Andrei Andrievsky

Combinatorial synthesis of modular chiral cyclophanes

Abstract A new chiral cyclophane incorporating the 4,4′-bipyridinium dication and a dipeptide subunit forms complexes with amino acid derivatives and allows for the preparation of combinatorial libraries of hydrogen bonding, π-acidic chiral selectors.

Sapphyrin–lasalocid conjugate: a novel carrier for aromatic amino acid transport

Sapphyrin, when connected covalently to lasalocid, acts as a selective carrier for the through-model-membrane transport of zwitterionic aromatic amino acids.

Enhanced DNA photocleavage and binding properties of sapphyrin-polyamine conjugates

Abstract The synthesis of several water-soluble sapphyrin derivatives is described. Of these, the sapphyrins 2–4 , bearing appended polyamines, exhibit enhanced DNA photocleavage and binding over sapphyrin 1 as determined from pBR322 plasmid cleavage experiments and an ethidium bromide displacement fluorescence assay.

Oligosapphyrins: receptors for the recognition and transport of nucleotide di- and tri-phosphates

Covalently connected oligosapphyrins, in particular two trimers (linear and branched) and a tetramer, the syntheses of which are detailed, have been found to be effective receptors for the binding and through-model-membrane transport of nucleotide mono-, di- and tri-phosphates.

Energy Transfer in a Supramolecular Complex Assembled via Sapphyrin Dimer-mediated Dicarboxylate Anion Chelation

The synthesis of a new terephthalate-strapped porphyrin is described. This porphyrin, prepared in the form of the free base and corresponding zinc(II) complex, was designed to act as the photo-donor portion of a novel, non-covalent artificial light-harvesting complex, the other, acceptor component of which is comprised of a covalently linked sapphyrin dimer. UV-vis and 1H NMR spectroscopic analyses were used to establish that strong complexes are formed between the porphyrin terephthalate and sapphyrin dimer components (affinity constants on the order of 105 M−1 in dichloromethane). In these complexes the dicarboxylate portion of the strapped porphyrin is sandwiched between two sapphyrins of an individual dimer. Steady state fluorescence studies of the resulting ensembles support the conclusion that, upon photoexcitation of the porphyrin subunit, energy transfer from the porphyrin to the sapphyrin dimer occurs efficiently. This intra-ensemble, anion-chelation-based energy transfer can be inhibited by the addition of fluoride anion.