Showing papers on "Tetrahydrofuran published in 2006"
TL;DR: In the presence of an iridium pincer complex, dehydrogenation of ammonia borane (H3NBH3) occurs rapidly at room temperature in tetrahydrofuran to generate 1.0 equivalent of H2 and [NH2BH2]5.
Abstract: In the presence of an iridium pincer complex, dehydrogenation of ammonia borane (H3NBH3) occurs rapidly at room temperature in tetrahydrofuran to generate 1.0 equivalent of H2 and [NH2BH2]5. A metal borohydride complex has been isolated as a dormant form of the catalyst which can be reactivated by reaction with H2.
571 citations
TL;DR: In this paper, the reactivity of furfural and its reaction intermediates is separately investigated in a fixed-bed reactor over a commercial catalyst (C 1 : Cu/Cr/Ni/Zn/Fe = 43:45:8:3:1, atomic ratio) and a self-made multicomponent one.
Abstract: The reactivity of furfural and its reaction intermediates is separately investigated in a fixed-bed reactor over a commercial catalyst (C 1 : Cu/Zn/Al/Ca/Na = 59:33:6:1:1, atomic ratio) and a self-made multicomponent one (C 2 : Cu/Cr/Ni/Zn/Fe = 43:45:8:3:1, atomic ratio). Some interesting results are obtained in this work. Firstly, both furfural and furfuryl alcohol can eliminate carbon monoxide to produce furan. Secondly, tetrahydrofuran and 2-methyltetrahydrofuran are all very stable, and n -butanol mainly derives from furan rather than tetrahydrofuran. Thirdly, 2-pentanone, 2-methyltetrahydrofuran, 1-pentanol and 2-pentanol are all the hydrogenation products of 2-methylfuran. Finally, with C 2 catalyst containing the Ni element, the main reaction product of tetrahydrofurfuryl alcohol is tetrahydofuran, while δ-valerolactone is the main product with C 1 one. This work has unified some conflicting mechanisms and discussed the origin of some interesting products, which is important to understand the mechanism and reaction pathway of furfural hydrogenation, and to provide an instruction for the design of new catalytic formulations.
256 citations
153 citations
TL;DR: On the basis of both experimental data and theoretical calculations (DFT), a complete catalytic cycle for the isomerization of 2-propen-1-ol into propenal is described and predicted to be strongly exergonic, in full agreement with the high yields experimentally observed.
Abstract: The catalytic activity of the bis(allyl)−ruthenium(IV) dimer [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) (1), and that of its mononuclear derivatives [Ru(η3:η3-C10H16)Cl2(L)] (L = CO, PR3, CNR, NCR) (2) and [Ru(η3:η3-C10H16)Cl(NCMe)2][SbF6] (3), in the redox isomerization of allylic alcohols into carbonyl compounds, both in tetrahydrofuran and in water, is reported. In particular, a variety of allylic alcohols have been quantitatively isomerized using [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2] (1) as catalyst, the reactions proceeding in all cases faster in water. Remarkably, complex 1 has been found to be the most efficient catalyst reported to date for this particular transformation, leading to TOF and TON values up to 62 500 h-1 and 1 500 000, respectively. Moreover, catalyst 1 can be recycled and is capable of performing allylic alcohol isomerizations even in the presence of conjugated dienes, which are known to be strong poisons in isomerization catalysis. On the basis of both exp...
146 citations
TL;DR: The U(III) mixed-sandwich compound [U(eta-C5Me4H) as discussed by the authors, which contains a bridging squarate unit derived from reductive cyclotetramerization of CO, is exothermic by 136 kJ mol-1.
Abstract: The U(III) mixed-sandwich compound [U(eta-C5Me4H)(eta-C8H6{SiiPr3-1,4}2)(THF)] 1 may be prepared by sequential reaction of UI3 with K[C5Me4H] in THF followed by K2[C8H6{SiiPr3-1,4}2]. 1 reacts with carbon monoxide at -30 degrees C and 1 bar pressure in toluene solution to afford the crystallographically characterized dimer [(U(eta-C8H6{SiiPr3-1,4}2)(eta-C5Me4H)]2(mu-eta2: eta2-C4O4) 2, which contains a bridging squarate unit derived from reductive cyclotetramerization of CO. DFT computational studies indicate that addition of a 4th molecule of CO to the model deltate complex [U(eta-COT)(eta-Cp)]2(mu-eta1: eta2-C3O3)] to form the squarate complex [U(eta-COT)(eta-Cp)]2(mu-eta2: eta2-C4O4)] is exothermic by 136 kJ mol-1.
