tetrahydroisoquinoline Scaffolds.

A branching double-annulation cascade (BDAC) strategy for diverse and complex fused THIQ scaffolds via a highly reactive iminium-induced one-pot double-cyclization sequence involving Pictect–Spengler-type cyclization has been developed for the first time. The salient features of this protocol are that it allows direct and rapid access to unprecedented diverse fused THIQ skeletons, is metal/catalyst free, has a cleaner reaction profile, provides good to excellent yields, and is a convenient approach. This catalyst-free domino process facilitates the double annulation with a variety of scaffold building agents via two C–N and one C–X (X = C, N, O) bond formation in a single step under uniform reaction conditions. Furthermore, we reveal an unusual dual BDAC sequence leading to N–N-linked isoquinoline dimer.

Michael Addition Polymerization of Trifunctional Amine and Acrylic Monomer: A Versatile Platform for Development of Biomaterials.

Michael addition polymerizations of amines and acrylic monomers are versatile approaches to biomaterials for various applications. A combinatorial library of poly(β-amino ester)s and diverse poly(amido amine)s from diamines and diacrylates or bis(acrylamide)s have been reported, respectively. Furthermore, novel linear and hyperbranched polymers from Michael addition polymerizations of trifunctional amines and acrylic monomers significantly enrich this category of biomaterials. In this Review, we focus on the biomaterials from Michael addition polymerizations of trifunctional amines and acrylic monomers. First we discuss how the polymerization mechanisms, which are determined by the reactivity sequence of the three types of amines of trifunctional amines, i.e., secondary (2°) amines (original), primary (1°) amines, and 2° amines (formed), are affected by the chemistry of monomers, reaction temperature, and solvent. Then we update how to design and synthesize linear and hyperbranched polymers based on the understanding of polymerization mechanisms. Linear polymers containing 2° amines in the backbones can be obtained from polymerizations of diacrylates or bis(acrylamide)s with equimolar trifunctional amine, and several approaches, e.g., 2A2+BB'B″, A3+2BB'B', A2+BB'B″, to hyperbranched polymers are developed. Further through molecular design of monomers, conjugation of functional species to 2° amines in the backbones of linear polymers and the abundant terminal groups of hyperbranched polymers, the amphiphilicity of polymers can be adjusted, and additional stimuli, e.g., thermal, redox, reactive oxidation species (ROS), and light, responses can be integrated with the intrinsic pH response. Finally we discuss the applications of the polymers for gene/drug delivery and bioimaging through exploring their self-assemblies in various motifs, e.g., micelles, polyplexes particles/nanorings and hydrogels. Redox-responsive hyperbranched polymers can display 300 times higher in vitro gene transfection efficiency and provide a higher in vivo siRNA efficacy than PEI. Also redox-responsive micelle carriers can improve the efficacy of anticancer drug and the bioimaging contrast. Further molecular design and optimization of this category of polymers together with in vivo studies should provide safe and efficient biomaterials for clinical applications.

Scaffold Diversity through a Branching Double-Annulation Cascade Strategy: Iminium-Induced One-Pot Synthesis of Diverse Fused Tetrahydroisoquinoline Scaffolds.

A branching double-annulation cascade (BDAC) strategy for diverse and complex fused THIQ scaffolds via a highly reactive iminium-induced one-pot double-cyclization sequence involving Pictect-Spengler-type cyclization has been developed for the first time. The salient features of this protocol are that it allows direct and rapid access to unprecedented diverse fused THIQ skeletons, is metal/catalyst free, has a cleaner reaction profile, provides good to excellent yields, and is a convenient approach. This catalyst-free domino process facilitates the double annulation with a variety of scaffold building agents via two C-N and one C-X (X = C, N, O) bond formation in a single step under uniform reaction conditions. Furthermore, we reveal an unusual dual BDAC sequence leading to N-N-linked isoquinoline dimer.

