共查询到7条相似文献,搜索用时 4 毫秒
1.
Reed M. Izatt Gypzy C. Lindh Jan F. Biernat Maria Bochenska Ronald L. Bruening Jerald S. Bradshaw James J. Christensen 《Journal of inclusion phenomena and macrocyclic chemistry》1989,7(5):487-499
The transport of alkali metal cations by several macrocycles possessing two sulfonamide groups as a part of an 18-, 20-, or 21-membered macroring has been studied. Some of these compounds were found to be more effective transport agents than the proton-ionizable pyridone- and triazole-containing crown ethers reported previously. The factors affecting transport, such as ring size, source and receiving phase pH, and the nature of the groups attached to the sulfonamide nitrogen atoms were examined. Also, extraction experiments by some of the ligands were performed. The behavior of sulfonamide type crowns in single and competitive transport of the alkali metal cations is explained. The mechanism of transport appears to be complex. Transport of one or two cations per molecule of the disulfonamide carriers occurs. Complexation of these cations appears to occur both within and outside the macrocycle cavity. Our results also suggest that kinetic factors may play a significant role in transport rates and selectivities.Deceased: September 5, 1987. 相似文献
2.
Jerald S. Bradshaw Yohji Nakatsuji Peter Huszthy Bruce E. Wilson N. Kent Dalley Reed M. Izatt 《Journal of heterocyclic chemistry》1986,23(2):353-360
New proton-ionizable macrocyclic polyether ligands containing the 4-pyridone subcyclic unit have been prepared by reacting 4-THP blocked-2,6-pyridinedimethanol with various oligoethylene glycol ditosylates. The 18-crown-6 ligand containing the 4-pyridone subcyclic unit, 4 , forms stable complexes with alkali metal and organic ammonium cations. The crystal structure of 4 proves the 4-pyridone structural unit. The crystal structure of the potassium thiocyanate complex of 4 is also reported and shows the complex to contain the 4-hydroxypyridine unit. 相似文献
3.
Jerald S. Bradshaw Hiroyuki Koyama N. Kent Dalley Reed M. Izatt Jan F. Biernat Maria Bochenska 《Journal of heterocyclic chemistry》1987,24(4):1077-1083
Eight new macrocylic ligands each containing two sulfonamide groups have been prepared. Six of these compounds have both the sulfur and nitrogen atoms of the sulfonamide units substituted with aromatic rings. The nitrogen atoms of the other two compounds have alkyl ring connections. X-ray crystal structure data were obtained for new macrocyclic compounds of 20 and 23 ring members. Each crystal structure showed two molecules in the asymmetric unit. Molecule A of 5 and both molecules of 7 exist in a compact conformation suggesting that they could wrap around a metal ion during complexation. Some of these compounds will be used as cation carriers in a bulk liquid membrane system. 相似文献
4.
Reed M. Izatt Gypzy C. Lindh Ronald L. Bruening Peter Huszthy John D. Lamb Jerald S. Bradshaw James J. Christensen 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(6):739-745
The macrocycle-mediated fluxes of several alkali metal cations have been determined in a H2O-CH2Cl2-H2O liquid membrane system. Water-insoluble proton-ionizable macrocycles of the pyridono type were used. The proton-ionizable feature allows the coupling of cation transport to reverse H+ transport. This feature offers promise for the effective separation and/or concentration of alkali metal ions with the metal transport being driven by a pH gradient. A counter anion in the source phase is not co-transported. The desired separation of a particular metal ion involves its selective complexation with the macrocycle, subsequent extraction from the aqueous phase to the organic phase, and exchange for H+ at the organic phase-receiving phase interface. Factors affecting transport which were studied include ring size, source phase pH, and receiving phase pH. Lithium was transported at a rate higher than that of the other alkali metals in both single and competitive systems using a 15-crown-5 pyridono carrier. 相似文献
5.
Jerald S. Bradshaw John M. Guynn Steven G. Wood Bruce E. Wilson N. Kent Dalley Reed M. Izatt 《Journal of heterocyclic chemistry》1987,24(2):415-419
Four new 14-crown-4 macrocyclic ligands containing either a pyridine or a 4-pyridone subcyclic unit have been prepared. Two of the 4-pyridono-crowns contained lipophilic hydrocarbon substituents. The starting octyl- and benzyl-substituted 4-oxa-1,7-heptanediols were prepared from the 2-octyl- or 2-benzyl-1,3-propane-diol. When the two substituted 4-oxa-1,7-heptanediols were treated with tosyl chloride, both the expected 2-substituted-4-oxaheptane-1,7-ditosylates and the ditosylate of the dimeric diol were isolated. X-ray structure determinations were carried out on two of the new 14-crown-4 compounds. 相似文献
6.
Jerald S. Bradshaw Peter Huszthy Hiroyuki Koyama Steven G. Wood Scott A. Strobel Richard B. Davidson Reed M. Izatt N. Kent Dalley John D. Lamb James J. Christensen 《Journal of heterocyclic chemistry》1986,23(6):1837-1843
Three new proton-ionizable macrocyclic polyether ligands containing the 4-pyridone subcyclic group have been prepared. Two of these ligands contain lipophilic n-octyl substituents, the other ligand contains a phenyl substituent. The 15-crown-5 ligand containing both a 4-pyridone subcyclic unit and an n-octyl substituent selectively transported lithium cations in a water-methylene chloride-water bulk liquid membrane system. Five crown compounds containing the 4-pyridone subcyclic unit were converted to the 4-thiopyridono-crown compounds when treated with Lawesson's Reagent. The crystal structure of 4-thiopyridono-18-crown-6 shows a carbon-sulfur double bond and a molecule of water hydrogen bonded inside the macrocycle cavity. 相似文献
7.
Reed M. Izatt Gypzy C. Lindh Peter Huszthy Glen A. Clark R. L. Bruening Jerald S. Bradshaw James J. Christensen 《Journal of inclusion phenomena and macrocyclic chemistry》1989,7(5):501-509
The macrocycle-mediated fluxes of alkali, alkaline earth, and several transition metal cations have been determined and compared in a H2O-CH2Cl2-H2O liquid membrane system using four water-insoluble macrocycles containing a dialkylhydrogenphosphate moiety. Transport of alkali metal cations by these ligands was greatest from a source phase pH = 12 or above into an acid receiving phase (pH = 1.5). Very low fluxes were observed for the transport of the alkaline earth cations and all transition metal ions studied except Ag+ and Pb2+ which were transported reasonably well by these new macrocycles.Deceased: September 5, 1987. 相似文献