Interactions of γ-Cyclodextrin with the Mixed Micelles of Anionic Surfactants and Their Inclusion Complexes Formation

Interactions of γ-cyclodextrin (γ-CD) with the single and mixed micelles of sodium dodecyl sulfate (SDS) and sodium lauroyl sarcosine (SLAS) have been studied at different concentrations of γ-CD by using conductivity measurements. From conductivity data, the pure and mixed critical micellar concentration (cmc), the equivalent ionic conductivities of the monomeric species (Λ _m), the associated species (Λ _assc) and the micelle (Λ _mic), the degree of counterion dissociation (χ) in the presence of γ-CD have been evaluated from the slope of the conductivity versus concentration plots for the pure and binary mixture of surfactants. From the dependence of cmc of the surfactantson γ-CD concentration, we have deduced the association constant (K) of surfactant-γ-CD inclusion complexes assuming 2:1 stoichiometry. Theories of Clint, regular solution, and Motomura's have been used for the evaluation of ideality or nonideality of the mixed system. Mixed micelles were found to be rich in SDS content in the presence and the absence of γ-CD. The cmc values have been used to evaluate the transfer of standard free energy of micelles (ΔG⁰ _M,tr) from the aqueous medium to additive medium.     

Synthesis,Crystal Structure and Fluorescent Property of a Zn(Ⅱ) Complex with 1,3-Bis(imidazol-1-yl)benzene and 1,3-Benzenedicarboxylate

A novel zinc complex [Zn(BIB)(bdc)]n(1, BIB = 1,3-bis(imidazol-1-yl)benzene, bdc = 1,3-benzenedicarboxylate) has been synthesized in solvothermal conditions. The title complex was characterized by elemental analysis, IR spectra, thermal analysis, single-crystal and powder X-ray diffraction. The result proved that the alliance of BIB and aromatic carboxylic acids is good for the diversity of getatable structure. Complex 1 crystallizes in the monoclinic system of P2/c space group with a = 11.5591(10), b = 9.6239(8), c = 33.727(3) ?, β = 103.816(3)°, V = 3643.4(5) ?3, Z = 8, μ = 1.385 mm-1, F(000) = 1792, Dc = 1.603 g/cm3 and Mr = 439.72 g/mol. Additionally, luminescent properties of complex 1 are also investigated and it shows good fluorescence.     

Synthesis,Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd(Ⅱ) coordination polymer, namely, [Cd(1,3-bip)(3,5-pdc)]n(1,3-bip =1,3-bis(imidazol)propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid) has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis,powder X-ray diffraction(PXRD) and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178(7), b = 1.72502(12), c = 1.41635(6) nm, β =92.653(4)o, V = 3.4212(3) nm3, Z = 4, C316H15 Cd N5O4, Mr = 453.73, Dc = 1.762 g/cm, F(000) =1808, μ = 1.310 mm-1, R = 0.0899 and w R = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd(Ⅱ) ions and each Cd(Ⅱ) attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.     

Temperature-dependent Polymorphism in Co（II） Coordination Polymers from 5-Nitroisophthalate and 1,3-Bis（4-pyridyl）propane

The solvothermal reaction of 5-nitroisophthalic acid （H2nip）, 1,3-bis（4-pyridyl）pro- pane （bpp） and Co（NO3）2·6H：O at 130 and 160 ℃ gave rise to two polymorphic complexes [Co（bpp）（H20）（nip）], （1, 2）. Complex I belongs to monoclinic, space group C2/c with a = 14.489（6）, b = 18.242（8）, c = 19.414（9） A, β = 123.09（3）°, V = 4299（3） A3, Z = 8, C21H19CoN3O7, Mr = 484.32, Dc= 1.497 g/cm3, F（000） = 1992,/l = 0.847 mm-1. In complexes I and 2, bpp connects Co（II） into different 1D chains which are bridged by nip to form similar two-fold interpenetrating 3D frameworks.     

Study of the Inclusion Compound Formed between a Luminescent Europium(III) β-Diketonate Complex and γ-Cyclodextrin

A 1 : 1 inclusion compound between -CD and the tris chelate complex Eu(NTA)₃·2H₂O [NTA = 1-(2-naphthoyl)-3,3,3-trifluoroacetone)] was prepared and characterized in the solid-state by powder X-ray diffraction, thermogravimetric analysis, FTIR, ¹³C CP MAS NMR and photoluminescence spectroscopy. Possible host-guest interaction geometries were generated from ab initio calculations. The photoluminescence results reveal the presence of a metal-to-ligand energy transfer that is much more efficient than that previously reported for the analogous -CD adduct.     

