Syntheses,structures, and luminescence of coordination compounds based on N-containing polycarboxylates

Six coordination compounds constructed by two structurally related flexible nitrogen-containing polycarboxylate ligands 2,2′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)dibenzoic acid (H₂L1) and 5,5′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)diisophthalic acid (H₄L2) have been synthesized: [Ni(H₂O)₆]?·?L1?·?(C₂H₅OH)_0.5?·?H₂O (1), [Co(L1)(L3)]?·?CH₃OH (2), [Ni(L1)(L3)]?·?CH₃OH (3), [Zn(L1)(L3)]?·?CH₃OH (4), [Cd(L1)(L3)]?·?CH₃OH (5), and [Zn(L2)_0.5(phen)]?·?C₂H₅OH (6), where L3?=?3,4?:?9,10?:?17,18?:?23,24-tetrabenzo-1,12,15,26-tetraaza-5,8,19,22-tetraoxacyclooctacosan and phen?=?1,10-phenanthroline. The crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 displays a discrete structure, which is further linked by hydrogen bonds to form a 2-D supramolecular layer. Compounds 2–5 display similar structures. These compounds possess 1-D meso-chain structures linked by L1 and metals. The C–H?···?π interactions from neighboring chains extend the chains in different directions, giving a 3-D plywood network. Compound 6 possesses 2-D layers, which are further linked by hydrogen-bonding interactions to generate a 3-D supramolecular architecture.     

Synthesis and Properties of a Sulfonic Acid-Containing Gemini Surfactant

A novel sulfonic acid-containing gemini surfactant, 6,6′-(butane-1,4-diylbis(oxy)) bis(3-nonylbenzenesulfonic acid), 9BA-4-9BA, was synthesized in high purity and high yield using a facile preparation pathway, and characterized by FTIR, ¹H NMR, and elemental analysis. The content of two sulfonic acid groups was measured by the acid-base titration. DSC and TGA were used to reveal the thermal properties and the product purity. The surface properties of 9BA-4-9BA were evaluated by equilibrium surface tension measurement. It shows that its CMC was 0.65 mmol/L, while the C₂₀ of 0.018 mmol/L was above two orders of magnitude lower than that of traditional monomeric surfactants such as SDS and SDBS, indicating excellent efficiency of micelle formation and reduced surface tension.     

分光光度滴定法测某些多齿配体与Ni(Ⅱ)配合物的稳定常数

制备了多齿大环配体1,4,7,10-四氮杂环十二烷(L1);1,4,8,11-四(2-羟乙基)-1,4,8,11-四氮杂环十四烷(L2)和无环多齿配体;3-(2-氨基环己氨基)-2-(2-氨基环己氨基甲基)丙酸(L3),4,7,10-十三烷二腈三氢氯化物(L4),2,2′-(1,2-二乙基-双((甲基二氮杂烷基)二乙醇(L5)and 1,1′-(1,2-二乙基-双((2-氨基乙基)二氮杂烷基))-2-二丙醇(L6),并用FTIR,NMR和MS进行了表征,用配有二极管阵列检测器、蠕动泵和pH计的UV-VIS光度仪,经分光光度滴定法测定了它们与Ni髤的配合物的稳定常数。将稳定常数的数据与配体的开链和环状结构特性进行了关联讨论。还讨论了侧基对配合物稳定常数的影响。     

Potent inhibition of protein tyrosine phosphatases by quinquedentate binuclear copper complexes: synthesis, characterization and biological activities

