Novel polyurethanes with macroheterocyclic (crown-ether) structures in the polymer backbone

The synthesis of a functionalized crown ether was accomplished in two steps by condensing 3,4-dihydroxybenzaldehyde with bis(2-chloroethyl)ether and subsequent reduction of the reaction product, bis(formylbenzo)-18-crown-6 (4) to a diol (5). Polyurethanes that bear the dibenzo-18-crown-6 moiety in the polymer backbone were synthesized from bis(methylolbenzo)-18-crown-6 (5), a polypropylene glycol, and methylene bis(4-cyclohexyl isocyanate). The resulting polymers were fibrous white solids with glass transitions from ca. 15–120°C, depending on the starting diol composition. The thermomechanical spectra of melt pressed or solvent cast films of several crown-ether-bearing polyurethanes showed evidence of multiphase character. The polymers failed to complex effectively with sodium ions. However, their complexing ability with potassium ion was similar in magnitude to that observed with relatively simple crown ethers.     

Stability of Complexes of NH4 + with 18-Crown-6, Dicyclohexyl-18-Crown-6, Dibenzo-18-Crown-6 and Dibenzo-24-Crown-8 in Water Saturated Nitrobenzene

From extraction experiments with ²²Na tracer, the exchange extraction constants corresponding to the NH₄ ⁺(aq) + NaL⁺ (nb)NH₄L⁺(nb) + Na⁺ (aq) equilibrium taking place in the two-phase water-nitrobenzene system (L = 18-crown-6, dicyclohexyl-18-crown-6, dibenzo-18-crown-6 and dibenzo-24-crown-8; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the NH₄L⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the order dibenzo-24-crown-8 (DB24C8) < dibenzo-18-crown-6 (DB18C6) < dicyclohexyl-18-crown-6 (DCH18C6) < 18-crown-6 (18C6).     

Sodium and potassium benzeneazophosphonate complexes with crown ethers: Solid-state microwave synthesis, characterization and biological activity

The eco-friendly synthesis, spectroscopic (IR, MS, ¹H and ¹³C NMR) study and biological (cytostatic, antiviral) activity of sodium and potassium benzeneazophosphonate complexes, obtained by reaction in the solid state under microwave irradiation of the alkali salts of ethyl [α-(4-benzeneazoanilino)-N-benzyl]phosphonic acid and [α-(4-benzeneazoanilino)-N-4-methoxybenzyl]phosphonic acid with crown ethers containing 18-membered (dibenzo-18-crown-6 and bis(4′-di-tert-butylbenzo)-18-crown-6), 24-membered (dibenzo-24-crown-8) and 30-membered (dibenzo-30-crown-10) macrocyclic rings, have been described. The simple work-up solvent free reaction is an efficient green procedure for the formation of mononuclear crown ether complexes in which the sodium/potassium ion is bound to oxygen atoms of the macrocycle and the phosphonic acid oxygen. The free crown ethers, alkali benzeneazophosphonate salts and their complexes were evaluated for their cytostatic activity in vitro against murine leukemia L1210, murine mammary carcinoma FM3A and human T-lymphocyte CEM and MT-4 cell lines, as well as for their antiviral activity against a wide variety of DNA and RNA viruses. The investigated compounds showed no specific antiviral activity, whereas all the free crown ethers and their complexes demonstrated cytostatic activity, which was especially pronounced in the case of bis(4′-di-tert-butylbenzo)-18-crown-6 and its complexes.     

[La2I2(OH)2(Dibenzo-18-Krone-6)2]I(I3), ein kationischer,dimerer in-cavity-Komplex mit Iodid und Triiodid als Anionen

[La₂I₂(OH)₂(dibenzo-18-crown-6)₂]I(I₃), a Cationic Dimeric in-cavity Complex with Iodide and Triiodide as Anions Single crystals of [La₂I₂(OH)₂(dibenzo-18-crown-6)₂]I(I₃) are obtained from the reaction of LaI₃ and dibenzo-18-crown-6 in acetonitrile. The crystal structure monoclinic, C2/m, Z = 4, T = 293 [100] K, a = 2179(3) [2162.3(3)], b = 1070.3(3) [1069.6(1)], c = 1118.2(3) [1110.6(1)] pm, β = 93.1(1) [92.83(1)]°, R1 = 0.0601 [0.0411], wR2 = 0.1449 [0.1014] contains hydroxide-bridged cationic dimers and iodide as well as triiodide as anions.     