Mimicking the Main Events of the Biosynthesis of Drimentines: Synthesis of Δ8′‐Isodrimentine A and Related Compounds

Drimentines are a family of tetracyclic alkaloids biosynthetically originating from the condensation of sesquiterpene units onto cyclic dipeptides. A straightforward assembly of the fused “pyrroloindoline–diketopiperazine” core of drimentines is described herein and used for the synthesis of Δ8′‐isodrimentine A. The strategy involves a bio‐inspired indole dearomatization of a tryptophan‐containing cyclodipeptide by a drimane‐type decaline followed by the intramolecular trapping of the resulting indolenine intermediate in an uninterrupted reactive sequence. The starting diketopiperazine was prepared by classical peptidic coupling and the drimane‐type decaline from (+)‐sclareolide. A fully biomimetic approach with a linear sesquiterpene unit is also reported and led to farnesylated pyrroloindoline–diketopiperazines, which correspond to the proposed biosynthetic precursors of both drimentines A and D. The end product Δ8′‐isodrimentine A and its congeners were evaluated in vitro for their cytotoxic activities against three human tumor cell lines.

Taurine Bromamine: Reactivity of an Endogenous and Exogenous Anti-Inflammatory and Antimicrobial Amino Acid Derivative.

Taurine bromamine (Tau-NHBr) is produced by the reaction between hypobromous acid (HOBr) and the amino acid taurine. There are increasing number of applications of Tau-NHBr as an anti-inflammatory and microbicidal drug for topical usage. Here, we performed a comprehensive study of the chemical reactivity of Tau-NHBr with endogenous and non-endogenous compounds. Tau-NHBr reactivity was compared with HOBr, hypochlorous acid (HOCl) and taurine chloramine (Tau-NHCl). The second-order rate constants (k2) for the reactions between Tau-NHBr and tryptophan (7.7 × 102 M−1s−1), melatonin (7.3 × 103 M−1s−1), serotonin (2.9 × 103 M−1s−1), dansylglycine (9.5 × 101 M−1s−1), tetramethylbenzidine (6.4 × 102 M−1s−1) and H2O2 (3.9 × M−1s−1) were obtained. Tau-NHBr demonstrated the following selectivity regarding its reactivity with free amino acids: tryptophan > cysteine ~ methionine > tyrosine. The reactivity of Tau-NHBr was strongly affected by the pH of the medium (for instance with dansylglycine: pH 5.0, 1.1 × 104 M−1s−1, pH 7.0, 9.5 × 10 M−1s−1 and pH 9.0, 1.7 × 10 M−1s−1), a property that is related to the formation of the dibromamine form at acidic pH (Tau-NBr2). The formation of singlet oxygen was observed in the reaction between Tau-NHBr and H2O2. Tau-NHBr was also able to react with linoleic acid, but with low efficiency compared with HOBr and HOCl. Compared with HOBr, Tau-NHBr was not able to react with nucleosides. In conclusion, the following reactivity sequence was established: HOBr > HOCl > Tau-NHBr > Tau-NHCl. These findings can be very helpful for researchers interested in biological applications of taurine haloamines.

Detection of intra-brain cytoplasmic 1 (BC1) long noncoding RNA using graphene oxide-fluorescence beacon detector.

Detection of cellular expression of long noncoding RNAs (lncRNAs) was elusive due to the ambiguity of exposure of their reactive sequences associated with their secondary/tertiary structures and dynamic binding of proteins around lncRNAs. Herein, we developed graphene-based detection techniques exploiting the quenching capability of graphene oxide (GO) flakes for fluorescent dye (FAM)-labeled single-stranded siRNAs and consequent un-quenching by their detachment from GO by matching lncRNAs. A brain cytoplasmic 1 (BC1) lncRNA expression was significantly decreased by a siRNA, siBC1–1. GO quenched the FAM-labeled siBC1–1 peptide nucleic acid (PNA) probe, and this quenching was recovered by BC1. While FAM-siBC1–1-PNA-GO complex transfected spontaneously mouse or human neural stem cells, fluorescence was recovered only in mouse cells having high BC1 expression. Fluorescent dye-labeled single-stranded RNA-GO probe could detect the reactive exposed nucleic acid sequence of a cytoplasmic lncRNA expressing in the cytoplasm, which strategy can be used as a detection method of lncRNA expression.