Three phosphono-containing multidentate ligands were employed to synthesize quinquedentate binuclear copper complexes, [Cu(2)L(2)] (1-3) (H(2)L1 = diethyl(propane-1,3-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate), H(2)L2 = diethyl(ethane-1,2-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate), H(2)L3 = diethyl(hexane-1,6-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate)), which were characterized by elemental analysis, IR, X-ray diffraction analysis, electrospray ionization mass spectra. Complexes 1 and 2 crystallized in the triclinic system with space group P ?1. The speciation of the Cu-H(2)L1 system in aqueous solution was investigated by potentiometric pH titrations. The three dicopper complexes exhibited potent and almost the same inhibitory effects against protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TCPTP) with IC(50) of 0.16-0.24 μM, about 10-fold stronger inhibition than against Src homology phosphatase 1 (SHP-1), 30-fold than against Src homology phosphatase 2 (SHP-2) and more than 100-fold than against megakaryocyte protein-tyrosine phosphatase 2 (PTP-MEG2). Fluorescence titrations revealed complex 1 bond to the five PTPs with molar ratio of 1:1 and binding constants of 1.62 × 10(6), 3.09 × 10(6), 1.95 × 10(5), 2.24 × 10(5), 1.55 × 10(4) M(-1) for PTP1B, TCPTP, SHP-1, SHP-2 and PTP-MEG2, respectively, consistent with the inhibitory abilities from IC(50) and K(i) values. Also, the three copper complexes could inhibit phosphatase activity of cell extracts from C6 rat glioma cells. The results suggested the structures of copper complexes influence selectivity over different PTPs.     

Developments in transfer hydrogenations of aromatic ketones catalyzed by boron compounds

Boron complexes BL1 and BL2 were prepared from O-donor ligands, 2,2′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L1) and 2,2′-(propane-1,3-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L2). The complexes were fully characterized by ¹H and ¹³C NMR, LC-MS/MS, TGA/DTA, UV-Vis, elemental analysis, SEM, and FTIR. The transfer hydrogenation of acetophenone derivatives was investigated by the boron complexes in the presence of isoPrOH, as the hydrogen source, under basic condition with NaOH. The results showed that the boron complexes were promising catalytic precursors for transfer hydrogenation of aromatic ketones in 0.1 M isoPrOH solution (up to 99%). Both steric and electronic factors of this class of molecules had a significant impact on the catalytic properties.     

One-pot synthesis of bis-1,5,3-dithiazepanes from ethane-1,2-dithiol, formaldehyde, and ammonium salts

An efficient one-pot procedure has been developed for the synthesis of bis-1,5,3-dithiazepanes by reaction of ethane-1,2-dithiol with formaldehyde and ammonium salts. According to the X-ray diffraction data, the heterorings in 3,3′-[ethane-1,2-diylbis(sulfanediylmethanediyl)]bis(1,5,3-dithiazepane) in crystal adopt a chair conformation with axial orientation of the substituent on the nitrogen atom.     

Synthesis,structure, DNA interaction,and hydrolytic function toward bis(<Emphasis Type="Italic">p</Emphasis>-nitrophenyl) phosphate of a heterobinuclear macrocyclic complex

An asymmetrical bis-pyridine pendant-armed macrocyclic heterobinuclear complex, [ZnNiL](ClO₄)₂·CH₃CN (H₂L was derived from the condensation between 3,3′-((ethane-1,2-diylbis((pyridin-2-ylmethyl)azanediyl))bis(methylene))bis(2-hydroxy-5-methylbenzaldehyde) and 1.3-diaminopropane), has been synthesized and characterized by physico-chemical and spectroscopic methods. The asymmetric unit contains two complete macrocyclic complexes that are nevertheless quite similar to one another. The Zn–Ni separations, bridged by the two phenoxides, are 3.107 and 3.141 Ǻ, respectively. The phosphate hydrolysis catalyzed by the complex was investigated using bis(4-nitrophenyl)phosphate (BNPP) as the substrate. The catalytic rate constant (k _cat) is 1.64 × 10⁻³ s⁻¹ at pH 7.4 and 25 °C, which is 10⁸-fold higher than that of the corresponding uncatalyzed reaction. The interaction between the complex and calf thymus (CT) DNA was investigated by UV–vis absorption, viscosity experiments, and cyclic voltammetry. The complex shows good binding propensity to calf thymus DNA via intercalation with a binding constant of 5 × 10⁴ M⁻¹. The agarose gel electrophoresis studies show that the complex has a concentration-dependent DNA cleavage activity.     

