Synthesis of novel lanthanide acylpyrazolonato ligands with long aliphatic chains and immobilization of the Tb complex on the surface of silica pre-modified via hydrophobic interactions

Five new complexes Ln(QC17)3(H2O)(Solv) (Ln = Y, Solv = H2O, Ln = Tb, Dy, Sm or Eu, Solv = EtOH) were synthesized with the acylpyrazolonato ligand QC17 bearing a long aliphatic C17H35 chain in the acyl moiety, and the crystal structure of Y(QC17)3(H2O)2 shows the three aliphatic chains from the coordinated ligands positioned in the same direction, affording plane layers built by Y(QC17)3(H2O)2 molecules connected through H-bonding interactions. The layers are stitched to each other like in “hook & loop” tapes. Luminescence of complexes was determined and the complex Tb(QC17)3(H2O)(EtOH) was immobilized on the surface of silica preprocessed using a C17H35CONH(CH2)3Si(OEt)3 reagent via hydrophobic interactions of long aliphatic chains. Luminescent properties and micromorphology of the obtained hybrid particles and hybrid films were investigated. Intensive green emission of the complex retains after grafting onto the silica surface. Inclusion of the complex on the surface of silica materials occurs as separate molecules, after the disruption of the H-bonding network present in the crystalline phase of the pure terbium sample

Lewis Acid Triggered Vinylcyclopropane–Cyclopentene Rearrangement

We report a mild Lewis acid induced isomerization of donor–acceptor cyclopropanes, containing an alkenyl moiety and diverse electron-withdrawing group(s) at the adjacent positions, into substituted cyclopentenes. We have found that 1,1,2-trisubstituted cyclopent-3-enes were exclusively obtained in yield of 51–99% when cyclopropanes with a 2-substituted alkenyl group as a donor underwent isomerization. For cyclopropanes bearing a trisubstituted alkenyl group either the corresponding cyclopent-3-enes or isomeric cyclopent-2-enes having two acceptor groups at the C(1) atom were formed, with the reaction selectivity being determined by the applied Lewis acid. We have shown that the reactivity of the donor–acceptor cyclopropane increases with the increase of the electron-donating character of (hetero)­aromatic group attached to the alkenyl moiety. The synthetic utility of the developed methodology was also demonstrated through the synthesis of polysubstituted cyclopentane and piperidine derivatives