Identification of Sequence Specificity of 5-Methylcytosine Oxidation by Tet1 Protein with High-Throughput Sequencing.

Tet (ten-eleven translocation) family proteins have the ability to oxidize 5-methylcytosine (mC) to 5-hydroxymethylcytosine (hmC), 5-formylcytosine (fC), and 5-carboxycytosine (caC). However, the oxidation reaction of Tet is not understood completely. Evaluation of genomic-level epigenetic changes by Tet protein requires unbiased identification of the highly selective oxidation sites. In this study, we used high-throughput sequencing to investigate the sequence specificity of mC oxidation by Tet1. A 6.6×10(4) -member mC-containing random DNA-sequence library was constructed. The library was subjected to Tet-reactive pulldown followed by high-throughput sequencing. Analysis of the obtained sequence data identified the Tet1-reactive sequences. We identified mCpG as a highly reactive sequence of Tet1 protein.

Synergistic catalytic activity of RuCl3 and OsO4 on the selective oxidation of pregabalin drug molecule: Exploration of scope, reaction mechanism and kinetic modeling

The kinetics and mechanism of (RuCl3+OsO4) in combination and, RuCl3 and OsO4 alone catalyzed oxidation of pregabalin (PGB) drug with chloramine-T have been investigated at 313K in aqueous alkaline medium. The kinetic characteristics were found to be varied for each catalyzed reactions. In all the three catalyzed reactions, the reaction rate shows a first-order dependence of rate on [CAT]0 and a negative-fractional-order on [NaOH]. The order of [PGB]0 is found to be unity incase of [OsO4], but it is fractional in both RuCl3 and [RuCl3+OsO4] catalyzed reactions. The orders with respect to [RuCl3] and [OsO4] are less than one whereas it is unity in case of [RuCl3+OsO4]. Activation parameters have been evaluated. 2-isobutylsuccinic acid was identified as the oxidation product of PGB. Under identical set of experimental conditions, the reaction rates revealed that all the three catalyzed reactions are about 25 to 71-fold faster than the uncatalyzed reactions. The catalytic efficiency of these catalysts follows the order (RuCl3+OsO4)>OsO4>RuCl3. The observed reactivity sequence may be attributed to the different d-electronic configuration of the catalysts. Most noteworthy is the significant catalytic activity of 71-fold in case of (RuCl3+OsO4) catalyst. It justifies the synergistic effect of (RuCl3+OsO4) catalyst on the oxidation of PGB drug. An isokinetic relationship is observed with β=366K, indicating that enthalpy factors are controlling the rate. The reaction mechanisms put forward and rigorous kinetic models deduced, give the best fit to the experimental results for each catalyzed reactions.

Reactive symbol sequences for a model of hydrogen combustion.

Transient, macroscopic states of chemical disequilibrium are born out of the microscopic dynamics of molecules. As a reaction mixture evolves, the temporal patterns of chemical species encodes some of this dynamical information, while their statistics are a manifestation of the bulk kinetics. Here, we define a chemically-informed symbolic dynamics as a coarse-grained representation of classical molecular dynamics, and analyze the sequences of chemical species for a model of hydrogen combustion. We use reactive molecular dynamics simulations to generate the sequences and derive probability distributions for sequence observables: the reaction time scales and the chain length - the total number of reactions between initiation of a reactant and termination at products. The time scales and likelihood of the sequences depend strongly on the chain length, temperature, and density. Temperature suppresses the uncertainty in chain length for hydrogen sequences, but enhances the uncertainty in oxygen sequence chain lengths. This method of analyzing a surrogate chemical symbolic dynamics reduces the complexity of the chemistry from the atomistic to the molecular level and has the potential for extension to more complicated reaction systems.