Synthesis and crystallographic studies of two new 1,3,5‐triazines

The synthesis and characterization of two new 1,3,5‐triazines containing 2‐(aminomethyl)‐1H‐benzimidazole hydrochloride as a substituent are reported, namely, 2‐{[(4,6‐dichloro‐1,3,5‐triazin‐2‐yl)amino]methyl}‐1H‐benzimidazol‐3‐ium chloride, C₁₁H₉Cl₂N₆⁺·Cl^? ( 1 ), and bis(2,2′‐{[(6‐chloro‐1,3,5‐triazine‐2,4‐diyl)bis(azanediyl)]bis(methylene)}bis(1H‐benzimidazol‐3‐ium)) tetrachloride heptahydrate, 2C₁₉H₁₈ClN₉²⁺·4Cl^?·7H₂O ( 2 ). Both salts were characterized using single‐crystal X‐ray diffraction analysis and IR spectroscopy. Moreover, the NMR (¹H and ¹³C) spectra of 1 were obtained. Salts 1 and 2 have triclinic symmetry (space group P) and their supramolecular structures are stabilized by hydrogen bonding and offset π–π interactions. In hydrated salt 2 , the noncovalent interactions yield pseudo‐nanotubes filled with chloride anions and water molecules, which were modelled in the refinement with substitutional and positional disorder.     

Inclusion complexes of cyclodextrins with 4-amino-1,8-naphthalimides (part 2)

Fluorescence spectroscopy was used to characterize inclusion compounds between 4-amino-1,8-naphthalimides (ANI) derivatives and different cyclodextrins (CDs). The ANI derivatives employed were N-(12-aminododecyl)-4-amino-1,8-naphthalimide (mono-C₁₂ANI) and N,N′-(1,12-dodecanediyl)bis-4-amino-1,8-naphthalimide (bis-C₁₂ANI). The CDs used here were α-CD, β-CD, γ-CD, HP-α-CD, HP-β-CD and HP-γ-CD. The presence of CDs resulted in pronounced blue-shifts in the emission spectra of the ANI derivatives, with increases in emission intensity. This behavior was parallel to that observed for the dyes in apolar solvents, indicating that inclusion complexes were formed between the ANI and the CDs. Mono-C₁₂ANI formed inclusion complexes of 1:1 stoichiometry with all the CDs studied. Complexes with the larger CDs (HP-β-CD, HP-γ-CD and γ-CD) were formed by inclusion of the chromophoric ANI ring system, whereas the smaller CDs (α-CD, HP-α-CD and β-CD) formed complexes with mono-C₁₂ANI by inclusion of the dodecyl chain. Bis-C₁₂ANI formed inclusion complexes of 1:2 stoichiometry with HP-β-CD, HP-γ-CD and γ-CD, but did not form inclusion complexes with α-CD, HP-α-CD and β-CD. The data were treated in the case of the large CDs using a Benesi-Hildebrand like equation, giving the following equilibrium constants: mono-C₁₂ANI:HP-β-CD (K ₁₁ = 50 M^?1), mono-C₁₂ANI:HP-γ-CD (K ₁₁ = 180 M^?1), bis-C₁₂ANI:HP-β-CD (K ₁₂ = 146 M^?2), bis-C₁₂ANI:HP-γ-CD (K ₁₂ = 280 M^?2).     

Synthesis of 4,6-dimethyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile by condensation of cyanothioacetamide with acetaldehyde and 1-(prop-1-en-2-yl)piperidine

Three-component condensation of cyanothioacetamide with acetaldehyde and 1-(prop-1-en-2-yl)-piperidine afforded 4,6-dimethyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile which was alkylated with alkyl halides to obtain substituted 2-alkylsulfanyl-4,6-dimethylpyridine-3-carbonitriles, (3-amino-4,6-dimethylthieno-[2,3-b]pyridin-2-yl)(4-cyclohexylphenyl)methanone, and 2,2′-[ethane-1,2-diylbis(sulfanediyl)]bis(4,6-dimethylpyridine-3-carbonitrile).     

