Luminescent 1-1,3-benzazaphospholes.

2-R-1-1,3-Benzazaphospholes (R-BAPs) are an interesting class of σP heterocycles containing P[double bond, length as m-dash]C bonds. While closely related 2-R-1,3-benzoxaphospholes (R-BOPs) have been shown to be highly photoluminescent materials depending on specific R substituents, photoluminescence of R-BAPs has been previously limited to an example having a fused carbazole ring system. Here we detail the synthesis and structural characterization of a new R-BAP (3c, R = 2,2'-dithiophene), and compare its photoluminescence against two previously reported R-BAPs (3a, R, R' = Me and 3b, R = 2-thiophene).

Three Ways Isolable Carbenes Can Modulate Emission of NH-Containing Fluorophores.

Fluorescent molecules and materials that exhibit emission changes in response to analytes are of great interest across multiple disciplines. Herein, we investigate the response of NH-containing fluorophores carbazole and 2-phenylbenzimidazole () with two representative isolable singlet carbenes. Specifically, -heterocyclic carbene 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene () and cyclic (alkyl)(amino)carbene (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene () were discovered to afford three different types of reaction products with carbazole and .

Adaptive Coordination-Driven Supramolecular Syntheses toward New Polymetallic Cu(I) Luminescent Assemblies.

A thermally activated delayed fluorescence (TADF) tetrametallic Cu(I) metallacycle A behaves as a conformationally adaptive preorganized precursor to afford, through straightforward and rational coordination-driven supramolecular processes, a variety of room-temperature solid-state luminescent polymetallic assemblies. Reacting various cyano-based building blocks with A, a homometallic Cu(I) 1D-helical coordination polymer C and CuM discrete circular heterobimetallic assemblies D (M = Ni, Pd, Pt) are obtained. Their luminescence behaviors are studied, revealing notably the crucial impact of the spin-orbit coupling offered by the central M metal center on the photophysical properties of the heterobimetallic D derivatives.

Can Coordination-Driven Supramolecular Self-Assembly Reactions Be Conducted from Fully Aliphatic Linkers?

The reaction between a preassembled Cu bimetallic molecular clip with a short intermetallic distance and a series of fully aliphatic cyano-capped ditopic linkers with increasing lengths was investigated. It is shown that, depending on the length of the ditopic linkers, the rational design of unprecedented supramolecular compact metallacycles containing fully aliphatic walls is possible. The specific preorganized molecular arrangement of the molecular clip used favors stabilizing interlinker London dispersion interactions, which allow, as the length of the linkers increases, the selective formation of discrete compact metallacycles at the expense of 1D coordination polymers.

Supramolecular assembly of a phosphole-based moiety into nanostructures dictated by alkynylplatinum(ii) terpyridine complexes through non-covalent Pt···Pt and π-π stacking interactions: synthesis, characterization, photophysics and self-assembly behaviors.

A new class of platinum(ii) terpyridine complexes with a phosphole-derived bridging alkynyl ligand have been prepared. The X-ray crystal structure of complex has been determined, and reveals a polymeric zig-zag chain structure with the existence of π-π stacking interactions. The photophysical properties have also been studied, with MLCT/LLCT phosphorescence exhibited in degassed CHCl; the energy of which is varied by the π-conjugation of the terpyridine ligands.

Rigid biimidazole ancillary ligands as an avenue to bright deep blue cationic iridium(iii) complexes.

Herein we report the synthesis and optoelectronic characterisation of three deep blue-emitting cationic iridium complexes, of the form [Ir(dFppy)(2)(N^N)]PF(6), bearing biimidazole-type N^N ancillary ligands (dFppyH = 2-(2,4-difluorophenyl)pyridine). Complex 1 contains the parent biimidazole, biim, while 2 contains a dimethylated analog, dMebiim, and 3 contains an ortho-xylyl-tethered biimidzole, o-xylbiim. We explore a strategy of tethering the biimidazole in order to rigidify the complex and increase the photoluminescent quantum yield, culminating in deep blue (λ(max): 457 nm in MeOH at 298 K) ligand-centered emission with a very high photoluminescent quantum yield of 68% and microsecond emission lifetime.