137 citations
TL;DR: The time-space average filling of hydrogen molecules in a binary tetrahydrofuran (THF)-d(8) + D(2) sII clathrate hydrate using high resolution neutron diffraction is determined and helps explain discrepancies about the hydrogen occupancy in the THF binary hydrate system.
Abstract: We have determined the time-space average filling of hydrogen molecules in a binary tetrahydrofuran (THF)-d8 + D2 sII clathrate hydrate using high resolution neutron diffraction. The filling of hydrogen in the lattice of a THF-d8 clathrate hydrate occurred upon pressurization. The hydrogen molecules were localized in the small dodecahedral cavities at 20 K, with nuclear density from the hydrogen approximately spherically distributed and centered in the small cavity. With a formation pressure of 70 MPa, molecular hydrogen was found to only singly occupy the sII small cavity. This result helps explain discrepancies about the hydrogen occupancy in the THF binary hydrate system.
117 citations
TL;DR: The results support the picture that in DNA the sugar moiety itself is an active part in the initial molecular processes leading to single strand breaks and demonstrate that THF cannot be used as surrogate to model deoxyribose in DNA with respect to the attack of electrons at subexcitation energies (<3 eV.
Abstract: We study dissociative electron attachment to furan (FN) (C4H4O), tetrahydrofuran (THF) (C4H8O), and fructose (FRU) (C6H12O6) using crossed electron/molecular beams experiments with mass spectrometric detection of the anions. We find that FN and THF are weak electron scavengers and subjected to dissociative electron attachment essentially in the energy range above 5.5eV via core excited resonances. In striking contrast to that, FRU is very sensitive towards low energy electrons generating a variety of fragment ions via a pronounced low energy feature close to 0eV. These reactions are associated with the degradation of the ring structure and demonstrate that THF cannot be used as surrogate to model deoxyribose in DNA with respect to the attack of electrons at subexcitation energies (<3eV). The results support the picture that in DNA the sugar moiety itself is an active part in the initial molecular processes leading to single strand breaks.
117 citations
TL;DR: This work indicates that the relatively high native concentration of + (large KW), which has commonly been thought to lead to the occurrence of acid-catalyzed reactions in HTW without added catalyst, does not explain the dehydration of 1,4-butanediol inHTW without catalyst, and H2O serves directly as the proton donor for the reaction.
Abstract: We conducted an experimental investigation into the kinetics and mechanism of tetrahydrofuran synthesis from 1,4-butanediol via dehydration in high-temperature liquid water (HTW) without added catalyst at 200-350 degrees C. The reaction was reversible, with tetrahydrofuran being produced at an equilibrium yield of 84% (at 200 degrees C) to 94% (at 350 degrees C). The addition of CO2 to the reaction mixture increased the reaction rate by a factor of 1.9-2.9, because of the increase in acidity resulting from the formation and dissociation of carbonic acid. This increase was much less than that expected (factor of 37-60) from a previously suggested acid-catalyzed mechanism. This disagreement prompted experiments with added acid (HCl) and base (NaOH) to investigate the influence of pH on the reaction rate. These experiments revealed three distinct regions of pH dependence. At high and low pH, the dehydration rate increased with increasing acidity. At near-neutral pH, however, the rate was essentially insensitive to changes in pH. This behavior is consistent with a mechanism where H2O, in addition to H+, serves as a proton donor. This work indicates that the relatively high native concentration of + (large KW), which has commonly been thought to lead to the occurrence of acid-catalyzed reactions in HTW without added catalyst, does not explain the dehydration of 1,4-butanediol in HTW without catalyst. Rather, H2O serves directly as the proton donor for the reaction.
109 citations
103 citations
TL;DR: Sterically demanding secondary phosphines and phosphides react with (THF)B(C(6)F(5))(3) to give the THF ring-opened compounds.