Identification and molecular characterization of oat peptides implicated on coeliac immune response

BackgroundOats provide important nutritional and pharmacological properties, although their safety in coeliac patients remains controversial. Previous studies have confirmed that the reactivity of the anti-33-mer monoclonal antibody with different oat varieties is proportional to the immune responses in terms of T-cell proliferation. Although the impact of these varieties on the adaptive response has been studied, the role of the dendritic cells (DC) is still poorly understood. The aim of this study is to characterize different oat fractions and to study their effect on DC from coeliac patients.Methods and resultsProtein fractions were isolated from oat grains and analyzed by SDS–PAGE. Several proteins were characterized in the prolamin fraction using immunological and proteomic tools, and by Nano-LC-MS/MS. These proteins, analogous to α- and γ-gliadin-like, showed reactive sequences to anti-33-mer antibody suggesting their immunogenic potential. That was further confirmed as some of the newly identified oat peptides had a differential stimulatory capacity on circulating DC from coeliac patients compared with healthy controls.ConclusionsThis is the first time, to our knowledge, where newly identified oat peptides have been shown to elicit a differential stimulatory capacity on circulating DC obtained from coeliac patients, potentially identifying immunogenic properties of these oat peptides.

Assessment of Sites of Marrow and Extramedullary Hematopoieis By Hybrid Imaging in Patients with Primary Myelofibrosis

BACKGROUNDThe dynamic relationship between HSC, their niches and the trabecular bone is disrupted in MPN as primary myelofibrosis (PMF).PMF is associated to extramedullary hematopoiesis (EMH) usually with splenomegaly. Several tracers are used in nuclear medicine to assess EMH and bone marrow (BM) activity. Colloids labelled with Technetium 99m (99mTc) show the reticulo-endothelial system (RES) and Indium111 chloride (111In-Cl3) transferrin scintigraphy reflects the hematopoietic activity. Cell imaging using single photon emission tomography (SPECT) utilizes gamma emitting radiopharmaceuticals and 3D acquisition allowing for imaging planes reconstruction. It is often coupled to a computed tomography (CT) (SPECT/CT).Few data exist about hematopoiesis assessment in PMF using hybrid imaging (HIm). We have shown its interest in EMH diagnosis. In PMF, we looked at patterns of active/inactive hematopoiesis in order to study later the impact of targeted therapies.MATERIAL & METHODSWe performed HIm with 99mTc nanocolloids and 111In-Cl3 (coupled to SPECT/CT) in 5 untreated PMF patients and in 1 with essential thrombocytemia (ET) who was developing a secondary MF (Table1).RESULTS AND DISCUSSIONWe observed a lower fixation of both tracers in the axial skeleton (AxS) and conversely a hyperfixation of 111In-Cl3 in the distal skeleton (DiS) and the spleen, this latter considered as pathognomonic of PMF or secondary MF (Figs1-2. Table1). The more advanced the process of marrow fibrosis and HSC externalization the more 111In-Cl3 splenic and DiS fixation. When associated to a low 111In-Cl3 fixation in the AxS it is suggestive of PMF. No other EMH localizations besides spleen were observed. Liver fixation interpretation was uneasy because both tracers show a significant fixation. Some questions remain unsolved as the mechanisms involved in the DiS recruitment in circumstances that this hematopoietic area was progressively inactive since birth and replaced with adipose tissue. Is DiS reactivation a consequence of HSCs that cannot seed in the physiological homing hematopoietic areas, which take part essentially in the AxS? Or is the fruit of HSC reactivation (and their microenvironment) already present in the DiS but simply dormant? In this latter case we do not know if HSCs carry the same molecular abnormalities of the malignant PMF clone.Interestingly in the post ET MF patient, there was no 111In-Cl3 hyperfixation at the DiS. Conversely we observed a significant splenic fixation with both tracers and a low fixation with 99mTc in the AxS (Figs1-2). This evocates a sequence of hematopoietic reactivation starting in the spleen, followed by DiS recruitment and associated to a progressive hematopoietic regression in the AxS. HiM using these 2 radionuclides and SPECT/CT is a non-invasive procedure allowing larger and more precise visualization of the active/inactive hematopoietic areas in PMF. Moreover, regarding deep regions or high-weight patients, attenuation correction can show more uptake focus, potentially hidden because of soft-tissue interposition between emitting source and detector. This can represent an alternative to BM biopsies that also have the inconvenient to be limited in their investigation to the crista iliac. They may reflect the AxS but do not give any information neither on DiS nor on liver and spleen hematopoiesis.CONCLUSIONSThe use of HIm allowed a good assessment of the extent and intensity of PMF hematopoiesis. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A unique serpin P1' glutamate and a conserved β-sheet C arginine are key residues for activity, protease recognition and stability of serpinA12 (vaspin).