Organische Phosphorverbindungen XXXVII. Darstellung und Eigenschaften von Bis-(dialkoxyphosphonyl-methyl)-, Bis-(alkoxyphosphinyl-methyl)-und Bis-(oxophosphoranyl-methyl)-phosphinsäureestern sowie der entsprechenden Säuren [1]

Bis-chloromethyl-alkyl-and - aryl-phosphine oxides, (CICH₂₎₂P(O)R, which are obtained by reaction of (CICH₂₎₂P(O)Cl with GRIGNARD reagents, undergo a MICHAELIS -ARBUSOV reaction when heated for several hours with trivalent phosphorus esters (phosphites, phosphonites, or phosphinites) at 170–180°C. The reaction affords bis-(dialkyloxyphosphonyl-methyl)-, bis (alkyloxyphosphinyl-methyl)-, and bis-(oxophosphoranyl-methyl)-, -alkyl- or -aryl-phosphine oxides, R(O)P[CH₂P(O)R′R″]₂ R = CH₃, C₂H₅, n-C₈H₁₇, n-C₁₂H₂₅, C₆H₅; R′ and R″ = C₂H₅O, C₄H₉O, C₆H₅, CH₃ in good yields. Conversion of the compounds containing alkyloxy groups to the free acids is achieved by refluxing with conc. HCl. Bis-(dihydroxyphosphonyl-methyl)-dodecylphosphine oxide, n-C₁₂H₂₅(O)P[CH₂P(O) (OH)_2]2, obtained by hydrolysis of the all-ethyl ester, titrates in aqueous solution as a tetrabasic acid with breaks at pH = 4 (two equivalents), pH = 6,9 (one equivalent) and pH = 9,6 (one equivalent). This acid, its disodium salt (m. p. 405–410°) and its tetrasodium salt (m.p. > 460°) are surface active and are excellent chelating agents. The ¹H- and ³¹P-NMR. spectra of all the compounds prepared are discussed.     

A hydro­gen-bonded `trimer' of two symmetric dipyridones

The isomers 3,3′-(1,2-ethynediyl)­bis­(2-pyridone), (I), and 6,6′-(1,2-ethyne­diyl)­bis­(2-pyridone), (II), were designed to form a hydrogen-bonded pair through alignment of their complementary cyclic lactam moieties. Instead, an equimolar mixture of (I) and (II) dissolved in methanol produced crystals of 3,3′-(1,2-ethynediyl)­bis(2-pyridone)–6,6′-(1,2-ethynediyl)­bis(2-py­ri­done)–methanol (1/2/2), 0.5C₁₂H₈N₂O₂·C₁₂H₈N₂O₂·CH₄O, in which one mol­ecule of (I), situated at a center of symmetry, is hydrogen bonded to two mol­ecules of (II) and to two mol­ecules of methanol.     

Octahedral iron(II) complexes with pyridyl triazine and bipyridine ligands – synthesis,computational studies,mechanisms and kinetics with 1,10-phenanthroline and 2,2′,6,2″-terpyridine

[Bis(3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine)(2,2′-bipyridine)iron(II)], [Fe(PDT)₂(bpy)]²⁺ (1), [bis(3-(4-phenyl-2-pyridyl)-5,6-diphenyl-1,2,4-triazine)(2,2′-bipyridine)iron(II)], [Fe(PPDT)₂(bpy)]²⁺ (2), [bis(2,2′-bipyridine)(3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine)iron(II)], [Fe(PDT)(bpy)₂]²⁺ (3), and [bis(2,2′-bipyridine)(3-(4-phenyl-2-pyridyl)-5,6-diphenyl-1,2,4-triazine)iron(II)], [Fe(PPDT)(bpy)₂]²⁺ (4) have been synthesized and characterized. Substitution of the triazine and bipyridine ligands from the complexes by nucleophiles (nu), namely 1,10-phenanthroline (phen) and 2,2′,6,2″-terpyridine (terpy) was studied in a sodium acetate-acetic acid buffer over the pH range 3–6 at 25, 35, and 45°C under pseudo-first order conditions. Reactions are first order in the concentration of complexes 1–4. The reaction rates increase with increasing [nu] and pH whereas ionic strength has no effect on the rate. Straight-line plots with positive slopes are observed when the k_obs values are plotted against [nu] or 1/[H⁺]. The substitution reactions proceed by dissociative as well as associative paths and the latter path is predominant. Observed low E_a values and negative ΔS^# values support the dominance of the associative path. Phenyl groups on the triazine ring modulate the reactivity of the complexes. The π-electron cloud on the phenyl rings stabilizes the charge on metal center by inductive donation of electrons toward the metal center, resulting in a decrease in reactivity of the complex and the order is 1 < 2 < 3 < 4. Density functional theory (DFT) calculations also support the interpretations drawn from the kinetic data.     