Abstract: Sterically demanding secondary phosphines and phosphides react with (THF)B(C6F5)3 (THF = tetrahydrofuran) to give the THF ring-opened compounds [R2PHC4H8OB(C6F5)3] and [Mes2PC4H8OB(C6F5)3Li(THF)2] (Mes = C6H2Me-2,4,6). These reactions also occur consecutively to give the double THF ring-opened compounds [Mes2P(C4H8OB(C6F5)3)2][Li(THF)4] and [t-Bu2P(C4H8OB(C6F5)3)2Li].
102 citations
TL;DR: The structural results suggest that the high fluoride affinity displayed by 2 results, at least in part, from the relief of steric repulsions induced by fluoride binding.
Abstract: The reaction of 10-bromo-9-oxa-10-boraanthracene with the tetrakis(tetrahydrofuran)lithium salt of dimesityl-1,8-naphthalenediylborate in diethyl ether affords 1-(dimesitylboryl)-8-(10‘-bora-9‘-oxaanthryl)naphthalene (2). This diborane reacts with [Me3SiF2][S(NMe2)3)] to afford the anionic complex [2-μ2-F]-, which has been isolated as a [S(NMe2)3]+ salt. The cyclic voltammograms of diborane 2 as well as 1-(dimesitylboryl)-8-(10‘-bora-9‘-thiaanthryl)naphthalene (1) exhibit two reversible reductions at E1/2 = −2.200 and −2.566 V (vs FcH/FcH+) for 1 and E1/2 = −2.248 and −2.620 V (vs FcH/FcH+) for 2 corresponding to the sequential reduction of the two boron centers. These two waves simultaneously disappear upon fluoride addition, thus indicating the formation of fluoride chelate complexes [1-μ2-F]- and [2-μ2-F]-. To identify the origin of the high fluoride affinity displayed by these diboranes, the structures of 2 and [2-μ2-F]- have been studied experimentally and computationally. The crystallographic studie...
TL;DR: A detailed mechanistic investigation of epoxide carbonylation by the catalyst [(salph)Al(THF)2]+ [Co(CO)4]- (1, salph = N,N'-o-phenylenebis(3,5-di-tert-butylsalicylideneimine), THF = tetrahydrofuran) is reported.
Abstract: A detailed mechanistic investigation of epoxide carbonylation by the catalyst [(salph)Al(THF)2]+ [Co(CO)4]- (1, salph = N,N‘-o-phenylenebis(3,5-di-tert-butylsalicylideneimine), THF = tetrahydrofuran) is reported. When the carbonylation of 1,2-epoxybutane (EB) to β-valerolactone is performed in 1,2-dimethoxyethane solution, the reaction rate is independent of the epoxide concentration and the carbon monoxide pressure but first order in 1. The rate of lactone formation varies considerably in different solvents and depends primarily on the coordinating ability of the solvent. In mixtures of THF and cis/trans-2,5-dimethyltetrahydrofuran, the reaction is first order in THF. From spectroscopic and kinetic data, the catalyst resting state was assigned to be the neutral (β-aluminoxy)acylcobalt species (salph)AlOCH(Et)CH2COCo(CO)4 (3a), which was successfully trapped with isocyanates. As the formation of 3a from EB, CO, and 1 is rapid, lactone ring closing is rate-determining. The favorable impact of donating solv...
TL;DR: Analysis to the level of the orientational correlation functions shows that the liquid displays a preference for T-like configurations between the tetrahydrofuran molecules, a local structure that results in void-like regions of approximately 1.25 angstroms radius within the bulk liquid.
Abstract: Hydrogen/deuterium isotopic substitution neutron diffraction techniques have been used to measure the structural correlation functions of liquid tetrahydrofuran at room temperature. Empirical potential structure refinement (EPSR) has been used to build a three-dimensional model of the liquid structure that is consistent with the experimental data. Analysis to the level of the orientational correlation functions shows that the liquid displays a preference for T-like configurations between the tetrahydrofuran molecules, a local structure that results in voidlike regions of approximately 1.25 A radius within the bulk liquid. The surface chemistry of these voids suggests a slightly positive electrostatic character. These findings are consistent with the known propensity of the liquid to solvate free electrons.
TL;DR: In this paper, the lowest three-phase equilibrium pressure was obtained under the condition that the mole fraction of tetrahydrofuran in water is 0.056 and the Raman spectroscopy results showed that the H2 and CO2 molecules competitively occupied the S-cage of structure-II.
