Synthesis of N-(4′-Benzo[15-crown-5])thiophenoxyphenylaminoglyoxime and its complexes with some transition metals

4-(Chloroacetyl)diphenyl thioether (1) was synthesized from chloroacetyl chloride and diphenyl thioether in the presence of AlCl₃ as catalyst in a Friedel-Crafts reaction. Subsequently, its keto oxime (2) and glyoxime (3) derivatives were prepared. N-(4′-Benzo[15-crown-5]thiophenoxyphenylaminoglyoxime (H₂L) and its sodium chloride complex (H₂L · NaCl) were prepared from 4-(thiophenoxy)chlorophenylglyoxime (3), 4′-aminobenzo[15-crown-5] and sodium bicarbonate or sodium bicarbonate and sodium chloride. Ni(II), Co(II) and Cu(II) complexes of H₂L and H₂L · NaCl have a metal–ligand ratio of 1:2 and the ligand coordinates through the two N atoms, as do most of the vic-dioximes. The BF₂-capped Ni(II) mononuclear complex of the vic-dioxime was prepared. The macrocyclic ligands and their transition metal complexes were characterized on the basis of FT-IR, ¹H NMR, ¹³C NMR spectroscopy and elemental analyses data.     

Complexes of Some Metal Nitrates with 4′-Nitrobenzo-15-Crown-5

Complexes of Ag, Cu, Ca, Nd, and Er nitrates with 4-nitrobenzo-15-crown-5 (NB15C5) were synthesized and their IR absorption spectra were studied. Macrocyclic conformation in the complexes was determined. The structures of the complexes were proposed with account of the data of IR absorption spectra and of the previous X-ray diffraction study. In the Ag, Cu, and Ca complexes, NB15C5 was found in the inner sphere, while in the Nd and Er complexes, it was found to be the outer-sphere ligand.     

Synthesis of 4′-Carboxy-benzo-30-crown-10 and a Thermodynamic Study of Its Complexes with Thallium and Alkali Cations in Acetonitrile Solution

A synthetic procedure has been developed for the preparation of 4-carboxy-benzo-30-crown-10. The formation of Na+, K+, Rb+, Cs+ and Tl+ complexes with the large crown ether was investigated conductometrically in acetonitrile solution at various temperatures. The formation constants of the resulting 1:1 complexes were determined from the molar conductance-mole ratio data. It was found that the stability of the complexes vary in the order Tl+ > K+ > Rb+ > Cs+ > Na+. The data obtained in this study support the existence of a wrap around structure for the above complexes in solution. The enthalpy and entropy of complexation reactions were determined from the temperature dependence of the formation constants. In all cases, the complexes were enthalpy stabilized but entropy destabilized. The resulting TS° vs. H°plot showed a fairly good linear correlation, indicating the existence of an entropy-enthalpy compensation in the large crown complexation reactions.     

Sandwich Complexes of the As_4～(2-) Aromatic Ring with Some Transition Metals

The equilibrium geometries,energies,harmonic vibrational frequencies,and nucleus independent chemical shifts(NICS) of the new type sandwich structures [As4MAs4]n-(M = Fe,Co,Ni,Ru,Rh,Pd,Os,Ir and Pt;n = 0,1 or 2) are investigated at the B3LYP level.All the [As4MAs4]n-species adopt staggered(D4d) conformations as their stable structures and eclipsed(D4h) conformations as their transition states,and once the sandwich complexes are formed,the As42- square properties remain unchanged.The NICS calculation confirms that the complexes of Fe,Co,and Ni are aromatic with negative NICS values,and those of Ru,Rh,and Ir exhibit slight aromaticity,while those of Pd,Os,and Pt show slight antiaromaticity.     