Crystal structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ2-chloro)hexachlorodimercurate(II)

The crystal and molecular structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ₂-chloro)hexachlorodimercurate(II) C₄H₁₆Hg₂Cl₈N₈S₄ (I), where α,α′-dithio-bis(formamidine) is C₂H₆N₄S₂, was solved. Crystals are monoclinic, a = 8.6417(6) Å, b = 14.648(1) Å, c = 10.2111(8) Å, β = 104.949(1)°, V = 1248.8(2) ų, space group P2₁/n, Z = 4. The crystal structure is built of HgCl ₄ ^2? ions linked via inversion centers into [Hg₂Cl₈]^4? pairs and C₂H₈N₄S ₂ ²⁺ cations. [Hg₂Cl₈]^4? anions and C₂H₈N₄S ₂ ²⁺ cations form alternating layers linked by N-H…Cl hydrogen bonds into a framework structure.     

Large magnetic anisotropy of chromium(III) ions in a bis(ethylenedithio)tetrathiafulvalenium salt of chromium bis(dicarbollide), (ET)<Subscript>2</Subscript>[3,3′-Cr(1,2-C<Subscript>2</Subscript>B<Subscript>9</Subscript>H<Subscript>11</Subscript>)<Subscript>2</Subscript>]

The synthesis of a radical-cation salt based on a derivative of tetrathiafulvalene, (ET)₂[3,3′-Cr(1,2-C₂B₉H₁₁)₂] (ET?=?bis(ethylenedithio)tetrathiafulvalenium), was accomplished by electrochemical anodic oxidation of ET in the presence of (Me₄N)[3,3´-Cr(1,2-C₂B₉H₁₁)₂] in the galvanostatic regime. An electric conductivity σ (293 K)?=?7 × 10^?3 Ohm^?1 cm^?1 with semiconductor activation energy E_a???0.1 eV in the range of 127–300 K was observed. The crystal structure of (ET)₂[3,3′-Cr(1,2-C₂B₉H₁₁)₂] was determined by X-ray diffraction at 173 K, revealing the presence of structural tetramers in radical-cation stacks. The magnetic properties of the complex were investigated in the temperature range 1.8–300 K using magnetometry and EPR, showing that the magnetic structure of (ET)₂[3,3′-Cr(1,2-C₂B₉H₁₁)₂] consists of two independent magnetic subsystems. Cation radicals form a rectangular magnetic lattice in the ab-plane with significant antiferromagnetic exchange interactions. The chromium bis(dicarbollide) anions are characterized by unusually strong positive zero-field splitting of the Cr(III) ions, which was confirmed by ab initio calculations.     

Synthesis of racemic and enantiomerically pure 2′-thia-2′,3′-dideoxycytidine as potential anti-hepatitis B virus agents

A novel class of nucleosides with the C₁, atom bonded to three hetero atoms was synthesized. 2′-Thia-2′,3′-dideoxycytidine was the pilot compound of this series. (±)-β-2′-Thia-1′,3′-dideoxycytidine ( 6 ) and (±)-α-2′-thia-2′,3′-dideoxycytidine ( 7 ) were synthesized from (±)-3-mercapto-1,2-propanediol. The synthesis of the enantiomerically pure 2′-thia-2′,3′-dideoxycytidines (α-D-form, β-D-form, α-1-form and β-L-form) from optically pure (S)-(2,2-dimethyl-1,3-dioxalan-yl)methyl p-toluenesulfonate ( 8 ) and its (R)-isomer 18 was also described. The preliminary biological results showed that (+)-β-D-2′-thia-2′,3′-dideoxycytidine ( 26 ) was the most active against human hepatitis B virus with an ED₅₀ of 3 μM.     