Abstract: Isothermal phase equilibria (pressure−composition in the gas phase) for the quaternary system of H2 + CO2 + tetrahydrofuran + water have been measured in the presence of gas hydrate phase. The lowest three-phase equilibrium pressure is obtained under the condition that the mole fraction of tetrahydrofuran in water is 0.056. The Raman spectroscopy results show that the H2 and CO2 molecules competitively occupy the S-cage of structure-II (i.e., the H2 molecule is enclathrated in the hydrate cages with a small amount of tetrahydrofuran at considerably low pressure).
TL;DR: In this paper, the authors used polyvinylpyrrolidone (PVP) and chitosan (CS) membranes for de- dehydrating tetrahydrofuran (THF) from its aqueous mixtures.
TL;DR: Evidence was shown that alloying Pd with Au in bimetallic colloids leads to enhanced activity and most importantly to improved selectivity and the combination of the two metals resulted in catalysts that were very stable against poisoning, as was evidenced for the hydrogenation of styrene in the presence of thiophene.
Abstract: Colloids embedded in a silica sol-gel matrix were prepared by using fully alloyed Pd-Au colloids, and pure Pd and Au colloids stabilized with tetraalkylammonium bromide following a modified sol-gel procedure with tetrahydrofuran (THF) as the solvent. Tetraethoxysilicate (TEOS) was used as the precursor for the silica support. The molar composition of the sol was TEOS/THF/H 2 O/HCl = 1:3.5:4:0.05 for the bimetallic Pd-Au and TEOS/THF/ H 2 O/HCl=1:4.5:4:0.02 for Pd and Au monometallic systems. After refluxing, the colloid was added as a 4.5 wt % solution in THF for Pd-Au, 10.2 wt % solution in THF for Pd and 8.4 wt% solution in THF for Au at room temperature. The gelation was carried out with vigorous stirring (4 days) under an Ar atmosphere. Following these procedures, bimetallic Pd-Au-SiO 2 catalysts with 0.6 and 1 wt % metal, and monometallic Pd- and Au-SiO 2 catalysts with 1 wt % metal were prepared. These materials were further treated following four different routes: 1) by simple drying, 2) in which the dried catalysts were calcined in air at 723 K and then reduced at the same temperature, 3) in which they were directly reduced in hydrogen at 723 K, and 4) in which the surfactant was extracted using an ethanol-heptane azeotropic mixture. The catalysts were characterized by nitrogen adsorption-desorption isotherms at 77 K, H 2 chemisorption measurements, solid-state 1 H, 13 C, 29 Si-CP/MAS-NMR spectroscopy, powder X-ray diffraction (XRD), small angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and 197 Au Mossbauer spectroscopy. The physical characterization by a combination of these techniques has shown that the size and the structural characteristics of the Pd-Au colloid precursor are preserved when embedded in an SiO 2 matrix. Catalytic tests were carried out in selective hydrogenation of 3-hexyn1-ol, cinnamaldehyde, and styrene. These data showed evidence that alloying Pd with Au in bimetallic colloids leads to enhanced activity and most importantly to improved selectivity. Also, the combination of the two metals resulted in catalysts that were very stable against poisoning, as was evidenced for the hydrogenation of styrene in the presence of thiophene.
TL;DR: A scale of absolute acidity in tetrahydrofuran has been established, which has allowed calculation of the absolute pKa values of 77 bases from literature relative pK(a) data.
Abstract: The acidity constants (pKa) of 11 bases (amines, anilines, pyridines, pyrrolidines, and iminophosphoranes) have been determined in tetrahydrofuran by potentiometry, complemented by conductometric measurements. The pK(a) values of the studied bases cover a wide absolute pH range of acidity in tetrahydrofuran, from 7.4 to 21.7. From the pK(a) values obtained, a scale of absolute acidity in tetrahydrofuran has been established, which has allowed calculation of the absolute pKa values of 77 bases from literature relative pK(a) data.
TL;DR: In this paper, the direct synthesis of activated calcium with aryl halides in tetrahydrofuran (THF) gave the following compounds of the type RCaX in fair to good yields:
TL;DR: Dioxane concentrations and areal extent of dioxane in groundwater were greater than those of either TCA or THF, and a solid-phase extraction (SPE) method based on activated carbon disks was developed for the quantitative determination ofdioxane and THF.
