6533b829fe1ef96bd128a607
RESEARCH PRODUCT
Equipping metallo-supramolecular macrocycles with functional groups: Assemblies of pyridine-substituted urea ligands
Ralf W. TroffRalf W. TroffRainer HovorkaKari RissanenArne LützenMartin NiegerMario CetinaTorsten WeilandtChristoph A. SchalleyDieter Lentzsubject
010405 organic chemistryHydrogen bondChemistryStereochemistrySupramolecular chemistryurea ligands; metallo-supramolecular macrocycles; X-ray structure; hydrogen-bonding010402 general chemistryMass spectrometry01 natural sciencesFourier transform ion cyclotron resonance0104 chemical sciencesInorganic ChemistrySubstituted ureaCrystallographychemistry.chemical_compoundPyridineUreaTwo-dimensional nuclear magnetic resonance spectroscopyta116description
A series of di-(m-pyridyl)-urea ligands were prepared and characterized with respect to their conformations by NOESY experiments and crystallography. Methyl substitution in different positions of the pyridine rings provides control over the position of the pyridine N atoms relative to the urea carbonyl group. The ligands were used to self-assemble metallo-supramolecular M(2)L(2) and M(3)L(3) macrocycles which are generated in a finely balanced equilibrium in DMSO and DMF according to DOSY NMR experiments and ESI FTICR mass spectrometry. Again, crystallography was used to characterize the assemblies. Methyl substitution in positions next to the pyridine nitrogen prevents coordination, while the other ligands form small metallo-supramolecular macrocycles. The incorporated urea carbonyl groups provide hydrogen bonding sites which converge towards the center of the assemblies.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-05-31 | Dalton Transactions |