Synthesis under Micromave Irradition and Crystal Structure of 4′-Acetylbenzo-15-crown-5thiosemicarbazone

The title compound is a bifunctional receptors including a thiourea group and a crown ether ring. Due to many possible potentials as a new class of reagents for membrane transports, ion-selective electrodes as well as reaction catalysts, the design and synthesis of bifunctional receptors for simultaneous binding of cations and anions is of ongoning interest in srpramolecular chemistry1-5. In bifunctional receptors, the binding sites for anions and cations are covalently linked so as to exhibit…     

Spectrophotometric study of the charge transfer complexes of 4′-nitrobenzo-15-crown-5 and benzo-15-crown-5 with iodine in nonaqueous solvents

The formation of charge transfer complex between iodine with 4’-nitrobenzo-15-crown-5（NB15C5） and benzo-15-crown-5 （B15C5） is investigated spectrophotometrically in chloroform and dichloromethane（DCM） solutions at 25℃.The pseudo-first-order rate constants for the transformation process were evaluated from the absorbance-time data and found to vary in the order of DCM > CHCl₃.The values of the formation constant,K_f,for each complex are evaluated from Benesi-Hilebrand equation. Stability of the resulting complex in two solvents was also found to vary in the order of DCM > CHCl₃.     

Rosenmund-Braun Reaction Products 4′,5′-Dicyanobenzo-15-crown-5 and 4′,5′-Dicyanobenzo-15-crown-5,4′-cyano-5′-cyano(bromo)benzo-15-crown-5 Hydrates: Spectroscopic Properties and Crystal Structure

The products of 4′,5′-dibromobenzo-15-crown-5 (I) cyanation by the Rosenmund-Braun reaction are studied by the ¹H NMR and IR spectroscopy methods. X-ray diffraction analysis of two isolated products, i.e., di(4′,5′-dicyanobenzo-15-crown-5) 1.6 hydrate {(CN)₂B15C5}₂ · 1.6H₂O (IIa) and 4′,5′-dicyanobenzo-15-crown-5,4′-cyano-5′-cyano(bromo)benzo-15-crown-5 dihydrate (CN)_3.85Br_0.15(B15C5)₂ · 2H₂O (III) is performed. Crystals IIa are monoclinic, a = 15.882(2) Å, b = 11.412(2) Å, c = 18.484(3) Å, β = 100.717(3)°, V = 3291.7(9) ų, Z = 4, space group P2₁/c, R = 0.0746 for 4775 reflections with I > 2σ(I). Crystals III are monoclinic, a = 15.956(3) Å, b = 11.425(2) Å, c = 18.865(4) Å, β = 99.32(3)°, V = 3394(1) ų, Z = 4, space group _P2₁/_{c, R} = 0.0692 for 2070 reflections with I > 2σ(I). Compounds IIa and III have similar structures with two crystallographically independent molecules in each (A and B in IIa; C and D in III). Four of the five O atoms of a macrocycle in molecules A and C form hydrogen bonds with the water molecules. The latter molecules lie above and below the cycle plane at a distance of ～2 Å from this plane. The A and C molecules have identical conformations (TTG TTG TTG TTG TTC) that differ from those of molecules B (TTG TGG STT SSG TTC) and D (TTC TSG STT SSG TTC).     

Synthesis of Unsymmetrical Bissalicylaldimine Ligands and bis-Schiff Base Cobalt Complexes with Benzo-10-aza-15-crown-5 Pendant

Novel unsymmetrical bissalicylaldimine bis-Schiff bases with a benzo-10-aza-15-crown-5 pendant and their cobalt complexes have been synthesized via condensation of 3 or 5-[（benzo-10-aza-15-crown-5）-10-ylmethyl] salicylaldehyde with the half unit Schiff bases and characterized by ^1H NMR, IR, mass spectroscopy, elemental analysis, molar conductances and molar magnetic susceptibility.     

Synthesis and applications of (5-substituted benzimidazolo)-benzo-15-crown-5 and 4,4′-bis-benzimidazolo-dibenzo-15-crown-5 for the colorimetric detection of Au3+

In the present work, we have reported the synthesis of benzimidazoles functionalized crown ether derivatives of 4-formyl benzo-15-crown-5/4,4′-diformyl dibenzo-15-crown-5 and substituted diamine pyridine using sulfamic acid as a catalyst in DMSO. These molecules are used for the colorimetric determination of Au³⁺ selectively among other metal cations such as Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺, Hg²⁺, Au³⁺ and Ag⁺ ions_.     