Abstract: Groundwater contamination by cyclic ethers, 1,4-dioxane (dioxane), a probable human carcinogen, and tetrahydrofuran (THF), a co-contaminant at many chlorinated solvent release sites, are a growing concern. Cyclic ethers are readily transported in groundwater, yet little is known about their fate in environmental systems. High water solubility coupled with low Henry's law constants and octanol-water partition coefficients make their removal from groundwater problematic for both remedial and analytical purposes. A solid-phase extraction (SPE) method based on activated carbon disks was developed for the quantitative determination of dioxane and THF. The method requires 80 mL samples and a total of 1.2 mL of solvent (acetone). The number of steps is minimized due to the "in-vial" elution of the disks. Average recoveries for dioxane and THF were 98% and 95%, respectively, with precision, as indicated by the relative standard deviation of <2% to 6%. The method quantitation limits are 0.31 microg/L for dioxane and 3.1 microg/L for THF. The method was demonstrated by analyzing groundwater samples for dioxane and THF collected during a single sampling campaign at a TCA-impacted site. Dioxane concentrations and areal extent of dioxane in groundwater were greater than those of either TCA or THF.
TL;DR: A series of novel polyamide-imides (PAIs) with high glass transition temperature were prepared from diimide-dicarboxylic acid, 2,2-bis(trifluoromethyl)-4,4′-bis (trimellitimidophenyl)biphenyl ( BTFTB), by direct polycondensation with various diamines in N -methyl-2-pyrrolidinone using triphenyl phosphite and pyridine as condensing agents in the presence of dehydrating agent (Ca
TL;DR: In this paper, the physicochemical and structural properties of binary or ternary mixtures of 1- n -butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF 6 ])+ organic solvent were studied.
TL;DR: Complete regioselective separation of five pairs of isomeric dipalmitoyl polyalkenoyl glycerols with two to six double bonds in the unsaturated acyl residues has been achieved by RP-HPLC on a single ODS column.
Abstract: Complete regioselective separation of five pairs of isomeric dipalmitoyl polyalkenoyl glycerols with two to six double bonds in the unsaturated acyl residues has been achieved by RP-HPLC on a single ODS column. Four ODS columns with stationary phases containing different percentages of free silanol groups have been tested. Binary mobile phases of ACN admixed with dichloromethane, tetrahydrofuran, 1-propanol, 2-propanol, ethanol, or acetone have been examined. The choice of modifier depended on the nature of the stationary phase. The more polar solvents were better suited for stationary phases with higher percentage of free silanol groups. Isomeric species were eluted according to chain length, number of double bonds, and the position of the unsaturated acyl chain in the glycerol molecule. Retention increases in the order 20:5 < 22:6 < 18:3 < 20:4 << 18:2. Within each isomeric pair, the species with unsaturated acyl chain occupying either the sn-1- or the 3-position were retained preferentially. Complete simultaneous regioselective separation of 10 isomeric triacylglycerols in a single isocratic run on a single ODS column was demonstrated.
TL;DR: In this article, the authors investigated the formation of poly(N,N-dimethylacrylamide) (PDMA) networks in aqueous solutions of organic solvents.
TL;DR: An acid-labile dimethacrylate acetal crosslinker, di(metha-loyloxy-1-ethoxy)methane (DMOEM), was synthesized by the reaction of 2-hydroxyethyl methcrylate and paraformaldehyde using p-toluenesulfonic acid and toluene as catalyst and solvent, respectively as mentioned in this paper.
Abstract: An acid-labile dimethacrylate acetal cross-linker, di(methacryloyloxy-1-ethoxy)methane (DMOEM), was synthesized by the reaction of 2-hydroxyethyl methacrylate and paraformaldehyde using p-toluenesulfonic acid and toluene as catalyst and solvent, respectively. Group transfer polymerization was employed to use this cross-linker in the preparation of nine hydrolyzable polymer structures: one neat cross-linker network, one randomly cross-linked network of methyl methacrylate (MMA), and seven star-shaped polymers of MMA. Gel permeation chromatography (GPC) in tetrahydrofuran (THF) confirmed the narrow molecular weight distributions of the linear polymer precursors to the stars and demonstrated the increase in molecular weight upon the addition of cross-linker for the formation of star-shaped polymers. Characterization of the star polymers in THF using static light scattering and GPC showed that the molecular weights and the number of arms of each star polymer increased with an increase in the molar ratio of c...
