[2]Catenanes and inclusion complexes derived from self-assembled rectangular PdII and PtII metallocycles

Abstract

New inclusion complexes and [2]catenanes were self-assembled from a fluorescent diazapyrenium based ligand, a Pd II or Pt II complex, and cyclic or acyclic electron rich aromatic guests in aqueous and organic media. The molecular rectangles display a π-deficient cavity suitable to incorporate π-donor aromatic systems. The inclusion complexes between the metallocycles and phenylenic (2a,b) and naphthalenic (3a,b-5a,b) derivatives were studied by NMR, UV-vis and fluorescence spectroscopy. The crystal structure of (3b) ⊂ 1a·6PF 6 confirmed the insertion of the guest into the cavity of the metallocycle. Following the same self-assembly strategy, the use of polyethers 6,7 as π-donors resulted in the self-assembly of the [2]catenanes 1a(6,7)·6PF 6 . Single-crystal X-ray analysis of 1a(7)·6PF 6 revealed the [2]catenane structure being stabilized by π-stacking and [C-H⋯O] interactions.

Subcellular Duplex DNA and G‐Quadruplex Interaction Profiling of a Hexagonal PtII Metallacycle

“…[26] Inspired by recent works of Wasielewski and Stoddart on cyclophanes bearing isolated phenyl-extended viologen moieties, [27,28] we argued that the ditopic pyridyl ligand L1 (Figure 1a)w ould confer an adequate emission profile to the final supramolecule and overcome quenching effects typical of SCCs. [29][30][31] Theh ighly emissive biphenylextended viologen moiety ( Figure 1, in turquoise) would maintain al igand-centered emission profile when incorporated in the corresponding dinuclear Pt II -metallacycle 1 due to the non-direct connectivity to the metal centers.F urthermore,the dimensions (ca. 200 2 )and the octacationic nature of 1 are quite similar to those of our previously reported DNA/quadruplex binders, [25] af act that we envisaged would translate as well into ac omparable DNA-binding profile.…”

Metallacyclic assembly of interlocked superstructures

“…The construction of different hybrid catenanes based on polyether donors[103][104][105][106][107][108][109][110].…”

Neutral discrete metal–organic cyclic architectures: Opportunities for structural features and properties in confined spaces

“…topological structures and interesting functions [209][210][211][212][213][214][215][216][217][218][219][220]191,[221][222][223][224][225][226][227][228][229]. The generation of tetranuclear metallacycles with fascinating structural and spectroscopic properties, such as luminescence, is of particular interest because of the limited number of luminescent hosts that are available.…”