Synthesis of Bis(2,2-benzimidazolyl)dibenzo-18-crown-6

A method has been developed for the introduction of benzimidazole substituents into the dibenzo-18-crown-6 molecule by condensation of its 4′,4″(5″)-diacetyl derivative with ortho-phenylenediamine. Increasing the length of the hydrocarbon chain of the acyl substituent or replacing Ac by CSNH₂ led to a decrease in the yield of the desired product. No product was formed when Ac was replaced by COOH or CN. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1388–1390, September, 2005.     

二环己基并18冠6的制备方法

二苯并-18－冠-6;二环己基并18冠6的制备方法     

微波辅助二苯并-18-冠-6的合成

以邻苯二酚与二甘醇二取代物为原料,氢氧化钾为碱和模板剂,在微波辅助下,采用“一锅煮”法合成二苯并-18-冠-6。 经单因素及正交实验考察了原料、溶剂、时间、温度和功率对反应收率的影响,获得了最佳的工艺条件：以邻苯二酚与二氯乙醚为原料,二甲亚砜为溶剂,反应温度70 ℃,时间60 min,功率500 W,收率可达46.3%。     

吖啶基功能化二苯并-18-冠-6的合成

通过改变离去基团的活性、亲核试剂、溶剂的极性、离子性及反应温度等,对传统的U llm ann合成法进行了优化,将二苯并-18-冠-6进一步功能化,合成了未见文献报道的N,N′-二-(9-吖啶基)-4,4′-二氨基二苯并-18-冠-6,收率在87%以上。其结构经1H NMR,IR及元素分析表征。     

Syntheses of dibenzo-18-crown-6 lariat isomers and their complexation with lanthanoid nitrates

Two constitutional isomers of dibenzo-18-crown-6 derivatives (6 and 7) were synthesised and their binding behaviours towards trivalent lanthanoid cations (La^3 + , Ce^3 + , Pr^3 + , Nd^3 + , Sm^3 + , Eu^3 + , Gd^3 +  and Tb^3 + ) were investigated. Both isomers expressed better binding affinities towards Sm^3 +  and Tb^3 +  than a group of other lanthanoids, as measured by the ligand-to-metal charge-transfer (LMCT) band intensity at ca. 425 nm using UV–vis spectroscopic method. Additionally, the trans isomer 7 was shown to have a higher binding ability than the cis isomer 6 towards Tb^3 + .

     

顺、反异构的二羟基二苯并-18-冠-6的方便合成

用顺、反二氨基二苯并－18－冠－6与氟硼酸和亚硝酸正戊酯反应制得相应的芳基重氮氟硼酸盐，经水解，以较好的收率制得了二羟基二苯并－18－冠－6，后者是合成功能高分了的有用单体。     

Hydration of complexes of 18-crown-6 with potassium nitrate or potassium picrate in the polymer phase

Adsorption of water vapor by granular polymer based on dibenzo-18-crown-6 and containing potassium nitrate or potassium picrate in the polymer phase was studied by the isopiestic method at 298 K. The adsorption of water vapor is described by isotherms corresponding (according to BDDT classification) to polymolecular absorption with a high adsorptive potential. In terms of the Aranovich model of polymolecular absorption, the monolayer capacity and differential heat of adsorption were calculated, and the stoichiometry of hydration of the potassium nitrate and potassium picrate complexes with immobilized crown ether was estimated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1940–1942, October, 1998.     

Dibenzo-18-crown-6 modified with kojic acid fragments

Diazonium salts were prepared by diazotization of 4′-amino-, 4′,4″-, and 4′,5″-diaminodibenzo-18-crown-6. Their coupling products with kojic acid (5-hydroxy-2-hydroxymethyl-γ-pyrone) were synthesized for the first time: 4′-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-, 4′,4″-di-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-, and 4′,5″-di-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-dibenzo-18-crown-6. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 415–416, September–October, 2006.     

New Derivatives of Dibenzo-18-crown-6 with Salsolidine and Salsoline Fragments

New derivatives of dibenzo-18-crown-6 were prepared by condensing 4,4(5)-dibenzo-18-crown-6-dicarboxylic acid dichloride with salsolidine and salsoline. The structures of these compounds were proved by PMR and IR spectral methods.     

Crystal structure of supramolecular complexes formed by 18-crown-6 andcis-anti-cis-dicyclohexano-18-crown-6 (host) with 3,4-diaminofurazane (guest)

An X-ray—diffraction study is reported for two molecular complexes containing 3,4-diamino-1,2,5-oxadiazole as guest (G) with 18-crown-6 (18-C-6) andcis-anti-cis-dicyclohexano-18-crown-6 (DCH-6B) as host. Both complexes are of the polymeric-chain structure with the guest molecule bridging two crown neighbours. ComplexI: [18-C-6*G*H₂O], 111, monoclinic,P2₁/n,a=8.171(1),b=15.042(2),c=16.209(6) Å, =101.15(2)°, finalR-factor 0.068. ComplexII: [DCH-6B*G], 11, monoclinicC2/c,a=21.212(4),b=9.380(2),c=13.049(3) Å, =108.61(3)°, finalR 0.047.     