Formation of (±)-1,2-O-Ethylidene-myo-Inositol During the Reaction Between Triethyl Orthoformate and myo-Inositol in DMSO

Besides myo-inositol monoorthoformate (1), (±)-1,2-O-ethylidene-myo-inositol (2) was obtained as another product in the reaction between triethyl orthoformate and myo-inositol in DMSO catalyzed by acid under N₂     

A Luminescent Cd(Ⅱ) Coordination Polymer Constructed from Isophthalic Acid and 1,3-Bis-(4-pyridyl)propane

A new coordination complex [Cd2(ip)2(bpp)]n(1, H2 ip = isophthalic acid, bpp = 1,3-bis-(4-pyridyl) propane) has been synthesized and structurally characterized. Crystal data for the title complex are as follows: triclinic system, space group P1 with a = 9.6724(6), b = 10.2243(6), c = 14.8205(9) ?, α = 88.927(5), β = 71.664(6), γ = 75.767(5)°, V = 1345.79(14) ?3, Mr = 751.29, Z = 2, F(000) = 740, Dc = 1.854 g/cm3, μ(Mo Kα) = 1.636 mm-1, R = 0.0259 and w R = 0.0623 for 4754 observed reflections with I 2σ(I). X-ray structure analysis reveals that complex 1 holds a 3D architecture based on α-Po primitive cubic units with the [Cd4(COO)8] units treated as 6-connected nodes. Solid-state properties for 1, such as infrared spectroscopy, elemental analyses, thermal stability and luminescent property, have also been investigated.     

Spectrophotometric Studies on the Inclusion Formation of β-Cyclodextrin with 3,4-(Methylenedioxyphenyl) Benzylideneaniline

Complexation of -cyclodextrin with 3,4-(methylenedioxyphenyl) benzylideneaniline has been studied in aqueous solution by means of spectrophotometry. It was observed that the complexation attains equilibrium very slowly. The equilibrium constant of the 1:1 complexation between -CD and MDBA was determined, and its dependence on temperature examined. Findings are discussed in light of host–guest intermolecular interactions. Two possible mechanisms of complexation are proposed.     

Synthesis of 1-Methyl and 1-Benzyl 3,5-Bis(ω-Mercaptoalkyl) Isocyanurates

1-Methyl and 1-benzyl 3,5-bis(-haloalkyl) isocyanurates were reacted with thiourea to obtain 1-methyl and 1-benzyl 3,5-bis[-[amino(imino)methylmercapto]alkyl] isocyanurates, respectively. Hydrolysis of the latter gave the corresponding 3,5-bis(-mercaproalkyl) izocyanurates.     

Comparative Study on the Effect of NaBr on the Interaction Between Alkyltrimethylammonium Bromide and β-Cyclodextrin

The effect of NaBr on the interaction between alkyltrimethylammonium bromide (CnTAB (n = 14 for TTAB and 16 for CTAB)) and ß-CD was studied by surface tension method. The first decrease in the γ_cmc of TTAB/ß-CD in the presence of NaBr mainly due to the elongated effective chain length of the hydrophobic part of the TTAB/ß-CD complexes; while the increase in the γ_cmc of both of the TTAB/ß-CD and CTAB/ß-CD in the presence of NaBr could be attributed to the close pack of CnTAB at the air/water interface.     

Synthesis,Crystal Structure and Characterization of a New Coordination Polymer from the Self-assembly of CoCl_2 Salt and Flexible Ligand 1,3-Bis（4-pyridyl）propane

A new 1D coordination polymer [Co(bpp)3Cl2(H2O)2]n 1 (bpp = 1,3-bis(4-pyridyl)-propane) was synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system,space group Ibca with a = 16.569(9),b = 17.240(10),c = 27.087(16) ,V = 7738(8) 3,Z = 8,Dc = 1.306 g/cm3,Mr = 760.65,λ(MoKa) = 0.71073 ,μ = 0.623 mm1,F(000) = 3192,the final R = 0.0678 and wR = 0.2011. The Co(II) atom is coordinated in a slightly distorted octahedral CoN4Cl2 geometry by two Cl atoms in the axial positions,four N atoms from the two bridging bpp ligands and two pendant bpp ligands. The CoN4Cl2 octahedra are connected by the bridging bpp ligands to form a 1D neutral coordination polymer chain. The chains are linked by face-to-face π-π interactions between adjacent pendant bpp ligands to give rise to a 3D supramolecular architecture. The photoluminescent investigation indicates that the emission of 1 is attributed to ligand-centered emission. The variable-temperature magnetic susceptibility measurement shows weak antiferromagnetic behavior in the complex.     