Zn complex with N-(4′-Benzo-15-crown-5)-2-(amino-N-tosyl)-phenylaldimine: Synthesis, crystal structure, and vibration spectrum

The ZnL₂ complex (I) (HL = N-(4′-benzo-15-crown-5)-2-(amino-N-tosyl)phenylaldimine) is synthesized and studied by IR spectroscopy and X-ray diffraction analysis. The crystals are monoclinic: a = 23.139(2) Å, b = 19.931(2) Å, c = 14.604(2) Å, β = 121.20(1)°, Z = 4, space group C2/c, R = 0.751 for 766 reflections with I > 2σ(I). The Zn atom in a molecule of the complex lies on a twofold axis and is coordinated at the vertices of a distorted tetrahedron by four N atoms of two HL ligands (average Zn-N distance 2.024 Å).     

Molecular structure of 2,3-(4′-phenylacetyl)- and 2,3-(4′-diphenylacetyl)-benzo-15-crown-5

The conformational state of two benzo-crown ethers with substantially different physiological activity, 2,3-(4-phenylacetyl)- and 2,3-(4-diphenylacetyl)benzo-15-crown-5, was studied in crystals and solutions in CH₃CN and CCl₄ by x-ray crystallographic analysis, IR spectroscopy, and conformational calculations by the method of molecular mechanics. Transition from the crystalline state to solutions was found to be accompanied by a substantial change in the conformation of the macrocyclic ring of all the compounds studied. The nature of the substituent in the benzene ring and the polarity of the solvent have an influence on the conformational state of the macrocyclic ring of the free ligand, which, however, is not the determining factor in the change in the activity of the compounds. The COCCOC fragments of the macrocyclic framework are conformationally labile, readily passing from gauche to trans conformations and the reverse, which is promoted by the negligible energy barriers between the different conformations, determined in the work by a molecular mechanics method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1819–1825, August, 1991.     

Synthesis and Spectral Characterization of Some Complexes Derived From N-Benzoyl-N′-Carboxylmethylthiopropylidine Thiourea (Bcmt)

Abstract

New metal complexes derived from the reaction of N-benzoyl-N′-carboxyl methylthiopropylidine thiourea (BCMT) with Cu(II), Co(II), Ni(II), and Fe(III) chloride and/or acetate salts have been synthesized and characterized using elemental analyses, molar conductance, spectral (IR, UV-Vis., mass, ¹H NMR), thermal (TGA, DTG), and magnetic measurements. The IR results showed the modes of coordination in case of mononuclear and binuclear metal complexes. Different types of geometries are suggested on the basis of the spectral and the magnetic data. Also, the ligand field parameters for the metal complexes were calculated. The amounts of the solvents as well as the mechanism of decomposition were proposed using thermal measurements. The results of biological activity of the ligand give us the promise to be effective in tumors treatment.     

Synthesis and Crystal Structure of Cu( Ⅱ ) Adduct with N-(4-Chlorophenyl)aza 15-Crown-5

The title compound C18 H25 NC4ClBr2Cu crystallizes in space group P 1 with a = 1.0105(2)nm b=1.0821(1) nm, c=1. 1007(2) nm, a=80. 00(1)°,β=80. 26(1)° γ=77. 83(1)°. Z=2, D = 1. 831 g/cm3, μ=62. 658 cm-1(Mok(?)). The final refinement converged to R=0. 031 for 2547 independent observed reflections. The complex molecule consists of two cationic moieties (HL)+ and an anion which appears as a bromide-bridged copper dimer (Cu2Br6)2-. This structural characterization seems to be rare in metal complexes with crown-ether.     

