01734nas a2200241   4500008004100000022001400041245018600055210006900241260010600310300001400416490000700430520077100437653001601208653001301224653001301237653001101250653001201261653001801273100002401291700002301315700002501338856012901363       2006                        eng d  a0040-402000aCyclitol based metal complexing agents. preference for the extraction of lithium by myo-inositol based crown-4-ethers depends on the relative orientation of crown ether oxygen atoms0 aCyclitol based metal complexing agents preference for the extrac  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a4360-43630 v623 a<p>myo-Inositol derived crown-4-ethers in which two of the oxygen atoms in the crown ether moiety have different relative orientations were prepared. Metal picrate binding studies revealed that the crown ether having 1,3-diaxial orientation shows the highest selectivity for binding to lithium although the crown ether having 1,2-diequatorial orientation exhibited the highest binding constant for lithium picrate. These results suggest that relative binding affinity of metal ions to crown ethers can be tuned by varying the relative orientation of crown ether oxygen atoms. The relevance of these results to the previously observed regioselectivity during the O-substitution of myo-inositol orthoesters is discussed. (c) 2606 Elsevier Ltd. All rights reserved.</p>10acrown ether10aCyclitol10aInositol10aligand10alithium10ametal complex1 aDixit, Shailesh, S.1 aShashidhar, M., S.1 aDevaraj, Subramanian  uhttps://library.ncl.res.in/content/cyclitol-based-metal-complexing-agents-preference-extraction-lithium-myo-inositol-based-001712nas a2200229   4500008004100000022001400041245016500055210006900220260010600289300001400395490000700409520079500416653001601211653001301227653001301240653001101253653001801264653001801282100002401300700002701324856013101351       2008                        eng d  a0040-402000aInositol derived crown ethers: effect of auxiliary protecting groups and the relative orientation of crown ether oxygen atoms on their metal ion binding ability0 aInositol derived crown ethers effect of auxiliary protecting gro  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcFEB  a2160-21710 v643 a<p>The binding constants of crown ethers prepared from tetra-O-substituted myo- and scyllo-inositol derivatives and 2-O-substituted myo- and scyllo-inositol-1,3,5-orthoformates, with metal picrates show that the O-substituents and the relative orientation of the crown ether oxygen atoms contribute significantly to the binding of crown ethers with metal ions. In particular, the binding efficiency of myo-inositol derived crown ethers to silver and potassium ions could be enhanced by introducing benzyl ethers in the inositol ring. Hence binding efficacy and selectivity of metal ions to inositol derived crown ethers can be tuned by varying substituents on the myo-inositol ring and/or the relative orientation of crown ether oxygen atoms. (C) 2007 Elsevier Ltd. All rights reserved.</p>10acrown ether10aCyclitol10aInositol10aligand10ametal complex10asupramolecule1 aDixit, Shailesh, S.1 aShashidhar, Mysore, S.  uhttps://library.ncl.res.in/content/inositol-derived-crown-ethers-effect-auxiliary-protecting-groups-and-relative-orientation-0