SerpinA12 (vaspin) is thought to be mainly expressed in adipose tissue and has multiple beneficial effects on metabolic, inflammatory and atherogenic processes related to obesity. KLK7 (kallikrein 7) is the only known protease target of vaspin to date and is inhibited with a moderate inhibition rate. In the crystal structure, the cleavage site (P1-P1') of the vaspin reactive centre loop is fairly rigid compared with the flexible residues before P2, possibly supported by an ionic interaction of P1' glutamate (Glu(379)) with an arginine residue (Arg(302)) of the β-sheet C. A P1' glutamate seems highly unusual and unfavourable for the protease KLK7. We characterized vaspin mutants to investigate the roles of these two residues in protease inhibition and recognition by vaspin. Reactive centre loop mutations changing the P1' residue or altering the reactive centre loop conformation significantly increased inhibition parameters, whereas removal of the positive charge within β-sheet C impeded the serpin-protease interaction. Arg(302) is a crucial contact to enable vaspin recognition by KLK7 and it supports moderate inhibition of the serpin despite the presence of the detrimental P1' Glu(379), which clearly represents a major limiting factor for vaspin-inhibitory activity. We also show that the vaspin-inhibition rate for KLK7 can be modestly increased by heparin and demonstrate that vaspin is a heparin-binding serpin. Noteworthily, we observed vaspin as a remarkably thermostable serpin and found that Glu(379) and Arg(302) influence heat-induced polymerization. These structural and functional results reveal the mechanistic basis of how reactive centre loop sequence and exosite interaction in vaspin enable KLK7 recognition and regulate protease inhibition as well as stability of this adipose tissue-derived serpin.

Intrinsic catalytic properties of extruded clay honeycomb monolith toward complete oxidation of air pollutants

The present work highlights the intrinsic catalytic properties of extruded clay honeycomb monolith toward complete oxidation of various air pollutants namely CO, methane, propane, acetylene, propene, n-butene, methanol, ethanol, n-propanol, n-butanol, acetone, dimethyl ether, benzene, toluene, o-xylene, monochlorobenzene and 1,2-dichlorobenzene. Total catalytic conversion was achieved for all tested compounds with different behaviors depending on pollutants’ structural and chemical nature. The comparison of T50 values obtained from light-off curves allowed the establishment of the following reactivity sequence: ketone>alcohol>ether>CO>alkyne>aromatic>alkene>chlorinated aromatic>alkane. The intrinsic catalytic performances of the natural clay was ascribed to the implication of a quite complex mixture constituted by OH groups (Brønsted acids) and coordinately-unsaturated cations, such as Al3+, Fe3+ and Fe2+ (Lewis acids). Hence, the combination of the clay’s intrinsic catalytic performances and easier extrudability suggests a promissory potential for application in air pollution control.

Changing course in Latin America: party systems in the neoliberal era

1. Introduction: party system change in the neoliberal era Part I. Explaining Regional Patterns: 2. Partisanship and the puzzle of party system stability 3. Critical junctures and party system change 4. Antecedent conditions: party system differentiation in twentieth-century Latin America 5. Neoliberal critical junctures and party system stability 6. Programmatic (de-)alignment and party system stability in the aftermath period Part II. National Experiences in Comparative Perspective: 7. Critical junctures in elitist party systems 8. Critical junctures in labor-mobilizing party systems 9. Aftermath: reactive sequences and institutional legacies 10. Conclusion: political legacies and the crisis of representation Appendix: election results in Latin America.