Structure of 〔Na(DB18C6) (CH_3OH)〕_2W_6O_(19)·(DB18C6)·(CH_3OH)

1INrnODUCTIoNlnthepreviouspapers,wehavereportedthesynthesisandcrystalstructureofseveralcrownetherpolyoxometalates"-",nowwestudythestructureofthetitlecomplexandcompareitwithsomeothercrownetherpolyoxometalatecomplexes.2EXPERmENTALToal5OmLaqueoussolutioncontaining32g(1OOmol)Na,WO#.2H,Opre-justedtopH=3.5withchloricacid,14g(4Ommol)(n-Bu)'NBrwasadded,thenwhitepowderwasformed.ThewhiteprecipitateobtainedwithafiltrationwaskeptasthenewmaterialAinnextstep.AmixtureoflgAandO.3g(O.8mmol)DB18…     

Electrosyntheses of free-standing poly(dibenzo-18-crown-6) films in boron trifluoride diethyl etherate on stainless steel electrode

High-quality free-standing poly(dibenzo-18-crown-6) (PDBC) films with a conductivity of 4.1 × 10⁻² S cm⁻¹ and good thermal stability were synthesized electrochemically on stainless steel electrode by direct anodic oxidation of dibenzo-18-crown-6 (DBC) in pure boron trifluoride diethyl etherate (BFEE). In this medium, the oxidation potential onset of DBC was measured to be only 0.98 V vs. SCE, which was much lower than that in acetonitrile + 0.1 mol L⁻¹ Bu₄NBF₄ (1.45 V vs. SCE). PDBC films obtained from this medium showed good redox activity and stability in BFEE. The structural characterization of PDBC was performed using UV-vis, FTIR spectroscopy. The results of quantum chemistry calculations of DBC monomer and FTIR spectroscopy of PDBC films indicated that the polymerization mainly occurred at C₍₄₎ and C₍₅₎ positions). Fluorescent spectral studies indicated that PDBC was a blue light emitter. To the best of our knowledge, this is the first report on the electrodeposition of free-standing PDBC films.     

Synthesis and crystal structure of aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(perchlorato-O)potassium perchlorate

A new compound, aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(perchlorato-O)potassium perchlorate ([K(DB18C6)(H₂O)]⁺ · [K(ClO₄)(DB18C6)] · ClO ₄ ^? ; compound I) is synthesized and studied by X-ray crystallography. The crystals are triclinic: a = 9.050 Å, b = 9.848 Å, c = 26.484 Å, α = 82.87°, β = 84.16°, γ = 77.93°, Z = 2, space group P $\bar 1$ . The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.058 for 5960 independent reflections (CAD4 diffractometer, λMoK _α radiation). A complex cation [K(DB18C6)(H₂O)]⁺ and a complex molecule [K(ClO₄)(DB18C6)] are of the host-guest type; they are linked into a dimer through two K⁺ → π(C) bonds formed by one of the two K⁺ cations with two C atoms of the benzene ring of the DB18C6 ligand from the adjacent complex. Both DB18C6 ligands in I have a butterfly conformation with approximate symmetry C _2v .     

Dibenzo-18-crown-6 diaqua(dibenzo-18-crown-6)potassium triiodide: Synthesis and crystal structure

A new compound, dibenzo-18-crown-6 diaqua(dibenzo-18-crown-6)potassium triiodide [K(Db18C6)(H₂O)₂)⁺ · I₃⁻ · Db18C6 (I), is synthesized and studied by X-ray crystallography. The crystals of compound I are orthorhombic: a = 22.065 ?, b = 22.140 ?, c = 9.433 ?, Z = 4, space group Pccn. Structure I is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 for all 5974 unique reflections. Structure I contains the following asymmetric units: a half of the I₃⁻ centrosymmetric anion and two halves of the mixed equally average [K(Db18C6)(H₂O)₂]⁺ host—guest complex cation (a) and a free Db18C6 molecule, each stacked on the axes 2 of the perpendicularly averaged plane of the eighteen-membered macroheterocycle. In complex I, both Db18C6 molecules (a and b) have a “butterfly” conformation with approximate symmetry C _2v . Original Russian Text ? A.N. Chekhlov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 3, pp. 516–520.     

Synthesis and Crystal Structure of 3,3＇-Dimethyl-dibenzo-18-crown-6

1 INTRODUCTION Since the report about unusual coordination num- bers and arrangements to metal ions of crown ether compounds by Pedersen[1], the crown ether compounds have attracted much attention. Due to their novel coordination modes, crown ethers have been widely used in catalyst, solvent extraction, iso- tope separation, bionics, material chemistry, host- guest chemistry and supramolecular chemistry[2~5]. So it is vital to study the synthesis of new crown ethers and their crystal stru…     

Acylation of Dibenzo-18-crown-6 with Alkali-metal Acetates in Polyphosphoric Acid

The acylation of dibenzo-18-crown-6 by lithium, sodium, and potassium acetates in polyphosphoric acid was studied. Complexes of dibenzo-18-crown-6 with the acetates were obtained. A new method is proposed for the production of mono- and diacetyldibenzo-18-crown-6 by the reaction of dibenzo-18-crown-6 complexes with metal acetates in polyphosphoric acid. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1146–1149, August, 2005.     

