نتایج جستجو برای: crown complexes
تعداد نتایج: 155290 فیلتر نتایج به سال:
Treatment of 3,5-diisopropyltriazole, 3,5-diphenyltriazole, 3,5-di-3-pyridyltriazole, phenyltetrazole, pyrrolidinyltetrazole, or tert-butyltetrazole with equimolar quantities of potassium hydride and 18-crown-6 in tetrahydrofuran at ambient temperature led to slow hydrogen evolution and formation of (3,5-diisopropyl-1,2,4-triazolato)(18-crown-6)potassium (88%), (3,5-diphenyl-1,2,4-triazolato)(t...
Complex formation between the silver(I) ion and monoazaand diaza-crown ethers has been studied in five polar, nonaqueous solvents using potentiometric techniques. The stability constants are spread over seven orders of magnitude, and the major contributor to this variation is the solvation of the silver(I) cation. The ring-size dependence of the stability constants is determined both by the cor...
The pH-profiles of the extraction of Cs(+) into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been d...
The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12-crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation cons...
A novel 1,2-dithiolate ligand, that is, the 2-(trifluoromethyl)acrylonitrile-1,2-dithiolate, abbreviated here as tfadt, is prepared from the corresponding cyclic dithiocarbonate. This ligand, substituted with both a CN and a CF(3) group, is compared with the well-known maleonitrile- and bis(trifluoromethyl)ethane-1,2-dithiolates. The preparation, electrochemical properties, and X-ray crystal st...
Synthesis of phosphinite complexes 12-14a-c, 15a and 16a was achieved via reaction of transient Li/Cl phosphinidenoid complexes 6-10, prepared from dichloro(organo)phosphane complexes [(OC)5M{RPCl2}] 1-5 (1,6: R = CPh3, 2,7: R = C5Me5, 3-5, 8-10: R = CH(SiMe3)2, 1-3, 6-8: M = W, 9: M = Mo, 10: M = Cr), with different alcohols 11a-c (a: R = allyl, b: R = methyl, c: R = isopropyl). Deprotonation ...
The reaction of Pb[BF(4)](2) in H(2)O/MeCN solution with the macrocycle 18-crown-6 gave the dinuclear complex [{Pb(18-crown-6)(H(2)O)(μ(2)-BF(4))}(2)][BF(4)](2), containing two nine-coordinate lead centres, each bound to all six oxygens of a crown ligand, one water molecule and bridged by two μ(2)-BF(4) groups. In contrast, the oxa-thia crown [18]aneO(4)S(2) gave the mononuclear [Pb([18]aneO(4)...
The present study was carried out by focusing on the interaction between molecular complexes crown and thiacrown ethers such as 15-crown-5 (15C5), thia-15-crown-5 (T15C5), dithia-15-crown-5 (DT15C5) with homogeneous and heterogeneous dihalogens (XY) such as I2, IBr, ICl, Br2, Cl2 in the gas phase and in dichloromethane solvent through applying density function theory (DFT) as well as Gaussian 9...
Diazahexathia-24-crown-8 (2) has been isolated from the reaction mixture during the preparation of monoazatrithia-12-crown-4 (1). When N-Boc protected bis(2-chloroethyl)amine was employed as a starting material, N-Boc protected monoazatrithia-12-crown-4 (3) and N-Boc protected diazahexathia-24-crown-4 (4) were separated easily. Double-armed diazahexathia-24-crown-8 having two 3',5'-dichlorobenz...
Single-crystal X-ray analysis of the 5'-bromo-l',3'-xyly~-l8-crown-5* tert-butylammonium hexafluorophosphate complex shows that the complex is of the "nesting" type in which the cation and the aryl group are on the same face of the macroring and that the macroring has a (ag'a)(ag-a)lag'a)(ag-a)(ag'a)lag-a) eonformation. Among crown ethers with aryl-sub-units, 1' ,3'-xylyl crown ethers (1) have ...
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