Synthesis, self-assembly and nonlinear optical activity of selenium-annulated perylene diimide.

A novel Se-annulated perylene diimide derivative tethered with polyhedral oligosilsesquioxane (POSS) nanoparticles (POSS-2SePDI-POSS) was designed and prepared. The introduction of selenium atoms endows POSS-2SePDI-POSS with significant fluorescence quenching but enhanced excited-state absorption. As a result, POSS-2SePDI-POSS exhibits a distinct reverse saturable absorption characteristic, suggesting its potential application in optical limiting.

Morphology-dependent third-order optical nonlinearity of a 2D Co-based metal-organic framework with a porphyrinic skeleton.

A two-dimensional (2D) Co-based metal-organic framework (MOF) with porphyrinic skeleton forms crystalline plates, flower-shaped clusters, and ultrathin films under optimized conditions, including the use of polyvinylpyrrolidone (PVP) as a surfactant. Ultrathin films demonstrate the best solution-based third-order nonlinear optical properties, featuring a nonlinear transmittance (T) value of 0.54, absorption coefficient (α2) of 9.

Polyhedral oligosilsesquioxane tethered perylene diimide for application in optical limiting and rapid detection of fluoride ions.

A novel perylene diimide derivative equipped with polyhedral oligosilsesquioxane nanocages (POSS-AMPDI) was designed and synthesized for application in optical limiting. Moreover, due to the dual mechanisms of POSS collapse and intermolecular proton transfer, POSS-AMPDI exhibits high sensitivity and rapid selectivity to fluoride ions, with a detection limit as low as 1.64 × 10-8 M.

Rectangle and [2]catenane from cluster modular construction.

Reaction of [Et4N][Tp*WS3] (1) with [Cu(MeCN)4]PF6, CsCl, isonicotinic acid and CuCN, and treatment of [Et4N][Tp*WS3(CuCl)3] (2)/[Et4N][{Tp*WS3Cu3Cl}2(μ-Cl)2(μ4-Cl)] (3) with AgOTf and bpp (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate; bpp = 1,3-di(4-pyridyl)propane) give rise to [Et4N]2[{Tp*WS3Cu3(CN)0.5}2(μ-Cl)2(μ4-Cl)]2(PF6)2 (4) and [(Tp*WS3Cu3)2(μ3-Cl)2(bpp)3]2(OTf)4 (5), respectively. Compounds 4 and 5 feature cluster-based rectangle and [2]catenane architecture, and both exhibit enhanced third-order nonlinear optical responses relative to those of 1.