pH-Triggered Assembly of Organometallic Receptors for Lithium Ions
摘要:
The reaction of half-sandwich complexes of ruthenium, rhodium, and iridium with amino-substituted 3-hydroxy-2-pyridone ligands in aqueous solution gives monomeric O,O'-chelate complexes. Upon addition of base, the complexes assemble to form trimeric metallamacrocycles, as evidenced by NMR spectroscopy and single-crystal X-ray analyses. The macrocycles are able to act as highly selective receptors for lithium ions. The binding constants depend on the nature of the half-sandwich complex. the ligand, and the pH. With a commercially available (cymene)Ru complex, a receptor with a Li-divided by binding Constant of K-a = 5.8 (+/-1.0) x 10(4) M-1 and a Li-divided by-Na+ selectivity of 10 000:1 can be obtained. The fact that the assembly process of the receptor is pH-dependent can be used to detect the presence of lithium ions by a pH measurement. Furthermore, it is possible to transduce the binding of Li-divided by into a change of color by means of a chemical reaction with FeCl3. This allows the detection of Li-divided by in the pharmacologically relevant concentration range of 0.5-1.5 mM by the "naked eye".
1H and 13C NMR spectral studies of some Mannich bases. Revised structures for the mono-substituted products from 3-hydroxy-2-pyridone
摘要:
H-1 and C-13 chemical shifts and J(HH) and J(CH) coupling constants are reported for a series of mono-Mannich bases derived from 3-hydroxy-2-pyridone. These compounds should be regarded as the 4-isomers rather than the 6-isomers proposed previously.
THERAPEUTIC HYDROXYPYRIDINONES, HYDROXYPYRIMIDINONES AND HYDROXYPYRIDAZINONES
申请人:Lavoie Edmond J.
公开号:US20150232454A1
公开(公告)日:2015-08-20
The invention provides compounds of formula (I): and salts and prodrugs thereof wherein R4, X1 and X2 have any of the meanings defined in the specification, as well as pharmaceutical compositions comprising the compounds or salts and methods for their use in therapy. The compounds have useful antiviral properties.
Selection experiments with dynamic combinatorial libraries: the importance of the target concentration
作者:Isabelle Saur、Kay Severin
DOI:10.1039/b417824f
日期:——
Experimental data are presented which demonstrate that the target concentration has a strong influence on the outcome of selection experiments with a dynamic mixture of self-assembled receptors.