Novel fluorinated polymer from 18-crown-6 by radical polyaddition

Radical polyaddition of bis(α-trifluoromethyl-β,β-difluorovinyl) terephthalate [CF₂C(CF₃)OCOC₆H₄COOC(CF₃)CF₂] (BFP) with 18-crown-6 to produce fluorinated polymer bearing crown ether moiety in main chain is described. Prior to polyaddition, the model reaction of 2-benzoxypentafluoropropene [CF₂C(CF₃)OCOC₆H₅] (BPFP) with 18-crown-6 was investigated to afford suitable reactions condition for polyaddition. The polyaddition of BFP with 18-crown-6 yielded a soluble polymer bearing M_n=5.5×10⁴ with unimodal molecular weight distribution after purification by reprecipitation with cold ethanol.     

Complexes of sodium and lithium borohydrides with macrocyclic polyethers

A method for the synthesis of complexes of sodium and lithium borohydrides with crown ethers is proposed. The complexes of sodium borohydride with benzo-15-crown-5, 4′-aminobenzo-15-crown-5, dibenzo-18-crown-6, and diaza-18-crown-6 and the complexes of lithium borohydride with benzo-15-crown-5 and dibenzo-18-crown-6 are synthesized. These complexes can be used for the preparation of hydrogen in their reactions with methanol. The complex formation does not affect the purity of hydrogen formed.     

Preparation and crystal structure of bis(dibenzo-18-crown-6)-(tetrachlorocuprato(II)-Cl,Cl′, Cl″, Cl‴)dipotassium diaqua(dibenzo-18-crown-6)potassium dichlorocuprate(I)-dibenzo-18-crown-6

New mixed complex compound bis(dibenzo-18-crown-6)(tetrachlorocuprato(II)-Cl, Cl′, Cl″, Cl?) dipotassium diaqua(dibenzo-18-crown-6)potassium dichlorocuprate(I)dibenzo-18-crown-6 [(CuCl₄)[K(Db18C6)]₂]·[K(Db18C6)(H₂O)₂]⁺·[CuCl₂]^?·Db18C6 was prepared and its structure was studied by the X-ray structural analysis. The structure was found to be disordered. The asymmetric part of its unit cell contains 1/4 of each of its four components. For a given [CuCl₄]^2? anion its Cu²⁺ cation is disordered over two equally probable positions and its independent Cl atom is disordered over three positions differing by occupancy. In this structure two [K(Db18C6)]⁺ fragment of the complex molecule and the complex cation [K(Db18C6)(H₂O)₂]⁺ are of guest-host type with K⁺ cation as the guest. In this structure the statistically disordered alternating cations and Db18C6 molecules form infinite chains. The statistically disordered [CuCl₂]^? anions also form infinite chains.     

Synergistic extraction of americium(III) with 2-thenoyltrifluoroacetone and crown ethers

Extracton, of Am³⁺ in benzene with 2-thenoyltrifluoroacetone (HTTA) and crown ethers (CEs) such as 15-crown-5, 18-crown-6, dicyclohexano-18-crown-6, dibenzo-18-crown-6, dicyclohexano-24-crown-8, and dibenzo-24-crown-8 was investigated. Synergistic effect by CE was observed regardless of the kind of CE examined. The extracted species was found to be Am(TTA)₃(CE), and adduct formation constants between Am(TTA)₃ and CE in the organic phase were determined. The sequence of constant could not be explained only by basicity of CE and the steric effect of CE should be taken into account to elucidate the adduct complex formation.     

Syntheses of diaza-18-crown-6 ligands containing two units each of 4-hydroxyazobenzene,benzimidazole, uracil,anthraquinone, or ferrocene groups

Six new diaza-18-crown-6 ligands each containing two aromatic side arms with responsive functions were prepared. Diaza-18-crown-6 containing two 4-hydroxyazobenzene ( 3 ) or two 4 -hydroxy- 4′ -(dimethyl-amino)azobenzene ( 4 ) substituents were prepared via a one-pot Mannich reaction. Diaza-18-crown-6 containing two benzimidazole ( 5 ), two uracil ( 6 ) or two 9,10-anthraquinone ( 7 ) substituents were prepared by treating the diazacrown with the appropriate chloromethyl-containing compound. Reductive amination using sodium triacetoxyborohydride, diaza-18-crown-6 and ferrocenecarboxaldehyde was used to prepare bisferrocene-substituted diaza-18-crown-6 ( 8 ). Interactions of compounds 3 , 5 , and 6 with Na⁺, K⁺, Ba²⁺, Ag⁺, and Cu²⁺ were evaluated by a calorimetric titration technique at 25° in methanol. All three ligands form more stable complexes with Ag⁺ and Cu²⁺ ( 5 forms a precipitate with Ag⁺) than with Na⁺ and K⁺. Ligand 5 also forms a highly stable complex with Ba²⁺.     