Flavonoids in Microheterogeneous Media, Relationship between Their Relative Location and Their Reactivity towards Singlet Oxygen.

In this work, the relationship between the molecular structure of three flavonoids (kaempferol, quercetin and morin), their relative location in microheterogeneous media (liposomes and erythrocyte membranes) and their reactivity against singlet oxygen was studied. The changes observed in membrane fluidity induced by the presence of these flavonoids and the influence of their lipophilicity/hydrophilicity on the antioxidant activity in lipid membranes were evaluated by means of fluorescent probes such as Laurdan and diphenylhexatriene (DPH). The small differences observed for the value of generalized polarization of Laurdan (GP) curves in function of the concentration of flavonoids, indicate that these three compounds promote similar alterations in liposomes and erythrocyte membranes. In addition, these compounds do not produce changes in fluorescence anisotropy of DPH, discarding their location in deeper regions of the lipid bilayer. The determined chemical reactivity sequence is similar in all the studied media (kaempferol < quercetin < morin). Morin is approximately 10 times more reactive than quercetin and 20 to 30 times greater than kaempferol, depending on the medium.

Investigations on the Structure and Properties of Neutral Polymer Bonding Agents (NPBA) Used for Composite Solid Propellant. I: Study of the Reactivity Ratios and Sequence Structure Control of Acrylonitrile (AN)/Methacrylate (MA)/Hydroxyethyl Acrylate (HEA) Terpolymer Type NPBA

The copolymerization activity and sequence structure of the typical neutral polymer bonding agent (NPBA) for improving the mechanical properties of a composite solid propellant plasticized by nitrate ester were investigated. The reactivity ratios of three monomers were calculated and compared. In addition, by using Monte Carlo simulation, the effects of the monomers’ feed amount on composition and sequence structure of the copolymer were also investigated and discussed. The prepared NPBA bonding agents were used in a propellant. It was found that the results of the mechanical properties tests have good correspondence with the data of reactivity ratios and Monte Carlo simulation.

The isothermal studies of char-CO2 gasification using the high-pressure thermo-gravimetric method

The char-CO2 gasification reactions in isothermal and pressurized conditions were studied kinetically by high-pressure thermo-gravimetric analyzer, and the primary objective of this paper was to study the effects of pressure, temperature and char rank on the intrinsic reaction kinetics of the char-CO2 gasification by the Langmuir–Hinshelwood model. The results indicated that the order of reactivity sequence at the same temperature and pressure was Char A > Char B > Char C (Char A from subbituminous coal, and Char B and C from bituminous coals). With the increase in the pressure and temperature, both the intrinsic reaction rate at the same carbon conversion and the carbon conversion efficiency at the same reaction time increased. The results also showed that the gasification rate experienced an initially slow increase, followed by a rapid increase, and finally a decrease corresponding to the increase in the carbon conversion efficiency. It implied that the Langmuir–Hinshelwood model was incompatible to thorough presentation of the complete conversion of the char-CO2 gasification, but was well agreeable to the intrinsic reaction kinetics of char-CO2 gasification when the carbon conversion efficiency was low at the initial stage of the carbon conversion (0–0.6). Based on this, the intrinsic reaction kinetic models of the selected char samples were built.

Reaction Kinetics of Ozone with Selected Pharmaceuticals and Their Removal Potential from a Secondary Treated Municipal Wastewater Effluent in the Great Lakes Basin

Oxidation kinetics of selected pharmaceutical compounds and their degradation during ozonation of secondary treated municipal wastewater effluent (MWWE) was investigated. The apparent second-order rate constants for the reaction between chlorotetracycline (CTC), enrofloxacin (ENR), gemfibrozil (GEM) and ozone ranged between 6.82 – 52.7 × 104 M−1s−1. The measured second-order hydroxyl radical rate constants were several orders of magnitude higher at 8.4 × 109 – 13.1 × 109 M−1s−1 with a reactivity sequence of GEM > CTC > ENR. Overall degradation of CTC, ENR and GEM in secondary treated municipal wastewater effluent was >76 % at ozone doses of 0.33 mg O3/mg DOC or higher.