نتایج جستجو برای: 15 crown 5
تعداد نتایج: 1572103 فیلتر نتایج به سال:
The synthesis of some thio-oxocrown ether ligands, B1 (1,4-dithio-12-crown-4), B2 (1,7-dithio-12-crown-4), B3 (1,7-dithio-15-Crown-5), B4 (1,7-dithio-18-crown-6), B5 (1,10-dithio-18-crown-6), B6 (1,10-dithio-21-crown-7), under mild conditions, were reported. The ligands were characterized by FT-IR, H NMR and GC-MS spectroscopy. The formation of 1:1 ligand complexes with a variety of metal salts...
This study demonstrates the spectral data for two triarylmethane dyes, malachite green (MG) and crystal violet (CV) at room temperature. Effects of micellar environment, and crown ether addition on the spectral behaviour of the dyes were studied using absorption spectroscopic method. The dye-anionic surfactant interactions in micellar media were investigated. The chosen surfactants with differe...
Macrocyclic compounds (crown ethers), specifically 18-crown-6 (18-C-6), benzo-15-crown-5 (B-15-C-5), di-benzo-18-crown-6 (DB-18-C-6) and di-cyclohexano-18-crown-6 (DC-18C-6), are used as extractants as well as synergists with amine-group extractants. Platinum and rhodium belong to platinum-group metals (PGMs) and have very similar ionic radii and similar properties. The separation of PGMs is mo...
the extraction of gadolinium (gd) from perchlorate and nitrate media in 1,2-dichloroethane(c2h4cl2), carbon tetrachloride (ccl4) and chloroform (chcl3) by mixtures of 2-thenoyltrifluoroacetone (htta) and a crown ether benzo-15-crown-5 (b15c5) is investigated.the composition of the extracted species is determined as gd(tta)3.nb15c5 (n=1 in nitratemedium and n=2 in perchlorate medium). the values...
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...
N,N'-bis(bromobenzyl) and N,N'-bis(halopyridinyl) derivatives of diaza-12-crown-4, diaza-15-crown-5 and diaza-18-crown-6 ethers were synthesized in high yields. The Pd-catalyzed macrocyclization reactions of these compounds were carried out using a variety of polyamines and oxadiamines were carried out to give novel macrobicyclic and macrotricyclic compounds of the cryptand type. The dependence...
The coextraction of water with benzo-15-crown-5 (B1SC5), benzo-18-crown-6 (B18C6) and the B18C6-K+ complex into seven low-polar solvents, i.e., carbon tetrachloride (CTC), chloroform (CF), dichloromethane (DCM), 1,2-dichloroethane (1,2-DCE), benzene (BZ), chlorobenzene (CB) and o-dichlorobenzene (o-DCB), has been investigated. The mean hydration number, nH2O, of these solutes in the water-satur...
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...
Based on 15-crown-5 functionalized CdSe/ZnS quantum dots (QDs), we report a novel fluorogenic sensor to probe K+ ions in H2O; recognition of K+ can be achieved via the Förster type of energy transfer between two different color QDs, so that [K+] of the order of 10(-6) M can be promptly detected.
A series of subporphyrin-based fluorescent probes bearing 1-aza-15-crown-5 or 1-aza-18-crown-6 moieties at the meso axial positions were prepared by Pd-catalyzed Buchwald-Hartwig amination reaction corresponding bromosubporphyrins. Both types aza-crown-ether-incorporated subporphyrins in solution and exhibited cation-dependent absorption fluorescence changes. In titration experiments, opposite ...
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