On the protonation of dibenzo-18-crown-6

Abstract  

The stability constant of the dibenzo-18-crown-6·H₃O⁺ cationic complex species dissolved in nitrobenzene saturated with water has been determined from extraction experiments in the two-phase water–nitrobenzene system and from γ-activity measurements. Various structures of protonated dibenzo-18-crown-6 are discussed.     

Über das Fluoreszenzthermochrome Acetonitrilo-Kupferjodid mit Dibenzo-18-Krone-6

About the Fluorescence Thermochromism of Acetonitrile Copper Iodide with Dibenzo-18-Crown-6 Copper iodide reacts in actonitrile solution with dibenzo-18-crown-6 to form a compound,(CuJ)₄(CH₃CN)₄(db-18-c-6), which fluoresces yellow at 298K, but pink at 77 K. It decomposes at 55.3°C. (5 Torr) by lost of acetonitrile and a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a solvate CuJ. CH₃CN. It also shows fluorescence thermochromism (yellow at 298 K, but green at 77 k) but decomposes at 0°C and 760 Torr. The luminescences pectra of the macrocyclic polyether complex at 298 K is redshifted. This probably results from intersection between the crown and the acetonitrile copper iodide.     

Differential pulse polarographic studies of mercury complexes with some crown ethers in nonaqueous solvents

The complex formation of Hg(2+) with some macrocyclic crown ethers in nitrobenzene, acetonitrile and dimethylformamide solutions was studied by differential pulse polarography at 25 degrees C. The stoichiometry and stability of the complexes were determined by monitoring the shift in the Hg(2+) differential pulse peak potential against the ligand concentration. The stability of the resulting 1:1 complexes vary in the order dicyclohexyl-18-crown-6 > 18-crown-6 > 15-crown-5 > dibenzo-18-crown-6 > dibenzo-24-crown-8 > benzo-15-crown-5 > 12-crown-4. There is an inverse relationship between the complex stability and the Gutmann donor number of solvents.     

Synthesis and reaction of polymers bearing 5-membered cyclic dithiocarbonate group

5-(Methacryloyloxy)methyl-1,3-oxathiolane-2-thione ( 3 ) was synthesized from glycidyl methacrylate (GMA) and carbon disulfide in the presence of lithium bromide in 93% yield. The radical polymerization of 3 in DMSO initiated by AIBN at 60°C afforded corresponding polymethacrylate 4 quantitatively. Copolymerization of 3 with MMA was also carried out. 5-Phenoxymethyl-1,3-oxathiolane-2-thione ( 6 ), model dithiocarbonate, reacts with benzylamine at room temperature to afford O-(1-mercapto-3-phenoxy-2-propyl)N-benzyl-thiocarbamate ( 7 ) and 1,1′-dithiobis[3-phenoxy-2-(benzylaminothiocarbonyloxy)-propane] ( 8 ) in 89% and 7% yield, respectively. Polymer 4 reacted with butylamine or dipropylamine to afford a corresponding polymethacrylate bearing thiol group, which immediately turned to insoluble gel by facile auto-oxidation of the thiol group. © 1995 John Wiley & Sons, Inc.     

Interaction of ferrocenecarbaldehyde with zinc tetrahydroborate and its derivatives

Ferrocenecarbaldehyde was reduced to methylferrocene upon interaction with zinc tetrahydroborate in THF. The reactions proceeded rapidly (5–10 min) in high yields (ca. 90%). Analogous results were obtained when a mechanically activated mixture of zinc chloride and sodium tetrahydroborate or the complex of zinc tetrahydroborate with dibenzo-18-crown-6, 2Zn(BH₄)₂·DB-18-C-6, was used in the reaction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 214–216, January, 1999.     

