Extraction arenes

An extensive survey has been carried out by McKervey and coworkers [7], who prepared the carbo-alkoxymethyl ethers of p-tert-h x y calix[4]arene, p-/< r/-butyl calix[6]arene, p-tert-bu y calix[8]arene, ca-lix[4]arene, calix[6Jarene, and calix[8]arene, and measured their abilities to extract cations from the aqueous phase into the nonaqueous phase. They concluded the following general aspects for the phase-transfer experiments (1) the calix[4]arene compounds show the greatest selectivity for Na (2) phase-transfer of Li is inefficient with all of the compounds (3) the calix[6]arene compounds show less affinity for Na than for K, with plateau selectivity for Rb" and Cs (4) the calix[8]ar-ene compounds are the least efficient of the cyclic oligomers, showing low levels of transport and low discrimination for all five cations (5) the calix[6]arene... 

Calestani et al. [8] prepared dietylamide of the tetra-carboxymethyl ether of p-tert-h W.y calix[4]arene and reported alkali metal picrate extraction constants of 1.9... 

Harrowfield et al. [37-39] have described the structures of several dimethyl sulfoxide adducts of homo bimetallic complexes of rare earth metal cations with p-/e rt-butyl calix[8]arene and i /i-ferrocene derivatives of bridged calix[4]arenes. Ludwing et al. [40] described the solvent extraction behavior of three calixarene-type cyclophanes toward trivalent lanthanides La (Ln = La, Nd, Eu, Er, and Yb). By using p-tert-huty ca-lix[6Jarene hexacarboxylic acid, the lanthanides were extracted from the aqueous phase at pH 2-3.5. The ex-tractability is Nb, Eu > La > Er > Yb. 

Yosida et al. [41] found that p-t< rr-butylcalix[6]ar-ene can extract Cu from the alkaline-ammonia solution to the organic solvent. Nagasaki and Shinkai [42] described the synthesis of carboxyl, derivatives of calix-[n]arenes ( = 4 and 6) and their selective extraction capacity of transition metal cations from aqueous phase to the organic phase. Gutsche and Nam [43] have synthesized various substituted calix[n]arenes and examined the complexes of the p-bromo benzene sulfonate of p-(2-aminoethyl)calix[4]arene with Ni, Cu , Co-, and Fe. ... 

Recently, Deligoz and Yilmaz [51] prepared three polymeric calix[4]arenes, which were synthesized by reacting chloromethylated polystyrene with 25,26,27-tribenzoyloxy-28-hydroxy calix[4]arene (2a, 3a) and po-lyacryloyl chloride with 25,26,27,28-tetraacetoxy ca-lix[4]arene (4a). After alkaline hydrolysis of the polymers, they were utilized for selective extraction of transition metal cations from aqueous phase to organic phase. 

To support a polystyrene onto the upper rim of ca-lix[4]arene (phenolic-O- of calix[4]arene) and 25,26,27-tribenzoyloxy-28-hydroxy, calix[4]arene was treated with chloromethylated polystyrene in the presence of K2CO3 (Scheme 7). Polymeric calix[4]arene (3a) thus obtained was hydrolyzed in the benzoyl groups prior to use for the extraction process. 

Selective extraction experiments were then performed to see transference of some transition elements (Cu ", Ni ", Co ", and Fe " ) from the aqueous phase to the organic phase by the synthesized polymeric calixarenes. Phase-transfer studies in water-chloroform confirmed that polymer 2b and 3b were Fe ion-selective as was its monomer (1). Extraction of Fe " cation with 2b and 3b was observed to be maximum at pH 5.4. Only trace amounts of other metal cations such as Cu, Ni ", and Co " were transferred from the aqueous to the organic phase (Table 3). Furthermore, the extracted quantities of these cations remained unaffected with increasing pH. The effect of pH on the extraction of 3b was lower and 56% extraction was accomplished even at pH 2.2. The extraction experiments were also performed with calix[4]arene (1) the ratio was 8.4% at pH 2.2. The polymeric calix[4]arenes were selective to extract Fe " from an aqueous solution, which contained Cu +, Ni, Co ", and Fe " cations, and it was observed that the... 

Extraction of Fe with calix[4jarene, which was 7%, has increased to 82% when the polymeric calix[4]arene... 

