Blue Emitting Star-Shaped and Octasilsesquioxane-Based Polyanions Bearing Boron Clusters. Photophysical and Thermal Properties

Abstract

High boron content systems were prepared by the peripheral functionalisation of 1,3,5-triphenylbenzene (TPB) and octavinylsilsesquioxane (OVS) with two different anionic boron clusters: closo-dodecaborate (B12) and cobaltabisdicarbollide (COSAN). TPB was successfully decorated with three cluster units by an oxonium ring-opening reaction, while OVS was bonded to eight clusters by catalysed metathesis cross-coupling. The resulting compounds were spectroscopically characterised, and their solution-state photophysical properties analysed. For TPB, the presence of COSAN dramatically quenches the fluorescence emission (λem = 369 nm; ΦF = 0.8%), while B12-substituted TPB shows an appreciable emission efficiency (λem = 394 nm; ΦF = 12.8%). For octasilsesquioxanes, the presence of either COSAN or B12 seems to be responsible for ∼80 nm bathochromic shift with respect to the core emission, but both cases show low emission fluorescence (ΦF = 1.4–1.8%). In addition, a remarkable improvement of the thermal stability of OVS was observed after its functionalisation with these boron clusters.

Radiolabeled Cobaltabis(dicarbollide) Anion–Graphene Oxide Nanocomposites for In Vivo Bioimaging and Boron Delivery

“…33,34,35,36,37 Because of its unique properties, COSAN is able to cross the lipid bilayer membrane of cells and accumulate in different types of living cells, 38 which is confirmed by Raman 39 and fluorescence techniques. 40,41,42 Due to their potential applications, from materials science to biomedicine, COSAN derivatives have been covalently linked to different types of macromolecules, such as dendrimers, 43,44 octasilsesquioxanes 30,45 porphyrins and phthalocyanines. 46,47,48,49 Moreover, they have been grafted to the surface of polymeric nanoparticles, 50 gold nanoparticles, 51 TiO2, 52 single-wall carbon nanotubes (SWCNTs) 53 and graphene oxide, 54 giving rise to materials with enhanced solubility, 55 dispersibility, thermal stability, electrochemical features, cellular uptake and intracellular boron release.…”

Tuning the architectures and luminescence properties of Cu(i) compounds of phenyl and carboranyl pyrazoles: the impact of 2D versus 3D aromatic moieties in the ligand backbone

“…Some of these systems show moderate to good fluorescence emission efficiency in solution and solid state, giving rise to fluorescent materials in both states. [86][87][88][89][90][91] Herein we report the synthesis of three new pyrazolylcarborane derivatives and their Cu(I) compounds. We also report a new Cu(I) derivative of a commercially available N-substituted phenyl pyrazole ligand (L1) that was taken for comparison between 2D and 3D aromatic groups (Scheme 1).…”

Far‐Red and Near‐Infrared Boron Schiff Bases (BOSCHIBAs) Dyes Bearing Anionic Boron Clusters

“…[35] On the other hand, another remarkable anionic boron clusters is the closo-dodecaborate dianion, [B 12 H 12 ] 2À , and derivatives, [36] which have also demonstrate to have high chemical stability and hydrolytic capacity especially for their sodium salts, [37][38][39] which along with the low toxicity, [40] make them ideal candidates to design pharmacophores. [41][42][43][44] Despite the enormous advance of highly emissive carborane-based compounds over the past decades, the development of luminescent systems bearing anionic boron clusters, in especial COSAN and closo-dodecaborate, has been very limited, [45] and only a few examples reported by us [46][47][48][49] and others [50][51][52] are known. In general, all these systems were essentially designed for theragnostic applications, aiming to improve the intracellular boron release required in BNCT combined with fluorescence imaging.…”