RESUMO
The mechanism and thermodynamic functions of the self-assembly of a family of covalently linked oligomeric naphthalenediimides (NDIs) were investigated through variable-temperature NMR and CD studies. The NDIs were shown to self-assemble into helical supramolecular nanotubes via an isodesmic polymerisation mechanism, and regardless of the oligomer length a surprising entropy-enthalpy compensation was observed.
Assuntos
Imidas/química , Nanotubos/química , Naftalenos/química , Termodinâmica , Aminoácidos/química , Imidas/síntese química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Modelos Moleculares , Estrutura Molecular , Naftalenos/síntese químicaRESUMO
A series of Pd(en)X2 salts were used as catalysts for the conversion of aldoximes into nitriles and amides. Highlights of this protocol include the use of inexpensive polar solvents, including water, and moderate reaction temperatures. A high degree of selectivity in the reaction outcome was observed when using aliphatic vs. aromatic/conjugated aldoximes.
RESUMO
Naphthalenemonoimides and N-desymmetrized naphthalenediimides were synthesized using a stepwise microwave-assisted protocol. The steric and electronic properties of aliphatic amines determined the outcome of the reactions, while in the amino acid series their ability to solubilize the naphthalene dianhydride starting material was crucial. Molecular modeling was used to rationalize the observed selectivity.