Cruciform‐Silica Hybrid Materials

Silica scaffolding : By employing functionalized mesoporous SBA‐15 silica, novel fluorescent cruciform‐silica hybrid materials are generated which preserve the desirable solution properties of cruciforms in the solid state for potential use in sensory schemes.

     

Water Soluble Cruciforms: Effect of Surfactants on Fluorescence

Brighten up! Adding surfactants to aqueous solutions of three different water‐soluble cruciforms (XF) improves their fluorescence quantum yields. Additionally, changes are observed in the emission wavelength of the XF around the critical micelle concentration (cmc) of the surfactant.

     

Controlling polymer properties through dynamic metal-ligand interactions: supramolecular cruciforms made easy

A straightforward methodology towards the supramolecular synthesis of novel organometallic polymers with attractive optical properties is presented. By coordinating bifunctional fluorescent cruciform molecules through ditopic metalated pincer complexes (Pd or Pt), we have synthesized a new class of well-defined coordination polymers that have controllable and tunable physical and photophysical properties. The formation of these new materials by employing metal coordination was monitored by (1)H NMR spectroscopy, the association strength of the metal-ligand interaction was measured by isothermal titration calorimetry, the solution polymeric properties were evaluated by viscometry, and the optical properties were measured and observed by fluorescence spectroscopy. The fast and quantitative synthesis of a wide range of prefabricated monomeric cruciform and metalated-pincer-complex components will allow for the rapid generation, growth, and optimization of this new class of functional polymers, which have potential electronic and optical applications.     

The Photophysics of Pyridine‐Derivatized ortho‐, meta‐, and para‐Dibutylamino Cruciforms

The photophysical properties of a series of para‐substituted donor–acceptor cruciform fluorophores ( p 1 – 4 ) were investigated and compared with their meta and ortho isomers ( m 1 – 4 and o 1 – 4 ). The structural variations were found to have a significant effect on the solvatochromism, fluorescence quantum yields (Φ_fl), fluorescence lifetimes (τ_fl), and response upon addition of trifluoroacetic acid. The observed spectral shifts in absorption and emission caused by protonation of the cruciforms make them promising candidates as chemosensors. Additional computational studies provided more insight into the electronic structure of the systems.