The hapticity of octafluorocyclooctatetraene in its first-row mononuclear transition metal carbonyl complexes: effect of perfluorination

The iron tricarbonyl complex of octafluorocyclooctatetraene was synthesized by Hughes and co-workers and shown by X-ray crystallography to have a trihapto–monohapto structure (η^3,1-C₈F₈)Fe(CO)₃ in contrast to the tetrahapto structure (η⁴-C₈H₈)Fe(CO)₃ formed by the non-fluorinated cyclooctatetraene. This difference has stimulated a comprehensive density functional theoretical study of the octafluorocyclooctatetraene metal carbonyl complexes (C₈F₈)M(CO) _n (n = 4, 3, 2, 1 for M = Ti, V, Cr, Mn, and Fe; n = 3, 2, 1 for M = Co, Ni) for comparison with their hydrogen analogues (C₈H₈)M(CO) _n . In most such systems, the substitution of fluorine for hydrogen leads to relatively small changes in the preferred structures. However, for the iron carbonyl derivatives (C₈X₈)Fe(CO)₃ (X = H, F), the difference observed experimentally has been confirmed by theory with (η^3,1-C₈F₈)Fe(CO)₃ and (η⁴-C₈H₈)Fe(CO)₃ being the lowest energy structures by 4 and 14 kcal/mol, respectively. The ligand exchange reactions C₈H₈ + (C₈F₈)M(CO) _n  → C₈F₈ + (C₈H₈)M(CO) _n are predicted to be exothermic for almost all of the systems considered, with the (η^3,1-C₈X₈)Fe(CO)₃ system being the main exception. This suggests that the C₈F₈ ligand generally bonds more weakly to transition metals than the C₈H₈ ligand in accord with the electron-withdrawing effect of the ligand fluorine atoms.     

The structure of 1,3-dichloropropyne as determined by gas electron diffraction and comparison with microwave data

The structure of 1,3-dichloropropyne has been studied by gas electron diffraction. The resulting parameters r_a have been converted into r_α^o distances. A geometrical structure has been fitted to these internuclear distances. Thus the following parameters (r_α^o) have been determined: r(C₁-Cl₁) = 1.629 (10) A, r(C₁C₂) = 1.201 (13) Å, r(C₃-Cl₂) = 1.791 (6) A, ∠(C₂-C₃-Cl₂) = 111.1° (1.0°), ∠(H-C₃-H) = 98.8° (3.1°), ∠(C₂-C₃-H) = 108.7° (3.2°). ∠(Cl₁-C₁C₂) = 176.6° (1.1°), ∠(C₁C₂-C₃) = 182.7° (1.4°). Inconsistencies have been detected between our results and the rotational constants reported by Günther and Zeil. Discussion of the problem including rotational constants of the first excited vibrational state leads to the conclusion that the observed discrepancies are due to temperature effects.     

Effect of ethylene glycol on micellization and micellar-catalyzed alkaline hydrolysis reaction of a cationic surfactant at 293–313 K

Changes in critical micellar concentrations (CMC’s) of gemini surfactant, α, ω-ethane bis(dimethyl cetyl ammonium bromide) (C₁₆-2-C₁₆) with different concentrations of ethylene glycol (EG) addition have been investigated by electrical conductivity method. Subsequently, alkaline hydrolysis of ethyl acetate (EA) in the presence of C₁₆-2-C₁₆ and C₁₆-2-C₁₆-EG has been studied conductometrically at 303.2 and 313.2 K, respectively. It was found that an increase in concentrations of EG added to C₁₆-2-C₁₆ aqueous solutions caused an increase in CMC’s of C₁₆-2-C₁₆, provoked by the decrease in the interfacial Gibbs energy contribution to G _M^∘. The hydrolysis of EA showed catalytic and restrained dual behavior in the presence of surfactant, it may be related to higher microviscosity and change of morphology with increased surfactant for C₁₆-2-C₁₆ at higher concentration. Addition of EG did not change microenvironment in micellar interfacial region significantly, which had less effect on gemini C₁₆-2-C₁₆ micellar catalytic efficiency.