Jarosław Grolik

Dibenzotetraaza[14]annulene–adenine conjugate recognizes complementary poly dT among ss-DNA/ss-RNA sequences

Among three novel DBTAA derivatives only the DBTAA-propyl-adenine conjugate showed recognition of the consecutive oligo dT sequence by increased affinity and specific induced chirooptical response in comparison to other single stranded RNA and DNA; whereby of particular importance is the up until now unique efficient differentiation between dT and rU. At variance, its close analogue DBTAA-hexyl-adenine did not reveal any selectivity between ss-DNA/RNA pointing out the important role of steric factors (linker length); moreover non-selectivity of the reference compound (, lacking adenine) stressed the importance of adenine interactions in the selectivity.

Pyrrolo[2,3-b]quinoxaline with 2-(2-aminoethyl)pyridine chain highly selective fluorescent receptor for Zn2+ exhibiting a dual fluorescence and AIEE in crystalline state

This article describes the synthesis of a selective dual emissive intramolecular charge transfer (ICT) receptor for zinc ion in acetonitrile, exhibiting aggregation induced emission enhancement (AIEE) in the solid state due to the formation of inter- or intra-molecular hydrogen bonds and aromatic donor–acceptor interaction with H- or J-aggregation.

Molecular recognition of AT-DNA sequences by the induced CD pattern of dibenzotetraaza(14)annulene (DBTAA)-adenine derivatives

Summary An investigation of the interactions of two novel and several known DBTAA–adenine conjugates with double-stranded DNA and RNA has revealed the DNA/RNA groove as the dominant binding site, which is in contrast to the majority of previously studied DBTAA analogues (DNA/RNA intercalators). Only DBTAA–propyladenine conjugates revealed the molecular recognition of AT-DNA by an ICD band pattern > 300 nm, whereas significant ICD bands did not appear for other ds-DNA/RNA. A structure–activity relation for the studied series of compounds showed that the essential structural features for the ICD recognition are a) the presence of DNA-binding appendages (adenine side chain and positively charged side chain) on both DBTAA side chains, and b) the presence of a short propyl linker, which does not support intramolecular aromatic stacking between DBTAA and adenine. The observed AT-DNA-ICD pattern differs from previously reported ss-DNA (poly dT) ICD recognition by a strong negative ICD band at 350 nm, which allows for the dynamic differentiation between ss-DNA (poly dT) and coupled ds-AT-DNA.

π–π-Induced aggregation and single-crystal fluorescence anisotropy of 5,6,10b-tri­aza­acephenanthrylene

The influence of π–π overlap in centrosymmetric dimers on the aggregation type, single-crystal absorption and fluorescence anisotropy of the new heterocyclic system 5,6,10b-triazaacephenanthrylene is presented.