Physico-Chemical Investigation on the Interaction Between Ochratoxin A and Heptakis-2,6-di-O-Methyl-β-Cyclodextrin

Journal of Solution Chemistry - The interaction of ochratoxin A (OTA) with heptakis-2,6-di-O-methyl-β-cyclodextrin (DIMEB) in aqueous solutions at two different pHs (3.5 and 9.5) was studied...     

Luminescence Properties and Analytical Figures of Merits of Benzo(a)Pyrene Guanosine Adduct Adsorbed on α- β- and γ-Cyclodextrin/NaCl,and Trehalose/NaCl Solid Matrices

Abstract

Several cyclodextrin/NaCl and trehalose/NaCl mixtures were investigated as solid matrices for obtaining room-temperature luminescence from a benzo(a)pyrene (B(a)P) guanosine adduct. Room-temperature fluorescence (RTF) and room-temperature phosphorescence (RTP) intensities from the B(a)P-guanosine adduct were compared for different solid matrices. These results showed that 25% trehalose/NaCl, 1% α-cyclodextrin/NaCl, and 1% γ-cyclodextrin/NaCl solid matrices yielded strong fluorescence signals and moderately strong phosphorescence signals at room temperature from the B(a)P-guanosine adduct. In addition, the luminescence properties of pyrene, guanosine, guanosine 3′ -monophosphate free acid and guanosine 3′-monophosphate sodium salt on 1% α-, β-, and γ- cyclodextrin/NaCl solid matrices were obtained.     

1,1-Bis(trifluoromethyl)butadiene-1,3—A new fluorinated building block

Although 1,1-bis(trifluoromethyl)butadiene-1,3 (1) reacts with dimethylamine with selective formation of 1,4-adduct [trans-(CF₃)₂CHCHCHCH₂N(CH₃)₂], halogenation of 1 proceeds with predominant formation (>92%) of 1,2-adducts (CF₃)₂CCHCHXCH₂X (X = Cl or Br). Electrophilic conjugated addition of “ClF” or “BrF” to 1 proceeds exclusively with the formation of 1,2-adducts (CF₃)₂CCHCHFCH₂X (major) and (CF₃)₂CCHCHXCH₂F (X = Cl or Br). Difluorocarbene adds selectively to CHCH₂ moiety of 1 forming thermally stable vinylcyclopropane. In Diels-Alder reaction with linear or cyclic dienes (butadienes, cyclopentadiene, cyclohexadiene-1,3) and quadricyclane compound 1 behaves as dienophile providing for the reaction electron-deficient CHCH₂ bond. The relative rate of cycloaddition of 1 and other fluoroolefins to quadricyclane, measured by high temperature NMR, indicates that (CF₃)₂CCH acts as very strong electron-withdrawing substituent. Synthetic utility of products based on 1 was also demonstrated.     

A One-dimensional Transition Metal Complex Constructed from 24-Membered Hinge-shaped Macrocycles with Salicylic Acid and 1,3-Bis（4-pyridyl）propane

A new 1-D coordination polymer [Cd（Hsal）2（bpp）2] 1 was hydrothermally synthesi- zed by self-assembly of the corresponding metal oxide and salicylic acid （H2sal） with exo-bidentate flexible dipyridyl ligand 1,3-bis（4-pyridyl）propane （bpp）. X-ray crystal structure analysis reveals that complex 1 crystallizes in monoclinic,space group C2/c with a = 18.942（3）,b = 12.9309（19）,c = 16.504（2） A,β = 120.072（2）°,V = 3498.3（9）A^3,Z = 4,C40H38CdN4O6,Mr = 783.14,Dc = 1.487 g/cm^3,μ = 0.679 mm^-1,F（000） = 1608,R = 0.0619 and wR = 0.1435 for 3153 observed reflections （I 〉 2σ（I））. The most remarkable feature of 1 lies in the 1-D chain by repeating [Cd2（bpp）2] units which consist of a 24-membered macrocyclic ring. The 1-D motifs are further connected by C–H… O hydrogen bonds to generate a 2-D structure. In addition,thermal stability and luminescent property of compound 1 were also documented.     