Deligoz and Yilmaz [52] reported that the selective liquid-liquid extraction of various alkali and transition metal cations from the aqueous phase to the organic phase as carried out by using p-tert-h iy calix[4]arene (1), p-tert-b x. y calix[6]arene (2), tetra-ethyl-p-tm-butylcalix[4]arene-tetra-acetate (3), tetra-methyl-p-/< /-/-butyl calix[4]arene-tetraketone (4), calix[n]arenes ( = 4 and 6) bearing oxime groups on the lower rim (5 and 6) and a polymeric calix(4]arene (8). It was found that compounds 5 and 6 showed selectivity towards Ag, Hg, Hg, Cu, and Cr and the order of the ex-tractability was Hg > Hg > Ag > Cu > Cr. The polymeric calix[4]arene (8) was selective for Ag, Hg, and Hg , unlike its monomeric analog. 

It was observed that while the ester (3) and ketone (4) derivatives of p-/erf-butyl calix[4]arene extracted negligibly small amounts of Cu " and Cr " ions, its oxime derivative efficiently extracted these ions. Furthermore, 5 was found to be more effective than 6 in extracting Cr ion. 

To investigate whether these results were caused by the oligomer (7) or calix[4]arene itself, experiments were performed with calix[4]arene, before it was reacted with 7. Observations showed that when extraction was performed with unreacted calix[4]arene, the transfer of Ag", Hg", and Hg " ions was very close to unity. The compound (8) contains benzoyl groups. To understand the effect of this group on the extraction process, the... 

Hydroxylamine, IV-benzoyl-lV-phenyl-in gravimetry, 1, 532 liquid-liquid extraction, 1, 544 Hydroxylamine, A -cinnamoyl-A -phenyl-liquid-liquid extraction, 1,544 Hydroxylamine, Ar,A -di-(-butyl-metal complexes, 2, 798 Hydroxylamine, Ay/V-diethyl-metal complexes, 2,798 Hydroxylamine, AAmethyl-metal complexes, 2,798 Hydroxylamine, A -2-naphthol-A -nitroso-ammonium salt — see Ncocupferron Hydroxylamine, A -nilrosophenyl-ammonium salt — see Cupferron Hydroxylamine ligands, 2, 101 Hydroxylamine oxido reductase, 6, 727 Hydroxylases molybdenum, 6,658,662 Hydroxylation arenes... 

As neutral carriers for the chemical modification, 16-crown-5 and calix[4]arene derivatives possessing a triethoxysilyl group (7) and (8) were designed for Na sensors. Triethoxysilylethyl-16-crown-5(7) was then mixed with a silicone-rubber precursor for the membrane fabrication accompanying covalent bonding of the neutral carrier. Comparison of IR spectra before and after extraction of the nonbonded neutral carrier... 

The silver(I) complexes with the tetrakis(methylthio)tetrathiafulvalene ligand have been reported, the nitrate salt presents a 3D structure with an unprecedented 4.16-net porous inorganic layer of silver nitrate,1160 the triflate salt presents a two interwoven polymeric chain structure.1161 The latter behaves as a semiconductor when doped with iodine. With a similar ligand, 2,5-bis-(5,5,-bis(methylthio)-l,3,-dithiol-2 -ylidene)-l,3,4,6-tetrathiapentalene, a 3D supramolecular network is constructed via coordination bonds and S"-S contacts. The iodine-doped compound is highly conductive.1162 (Methylthio)methyl-substituted calix[4]arenes have been used as silver-selective chemically modified field effect transistors and as potential extractants for Ag1.1163,1164... 

It has been shown that upper-rim substitution of some dithiocarbamoyl-derivatized calix[4]arenes affects selectivity of Ptr extraction.327,329 Some selectivity over Pb, Hgn, and Ptn has been achieved by the introduction of 2-pyridyl-A-oxide groups on the lower rim, but Sn11, Ag1, Pd11, and Au111 were still extracted to a greater extent.32... 

Yordanov, A. T. Mague, J. T. Roundhill, D. M. Solvent extraction of divalent palladium and platinum from aqueous solutions of their chloro complexes using an N,N- dimethyldithiocarbamoylethoxy substituted calix 4 arene. Inorg. Chim. Acta 1995, 240, 441 146. 

Ohto, K. Higuchi, H. Inoue, K. Solvent extraction of silver with pyridino calix-4-arenes. Solvent Extr. Res. Dev-Jpn. 2001, 8, 37 16. 

Ohto, K. Yamaga, H. Murakami, E. Inoue, K. Specific extraction behavior of amide derivative of calix-4-arene for silver (I) and gold (III) ions from highly acidic chloride media. Talanta 1997, 44, 1123-1130. 