Molecular Structure of RbSCN Complex with N-(4′-hydroxy-3′,5′-diisopropylbenzyl)-monoaza-15-crown-5 Ether: Two Structures in a Unit Cell

Abstract

Molecular structures of the RbSCN complexes with N-(4′-hydroxy-3′,5′-diisopropylbenzyl)-monoaza-15-crown-5 ether (2-RbSCN) and N-(4′-hydroxy-3′,5′-di-tert-butylbenzyl)-monoaza-15-crown-5 ether (3-RbSCN) are reported. Crystal data (2-RbSCN) C₂₄H₃₉N₂O₅SRb, M = 553.11, monoclinic, space group P2₁, a = 9.835(4), b = 15.44(3), c = 18.563(6) Å, β = 99.58 (4), U = 2779(4) ų, Z = 4, Dc = 1.322 gcm^?3, v = 18.87 cm^?1, R = 0.047, Rw = 0.049 for the 5339 independent reflections (of 5712 measured reflections) and 590 parameters. (3-RbSCN) C₅₂H₈₆N₄ O₁₀S₂Rb₂, M = 1162.32, triclinic, space group P2₁, a = 9.917(2), b = 24.644(6), c = 12.572(3), α = 89.38(2), γ = 96.13(2), γ = 89.34(2) Å, U = 3054(1) ų, Z = 2, Dc = 1.264 g cm^?3, μ = 17.20 cm^?1, R = 0.051, R = 0.053 for the 6864 independent reflections (of 7201 measured reflections) and 316 parameters. The molecular structures of the RbSCN complexes with a series of N-(4-hydroxy-3′,5′-dialkylbenzyl)-monoaza-15-crown-5 ethers (1, 2 and 3) were systematically changed depending upon the size of the R groups at positions 3′ and 5′ in the side arm; 1 (R=Me), a polymer-like (1:1)_n complex; 2 (R = i-Pr), a mixture of 1:1 complex and polymer-like (1:1)_n complex; 3 (R = t-Bu), a dimeric 1:1 complex.     

Studies on Rare Earth Complexes with Crown Ether (ⅩⅩⅣ)——Synthesis and Characterization of Complexes of Lanthanide Isothiocyanates with Dibenzo-30-crown-10

Introduction The study of metal complexes with the crown ether is a quite interesting research field, but the research has mainly focused on the metal complexes with some crown ethers with a relatively small cavity such as 12-crown-4, 15-crown-5 and 18- crown-6 as well as their derivatives. Crown ethers with a larger cavity contain more oxygen atoms, so they have the ability to form the complexes of a higher co-     

Synthesis and thermal behaviours of side-chain liquid-crystalline poly[N-(4-methoxyazobenzene-4′-oxyalkyl)ethyleneimine]

A series of side-chain liquid-crystalline polymers, poly[N-(4-methoxyazobenzene- 4′-oxyalkyl)ethyleneimine](PEnZO), has been synthesised in which the number of methylene units in spacers varies from two to six. The structures of the synthesised monomers and polymers were confirmed by infrared (IR) and ¹H nuclear magnetic resonance (¹H NMR) spectroscopy. The thermal properties of these polymers have been investigated using differential scanning calorimetry (DSC), polarising optical macroscopic (POM) X-ray diffraction and thermogravimetric analysis (TGA). The test results indicated that the obtained polymers exhibited thermotropic liquid-crystalline mesomorphism of nematic type with schlieren textures. It was observed that the thermal behaviours of the polymers were strongly dependent on the degree of substitution and the length of spacers. Polymers containing less than 57% of mesogenic groups did not exhibit mesogenic phase and resembled amorphous polymer. A more pronounced odd–even effect in the melting points and their enthalpy changes was observed on increasing the spacer length in which the odd members displayed lower values, which were also slightly dependent on the substitution degree of polymers. The mesomorphic temperature ranges of odd members were wider than those of even members. The decomposition temperatures of copolymers were near 230°C.     

