- Photoactive Cryptands Synthesis of the Sodium Cryptates of Macrobicyclic Ligands Containing Bipyridine and Phenanthroline Groups
-
The NaBr cryptates of five macrobicyclic ligands containing bipyridine (bpy) and phenanthroline (phen) groups, i.e. of 1 2 3 4 and 5, have been prepared. 1, 2, 4 and 5 have been obtained in high yield by condensation of bis(bromomethyl)bipyridine 6 or -phenanthroline 9 with the corresponding macrocyclic diamines in presence of Na2CO3.Direct access to the NaBr complexes of the symmetrical cryptands 1 and 3 was achieved by a one-step macrobicyclisation procedure.The metal-ion complexes of ligands 1-5 have the attractive feature of combining the cation inclusion nature of cryptates with the photoactivity of bipyridine and phenanthroline groups; they may thus be expected to possess a variety of interesting physical and chemical properties.
- Rodriguez-Ubis, Juan-Carlos,Alpha, Beatrice,Plancherel, Dominique,Lehn, Jean-Marie
-
-
Read Online
- 6,6′-Dimethyl-2,2′-bipyridine-4-ester: A pivotal synthon for building tethered bipyridine ligands
-
We describe an efficient and scalable synthesis of 4-carbomethoxy-6,6′-dimethyl-2,2′-bipyridine starting from easily available substituted 2-halopyridines and based on the application of modified Negishi cross-coupling conditions. This compound is a versatile starting material for the synthesis of 4-functionalized 2,2′-bipyridines bearing halide, alcohol, amine, and other functionalities, suitable for conjugation to biological material (2a-c, 3a-g). The utility of this compound in the construction of more complex architectures was further demonstrated by the synthesis of two bifunctional lanthanide chelators; an open chain ligand based on one 2,2′-bipyridine unit and a cryptand based on three 2,2′-bipyridine units [N2(bpy)3COOMe]. In the field of luminophoric biolabels, the photophysical properties of the corresponding Eu(III) cryptate are reported.
- Havas, Fabien,Leygue, Nadine,Danel, Mathieu,Mestre, Béatrice,Galaup, Chantal,Picard, Claude
-
scheme or table
p. 7673 - 7686
(2009/12/06)
-
- Podands, Coronands and Cryptands as New Complex-Ligands in Photoelectron Transfer Reactions. Synthesis and Photophysical Studies
-
Podands, coronands and cryptands containing 2,2'-bipyridine-units were synthesized.These compounds can be used as ligands in Ru(II)-polypyridinecomplexes.This new route principally allows the preparation of tris-heteroleptic complexes using the appropriate cryptands.Ru(II)-polypyridines RuL3(2+) (e.g.Ru(bpy)3(2+)) are interesting as sensitizers in photochemical water cleavage.Compared to Ru(bpy)3(2+), the photoanationrate should be reduced in the Ru(cryp)(2+) complex. - Keywords: Podands, Coronands, Cryptands, Photosensitizer, Photoanation
- Duerr, Heinz,Zengerle, Klaus,Trierweiler, Hans-Peter
-
p. 361 - 368
(2007/10/02)
-
- Reaction of Tosylamide Monosodium Salt with Bis(halomethyl) Compounds: An Easy Entry to Symmetrical N-Tosyl Aza Macrocycles
-
A one-step, general procedure for a variety of N-tosyl aza macrocycles (including aza-crown ethers, pyridino- and bipyridino-aza-crown analogues, and azacyclophanes), by reaction of appropriate bis(halomethyl) precursors with tosylamide monosodium salt (TsNHNa) in N,N-dimethylformamide, is described.In polymethyl-substituted 2,11-diazacyclophane systems, the methyl substituents play an important role in inducing stereospecific ring closures.Thus, coupling of 1,4-bis(chloromethyl)-2,5-dimethylbenzene (15b) with TsNHNa produced only one of the two possible diastereomeric dimers, to which chiral structure 16db was assigned by means of the chiral Eu(dcm)3 shift reagent.This stereochemical assignment was confirmed by a single-crystal X-ray study on 16d.Detosylation of N-tosyl aza macrocycles to the free polyamino macrocycles by reductive (Na-NH3) or hydrolytic (90percent H2SO4) methods, followed by N-methylation (CH2O-HCO2H), was also accomplished in excellent yield.The 1H NMR spectra of 2,11-diazacyclophanes and 2,11-diaza(2,6)pyridinophanes are discussed in terms of conformation and conformational mobility.
- Bottino, Francesco,Grazia, Michele Di,Finocchiaro, Paolo,Fronczek, Frank R.,Mamo, Antonino,Pappalardo, Sebastiano
-
p. 3521 - 3529
(2007/10/02)
-
- A VERSATILE ONE-POT SYNTHESIS OF SYMMETRICAL N-TOSYLAZAMACROCYCLES
-
A variety of title compounds (azacrown ethers, pyridino-azacrown analogues and azacyclophanes) have been synthesized in moderate to good yield by coupling appropriate bis(halomethyl) or bis(tosylate ester) precursors with tosylamide monosodium salt.A revised mechanism is proposed.
- Pappalardo, Sebastiano,Bottino, Francesco,Grazia, Michele Di,Finocchiaro, Paolo,Mamo, Antonino
-
p. 1881 - 1884
(2007/10/02)
-