X-ray Structure and Thermal Properties of a 1:1 Inclusion Complex Between Permethylated β-Cyclodextrin and Psoralen

The phytoalexin psoralen (7H-furo[3,2-g][1]benzopyran-7-one) has been included in heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) to yield a solid crystalline complex of formula TRIMEB-psoralen-H₂O. Its X-ray structural elucidation provides an accurate model for cyclodextrin–furocoumarin interaction. Thermal analysis (hot stage microscopy, differential scanning calorimetry, thermogravimetry) indicated complex dehydration in the range 40–100°C followed by melting at 137.1°C. The X-ray analysis showed that the elongated guest molecule induces elliptical distortion in the host molecule, with which it interacts via C-H ?O hydrogen bonding and hydrophobic interactions. The host molecule adopts a very similar conformation to that in the isostructural complex with l-menthol as guest. Water molecules bridge symmetry-related TRIMEB molecules by hydrogen bonding.     

Cyclodextrin as a Template for Molecular Assembly: Formation of Heterodimers Between a Polyamino- and a Polysulfonato-β-Cyclodextrin

A poly(hydroxyethylamino)- and a poly(sulfonatophenyloxy)--cyclodextrin derivative, bearing opposite ionic charges, have been shown by potentiometric titration to form stable pH-dependent heterodimers with each other in water. The formation constants of these dimers show that a very stable assembly is formed between the fully deprotonated sulfonato derivative and the fully protonated amino derivative (log K_a = 8.5), which constitutes the assembly of multiple extended atomic groupings on cyclodextrin as template.     

Formation of γ-oxoacids and 1H-pyrrol-2(5H)-ones from α,β-unsaturated ketones and ethyl nitroacetate

Michael addition of ethyl nitroacetate on α,β-unsaturated ketones followed by Nef oxidation under hydrolytic conditions yields γ-oxoacids instead of the corresponding α,δ-dioxoesters. A concerted decarboxylation step is proposed on the basis of computational results. Finally, conversion of the γ-ketoacids thus prepared into 1H-pyrrol-2(5H)-ones by reaction with primary amines under Paal-Knorr conditions is also reported.     

Syntheses,Structures, and Properties of Two Cobalt(Ⅱ) Coordination Complexes Based on(Fluorene-9,9-diyl) dipropanoic Acid and 1,3-Bis(imidazol-1-yl)butane Ligands

Two new cobalt(II) coordination complexes, namely [Co(HL)_2(biim)(H_2O)_2]_n·n H_2O(1) and [Co(Et L)_2(biim)]_n·3 n(H_2O)·2 n(Et HL)(2)(H_2L =(fluorene-9,9-diyl)dipropanoic acid, biim = 1,3-bis(imidazol-1-yl)butane), have been synthesized using the same starting reactants but different solvent medium. The two complexes exhibit distinctly different structures. Compound 1 exhibits a one-dimensional linear chain structure. However, complex 2 reveals a one-dimensional zigzag chain structure. Thermogravimetric analyses(TGA) and luminescent properties of these two complexes have been discussed.     

Synthesis,Crystal Structure and Theoretical Calculations of a Nickel(Ⅱ) Coordination Polymer Assembled by 4,4'-Oxydibenzoic Acid and 1,3-Bis(imidazol-1-ylmethyl)-benzene Ligands

A new metal-organic coordination polymer [Ni(oba)(mbix)(H2O)]n·n H2O(H2oba = 4,4‘-oxydibenzoic acid,mbix = 1,3-bis(imidazol-1-ylmethyl)-benzene) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR,TG,UV and single-crystal X-ray diffraction.Green crystals crystallize in the triclinic system,space group P1 with a = 10.1915(18),b = 11.415(2),c = 12.314(2)?,α = 74.263(3),β = 84.545(2),γ = 74.369(3)o,V = 1327.6(4) ?,C28H26N4 Ni O7,Mr = 589.24,Dc = 1.474 g/cm3,F(000) = 612,Z = 2,μ(Mo Kα) = 0.786 mm-1,the final R = 0.0332 and w R = 0.0869 for 4622 observed reflections(I 2σ(I)).The structure of 1 exhibits a one-dimensional chain-like structure.In addition,natural bond orbital(NBO) analysis was performed by the PBE0/LANL2 DZ method in Gaussian 03 Program.The calculation results show obvious covalent interaction between the coordinated atoms and Ni(Ⅱ) ion.