TL;DR: The factors that determine the Wurtz-type reductive coupling of dichloroorganosilanes by alkali metals are reviewed in this article, and a strong recommendation is advanced for carrying out all such polysilane syntheses in tetrahydrofuran at ambient temperature, conditions under which the reaction gives far higher yields and generally much narrower product molecular weight distributions.
Abstract: The factors that determine the Wurtz-type reductive coupling of dichloroorganosilanes by alkali metals are reviewed. A strong recommendation is advanced for carrying out all such polysilane syntheses in tetrahydrofuran at ambient temperature, conditions under which the reaction gives far higher yields and generally much narrower product molecular weight distributions. The higher yields are attributed to the ability of the solvent to sequester the sodium ion and thereby stabilize the anionic chain carriers. The bimodal molecular weight distributions of the product polymers, which are ubiquitous when such reactions are carried out in high-boiling-point aromatic solvents under reflux, as is common practice, are attributed to it being a defect-diffusion-controlled polymerization at the alkali metal surface. The narrower molecular weight distributions that result from syntheses in tetrahydrofuran are attributed to the suppression of defect diffusion rates at lower temperatures.
TL;DR: In this paper, a hydrolyzable dimethacrylate crosslinker, 2-methyl-2,4-pentanediol (MPDMA), was synhesized by the reaction of 2 methyl-2.4- pentanediol and methacryloyl chloride in the presence of triethylamine.
Abstract: A hydrolyzable dimethacrylate cross-linker, 2-methyl-2,4-pentanediol dimethacrylate (MPDMA), was synhesized by the reaction of 2-methyl-2,4-pentanediol and methacryloyl chloride in the presence of triethylamine. This cross-linker was used to prepare a neat cross-linker network and three cross-linked star polymer model networks (CSPMNs) of methyl methacrylate (MMA), as well as star-shaped polymers of MMA, by group transfer polymerization (GTP). Gel permeation chromatography (GPC) in tetrahydrofuran (THF) confirmed the narrow molecular weight distributions (MWDs) of the linear polymer precursors, and demonstrated the increase in molecular weight (MW) on each successive addition of cross-linker or monomer. Characterization of the star polymers by static light scattering (SLS) in THF showed that star polymers with MPDMA cores bear a relatively small number of arms, between 7 and 35. All star polymers and polymer networks containing the MPDMA cross-linker were hydrolyzed at room temperature in neat trifluoroac...
TL;DR: In this paper, the excitation and the fluorescence steady-state spectroscopy of poly[2-methoxy-5-(2′-ethylhexoxy)-p-phenylene vinylene] (MEH-PPV) in two solvents and several concentrations were systematically studied.
TL;DR: In this article, multiwalled carbon nanotubes have been prepared by pyrolysing tetrahydrofuran (THF) in the presence of nickelocene.
TL;DR: In this article, the same Re(I) starting material with bis(2-mercaptoimidazolyl)methane, H2C(timMe)2, has been characterized by IR, 1H and 13C NMR spectroscopy, and also by X-ray crystallographic analysis.
TL;DR: In this paper, a novel gradient polymer, prepared by complex-radical terpolymerization of styrene (St), maleic anhydride (MA), and N-vinylpyrrolidone (NVP), was synthesized by use of a reversible addition-fragmentation chain transfer (RAFT) process.
Abstract: A novel “gradient” polymer, prepared by complex-radical terpolymerization of styrene (St), maleic anhydride (MA), and N-vinylpyrrolidone (NVP), was synthesized by use of a reversible addition−fragmentation chain transfer (RAFT) process. The terpolymerization was performed in tetrahydrofuran (THF) at room temperature under γ-ray irradiation in the presence of dibenzyl trithiocarbonate (DBTTC). The constants of complex-radical terpolymerization, complex formation, and some kinetic parameters for the monomer systems were studied by UV, 1H NMR, Kelen−Tudos methods, respectively. The equilibrium constant (K2) of 1:1 complex between MA and NVP was determined by UV method as 3.57 × 10-2 L/mol at 293.2 K in CHCl3. Obtained results show that the terpolymerization proceeded mainly through “complex” mechanisms in the state of near-binary copolymerization of St···MA (CTC1) and MA···NVP (CTC2) complexes. And as the big difference in the value of the reactivity ratios between the two complexes (r1 = 0.17 ± 0.01 and r2 ...