Neutral molecule/crown ether interactions 5. Comparison of the C−H acidic interactions of nitromethane and acetonitrile with 18-crown-6 and dibenzo-18-crown-6. Crystal structures of dibenzo-18-crown-6·2 CH3NO2 and dibenzo-18-crown-6·2 CH3CN

Complete structural characterization of dibenzo-18-crown-6·2 CH₃NO₂ and dibenzo-18-crown-6·2 CH₃CN have been carried out, including location and refinement of the methyl hydrogen atoms. Dibenzo-18-crown-6·2 CH₃NO₂ is monoclinic,P2₁/c, with (at –150°C)a=9.573(2),b=14.636(2),c=33.471(7) Å, =93.77(2)°, andD _calc=1.37 g cm^–3 forZ=8. Interactions between the solvent methyl groups and the crown ethers and other solvent nitro groups associate the 1 : 2 complexes into polymeric chains alongb. The acetonitrile adduct exists as discreet 1 : 2 complexes in the solid state with C–H...O interactions exlusively to the ether. This complex is triclinic,P 1, with (at –150°C)a=9.458(6),b=9.570(5),c=14.404(5) Å, =73.18(4), =79.85(5), =66.82(6)°, andD _calc=1.28 g cm^–3 forZ=2. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82070 (22 pages).For part 4, see reference [1].     

Synthesis and crystal structure of aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)-(tetrachlorocuprato(II)-Cl)potassium

New mixed complex compound aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(tetrachlorocuprato(II)-Cl)potassium, [K(CuCl₄)(Db18C6)]^? · [K(Db18C6)(H₂O)]⁺, is synthesized and its crystal structure is studied by the method of x-ray structural analysis. The structure includes two independent complex ions, both of guest-host type: two cations K⁺ are located in the respective cavities of the Db18C6 crown-ligand (one in each) and each is coordinated by all its six O atoms and one Cl atom of the anion-ligand [CuCl₄]^2? or O atom of the ligand water molecule. Coordination of these two K⁺ cations is completed to hexagonal pyramidal one by formation by each of unusually weak coordination bond K⁺ → π(\(C\dddot - C\)) with two C atoms of respective benzene ring in the neighboring Db18C6 ligand. In this crystal structure the complex anions and cations form dual infinite chains via these coordination bonds and interionic O-H?Cl hydrogen bonds.     

Synthesis and crystal structure of dibenzo-18-crown-6 oxonium perchlorate

An ionized crystalline adduct of dibenzo-18-crown-6, perchloric acid, and water (H₃O)[DB 18K6](ClO₄) is synthesized and structurally studied by X-ray diffraction. The crystals are triclinic: a = 8.582 Å, b = 10.486 Å, c = 26.293 Å, α = 79.45°, β = 82.00°, γ = 79.36°, Z = 4, space group P \(\bar 1\). The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 for 5936 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). The structure contains two independent DB18C6 molecules, two independent H₃O⁺ ions, and two independent ClO ₄ ^? ions. The H₃O⁺ ions each lie in the cavity of each of the two DB18C6 molecules and are retained there by three strong hydrogen bonds. Two DB18C6 molecules have close geometric parameters and a butterfly conformation with approximate symmetry C _2v . One of the two independent ClO ₄ ^? anions is disordered over two orientations.     

Application of affinity capillary electrophoresis and density functional theory to the investigation of benzo-18-crown-6-ether complex with ammonium cation

Affinity capillary electrophoresis (ACE) and quantum mechanical density functional theory (DFT) calculations have been employed for investigation of non-covalent interactions between macrocyclic ligand, benzo-18-crown-6-ether (B18C6) and ammonium cation, NH₄⁺. Firstly, by means of ACE, the strength of the B18C6-NH₄⁺ complex in mixed binary hydro-organic solvent system, methanol–water (50/50, v/v), was determined from the dependence of effective electrophoretic mobility of B18C6 (corrected to reference temperature 25 °C and constant ionic strength, 10 mM) on the concentration of ammonium ion in the background electrolyte (BGE) using non-linear regression analysis. The logarithmic form of the apparent binding (stability) constant (log K_b) of B18C6-NH₄⁺ complex in the above binary solvent system was found to be equal to log K_b = 1.63 ± 0.10. Secondly, the structural characteristics of B18C6-NH₄⁺ complex were described by quantum mechanical density functional theory (DFT) calculations. According to these calculations, in the energetically most favoured form of the B18C6-NH₄⁺ complex, three strong hydrogen bonds are formed between central ammonium ion and B18C6 ligand, one of them is directed to aryl-O-alkyl (Ar–O–CH₂) ethereal oxygen and the other two hydrogen bonds are oriented to alkyl-O-alkyl (CH₂–O–CH₂) ethereal oxygen atoms of the macrocyclic crown ligand.