Column chromatographic separation of thorium(IV) from ascorbic acid medium using poly-(dibenzo-18-crown-6)

A simple separation method has been developed for thorium(IV) using poly-(dibenzo-18-crown-6) and column chromatography. The separation was carried out from ascorbic acid medium. The adsorption of thorium(IV) was quantitative from 0.001-0.01M ascorbic acid. The elution of thorium(IV) was quantitative with 4.0-8.0M HCl, 3.0-6.0M HClO₄, 4.0-8.0M H₂SO₄ and 1.0-8.0M HBr. The capacity of poly-(dibenzo-18-crown-6) for thorium(IV) was found to be 1.379±0.01 m^.mol/g of crown polymer. Thorium(IV) was separated from a number of cations in binary as well as in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand. It is possible to separate and determine 5 ppm of thorium(IV) by this method. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%).     

Ion-pair extraction of tetravalent plutonium from hydrochloric acid medium using crown ethers

Ion-pair extraction behaviour of plutonium (IV) from varying concentrations of HCl solution was studied employing crown ethers (benzo-l5-crown-5 (B15C5), 18-crown-6, (18C6), dibenzo-18-crown-6 (DB18C6), dicyclohexano-18-crown-6, (DC18C6), dibenzo-24-crown-8 (DB24C8) and dicyclohexano-24-crown-8 (DCH24C8)) in nitrobenzene as the extractant. Ammonium metavanidate was used as the holding oxidant in the aqueous phase and the conditions necessary for the quantitative extraction of the tetravalent ion were found. The co-extraction of species of the type [HL⁺].[HPu(Cl) ₆ ^– ] and [HL⁺]2·[Pu(Cl) ₆ ^2– ] as ion-pairs (where L represents the crown ether) is suggested.     

Column chromatographic separation of thorium (IV) from associated elements using poly-(dibenzo-18-crown-6) from sodium nitrate medium

A simple column chromatographic method has been developed for the separation of thorium from associated elements using poly-(dibenzo-18-crown-6). The separations are carried out from sodium nitrate medium. The adsorption of thorium was quantitative from 0.1-0.5M sodium nitrate. Amongst the various eluents tested, 1.0-8.0M HCl, HBr, H₂SO₄ and 3.0-8.0M HClO₄ were found to be particularly efficient for e elution of thorium. The capacity of poly-(dibenzo-18-crown-6) for thorium was found to be 1.034 mmole/g of crown polymer. Thorium was arated from number of elements in binary mixtures in which most of the elements showed a very high tolerance limit. It was possible to separate tium from a number of elements in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand and ga: artles. The method is very simple, rapid, selective and has good reproducibility (approximately±2%).     

Kationische und anionische kantenverknüpfte Dimere in [Dy2(Dibenzo-18-Krone-6)2Cl4][Dy2(CH3CN)2Cl8]. Synthese und Kristallstruktur

Cationic and Anionic Edge-Connected Dimers in [Dy₂(dibenzo-18-crown-6)₂Cl₄][Dy₂(CH₃CN)₂Cl₈]. Synthesis and Crystal Structure Colourless single crystals of 2 DyCl₃ · dibenzo-18-crown-6 · CH₃CN are obtained upon reaction of DyCl₃ or KDy₂Cl₇ with dibenzo-18-crown-6-ether in acetonitrile. The crystal structure (triclinic, P1 , Z = 2; a = 1 105.6(2); b = 1 144.5(3); c = 1 367.8(3); α = 93.46(1); β = 92.27(1); γ = 117.45(1); R = 0.046; R_w = 0.033) contains cationic and anionic edge-connected dimers according to [Dy₂(dibenzo-18-crown-6)₂Cl₄]²⁺ [Dy₂(CH₃CN)₂Cl₈]²⁺ where Dy1 and Dy2 are coordinated by 3 and 5 chloride ions, respectively.     

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 characterization of trans-di(nitrobenzo)- and di(aminobenzo)-18-crown-6 derivatives with high selectivity

The dibenzo-18-crown-6 derivatives such as di(nitrobenzo)-18-crown-6 and di(aminobenzo)-18-crown-6 were synthesized by nitration reaction and catalytic hydrogenation with high selectivity. The chemical structures were determined by FTIR, ¹H NMR, ¹³C NMR, and UV. Regarding the mixture of Ac₂O and HNO₃ as nitrating agent, the reaction exhibited commendable trans-isomer selectivity. Effects of nitrating agent ratio, reaction temperature and reaction time on yield of trans-di(nitrobenzo)-18-crown-6 were investigated. The yield of trans-di(nitrobenzo)-18-crown-6 was 62.9% for nitrating agent ratio of 1/1, reaction temperature of 50?°C and reaction time of 5?h. Moreover, effect of reaction time on trans-di(aminobenzo)-18-crown-6 was also studied.