Regnouf-de-Vains, J. B. Dalbavie, J. O. Lamartine, R. Fenet, B. Quantitative solvent extraction from neutral aqueous nitrate media of silver(I) against lead(II) with a new calix-4-arene-based bipyridine podand. Tetrahedron Lett. 2001, 42, 2681-2684. 

Memon, S. Yilmaz, M. Liquid-liquid extraction of alkali and transition metal cations by two biscalix[4]arenes. Sep. Sci. Technol. 2000, 35, 457-467. 

Further experiments focused therefore on [RuCl(en)(r 6-tha)]+ (12) and [RuCl(rj6-p-cym)(en)]+ (22), which represent the two different classes, and their conformational distortion of short oligonucleotide duplexes. Chemical probes demonstrated that the induced distortion extended over at least seven base pairs for [RuCl(rj6-p-cym)(en)]+ (22), whereas the distortion was less extensive for [RuCl(en)(rj6-tha)]+ (12). Isothermal titration calorimetry also showed that the thermodynamic destabilization of the duplex was more pronounced for [RuCl(r 6-p-cym)(en)]+ (22) (89). DNA polymerization was markedly more strongly inhibited by the monofunctional Ru(II) adducts than by monofunctional Pt(II) compounds. The lack of recognition of the DNA monofunctional adducts by HMGB1, an interaction that shields cisplatin-DNA adducts from repair, points to a different mechanism of antitumor activity for the ruthenium-arenes. DNA repair activity by a repair-proficient HeLa cell-free extract (CFE) showed a considerably lower level of damage-induced DNA repair synthesis (about six times) for [RuCl(en)(rj6-tha)] + compared to cisplatin. This enhanced persistence of the adduct is consistent with the higher cytotoxicity of this compound (89). 

The dichlororuthenium arene dimers are conveniently prepared by refluxing ethanolic ruthenium trichloride in the appropriate cyclohexadiene [19]. The di-chloro(pentamethylcyclopentadienyl) rhodium dimer is prepared by refluxing Dewar benzene and rhodium trichloride, whilst the dichloro(pentamethylcyclo-pentadienyl)iridium dimer is prepared by reaction of the cyclopentadiene with iridium trichloride [20]. Alternatively, the complexes can be purchased from most precious-metal suppliers. It should be noted that these ruthenium, rhodium and iridium arenes are all fine, dusty, solids and are potential respiratory sensitizers. Hence, the materials should be handled with great care, especially when weighing or charging operations are being carried out. Appropriate protective clothing and air extraction facilities should be used at all times. 

Dissolve the mixture in ether. Ether is insoluble in the water solutions you will extract into. Ether happens to dissolve all four compounds. Aren t you lucky You bet It takes lots of hard work to come up with the typical student example. ... 

The (dibromomethy l)arene (1 mmol) is heated under reflux with NaOAc (0.35 g), CaC03 (0.215 g) and TBA-Br (75 mg, 0.23 mmol) in H20 (5 ml). The mixture is filtered and the filtrate is made neutral by the addition of dilute HC1. The aqueous solution is extracted with CH2C12 (3 x 15 ml) and the dried (MgS04) extracts are evaporated to yield the aldehyde. 

TosN, (0.37 g, 2 mmol), the arylhydrazine (2 mmol), and TEA-Br (0.1 g, 0.5 mmol) in xylene (10 ml) are added to aqueous NaOH (50%, 10 ml) and the mixture is refluxed until the azide has been fully consumed (2-10 h). The organic phase is separated and the aqueous phase is extracted with PhH (3 x 10 ml). The combined organic solutions are dried (MgS04) and evaporated to yield the arene [e.g. PhH 40% (6 h) pyridine 98% (6 h) from 2-hydrazino derivative pyridazine 79% (8 h) from 3-hydrazino derivative)]. 

Aqueous NaOH (50%, 30 ml) is added dropwise over 15 min to the arene (50 mmol) and CTMA-C1 (1.33 g, 5 mmol) in CHC1, (12 ml) at 50°C.The mixture is stirred fora further 2.5 h and then diluted with H20 (100 ml) and acidified to pH 2 with H2S04 (10%). The aqueous mixture is extracted with EtOAc (3 x 50 ml) and the dried (Na2S04) extracts are evaporated to give the insertion products. 

Table 12.5 Comparison of the Extraction Selectivity of Two p-terr-butylcalix(6)arene, Uranophiles, Bearing 6 Carboxylates 1(6) or 6 Hydroxamates 2(6) Groups on the Lower Rim...

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