Synthesis,Spectral Studies and C-S,C-N Bond Fissions of Some Novel N-[Alkyl (4′- Substituted Phenylthio)] Phthalimides

N-[(4'-Substituted phenylthio)ethyl] phthalimide la-g and their corresponding n-propyl 2a-g, n-butyl 3a-g derivatives have been synthesised. The structure of these compounds were proved by UV,IR, ¹H NMR, ¹³CMR and mass spectra. The ¹H and ¹³C chemical shifts of the adjacent methylene protons and carbons of both the sulfur atom and phthalimido nitrogen group were reasonably correlated using σ° values. The carbon-nitrogen and the carbon-sulfur bond fissions in alkaline and acidic media were discussed.     

Concise Synthesis and Cellular Evaluation of 3′-Formyl-4′,6′-dihydroxy-2′-methoxy-5′-methylchalcone (FMC) and Its Analogues

3′-Formyl-4′,6′-dihydroxy-2′-methoxy-5′-methylchalcone (FMC) was a natural product isolated from Cleistocalyx operculatus. A four-step synthetic strategy toward FMC and its four analogues (1b–1e) was first developed. All compounds were synthesized from commercially available 2,4,6-trihydroxyacetophenone; formylation at 3′ position under Vilsmeier–Haack conditions was followed by the introduction of a methyl group at 5′ position. The key step of selective methylation at 2′ position was achieved by trimethylsilyldiazomethane (TMSCHN₂). Then substituted aromatic aldehydes were condensed through Claisen–Schmidt reaction in the presence of potassium hydroxide. All structures were confirmed by ¹H NMR, ¹³C NMR, and high-resolution mass spectra. FMC and analogues were screened for their antiproliferative activity.     

Potentiometric and Thermodynamic Studies of 5-(4′-Sulfonylazidophenylazo)-3-phenyl-2-thioxothiazolidin-4-one and Its Metal Complexes

The proton dissociation constant of 5-(4-sulfonylazidophenylazo)-3-phenyl-2-thio- xothiazolidin-4-one (SPT) and the stability constants of its complexes with some metal ions were calculated potentiometrically in 0.1 M KCl and 40% (v/v) ethanol–water mixture. The order of stability was found to be Mn²⁺ < Co²⁺ < Ni²⁺ < Cu²⁺ < Zn²⁺. The effect of temperature on the dissociation of SPT and the stability of its complexes were studied. The corresponding thermodynamic functions were derived and discussed. The dissociation process is unspontaneous, endothermic, and entropically unfavorable. The formation of the metal complexes was found to be spontaneous, endothermic and entropically favorable.     

(Mesitylene)ruthenium π-complexes with benzo-15-crown-5 and dibenzo-18-crown-6

The reactions of benzo-15-crown-5 and dibenzo-18-crown-6 with 1 equiv. of [(mes)Ru(MeNO₂)₃]²⁺ (mes = 1,3,5-C₆H₃Me₃) give the mononuclear complexes [(mes)Ru(η⁶-benzo-15-crown-5)]²⁺ (1) and [(mes)Ru(η⁶-dibenzo-18-crown-6)]²⁺ (2) in 50% yield. Similar reaction with 2 equiv. of [(mes)Ru(MeNO₂)₃]²⁺ produces the dinuclear complex [(μ-η⁶:η⁶-dibenzo-18-crown-6)Ru₂(mes)₂]⁴⁺ (3) in 96% yield as a 2:3 mixture of cis- and trans-isomers. Structures of 2(OTf)₂ and trans-3(OTf)₄ were confirmed by X-ray diffraction. The NMR titration showed that mononuclear dications 1 and 2 bind Na⁺ ion less effective (K_a = 600 and 250 M^-1) than free benzo-15-crown-5 and dibenzo-18-crown-6 (K_a = 2 × 10⁵ and 5 × 10⁶ M⁻¹). The dinuclear tetracation 3 does not bind Na⁺ within measurable limits of NMR titration method. The electrochemical behaviour of complexes 1-3 was studied in propylene carbonate solution. They exhibit a partially chemically reversible Ru(II)/Ru(I) reduction, which in the case of the dinuclear complex 3 proceeds through two slightly separated steps. The redox activity of the complexes is substantially unaffected by the presence of sodium ion.