Synthesis and Crystal Structure of the Azide K4[Re6Sei8(N3)a6]·4H2O; Luminescence,Redox, and DFT Investigations of the [Re6Sei8(N3)a6]4– Cluster Unit

The reaction of K₄[Re₆Seⁱ₈(OH)^a₆] · 8H₂O with NaN₃ in water results in the formation of [Re₆Seⁱ₈(N₃)^a]^4– units that crystallize with K⁺ and H₂O to form K₄[Re₆Seⁱ₈(N₃)^a₆] · 4H₂O [P2₁/c (N°14), a = 9.0595(3) Å, b = 13.2457(4) Å, c = 13.2040(5) Å, β = 94.472(1)°]. In the solid state, the unit is characterized by N₃ linear groups forming bond angles of roughly 120° with the Re₆ cluster. The positions of the ν_as and ν_sy bands as well as N–N–N deformation modes of the N₃ groups are discussed. Luminescence properties of the [Re₆Seⁱ₈(N₃)^a]^4– unit were measured in the solid state and in an acetonitrile solution. The redox potential of the [Re₆Seⁱ₈(N₃)^a]^4–/[Re₆Seⁱ₈(N₃)^a]^3– system was measured in acetonitrile. Experimental results were analyzed in the light of density functional theory calculations.     

Brilliant BODIPY-fluorene Copolymers With Dispersed Absorption and Emission Maxima

Four systems 1a - d were prepared to investigate the optical properties of copolymers comprised of polyfluorene doped with BODIPY-based fluors. The underlying hypothesis was energy harvested via the strong absorptivity of the major component, fluorine, would be primarily emitted from the BODIPY parts at much higher wavelengths. Optimization of the polymerization process as a function of the mol % of BODIPY, indicated that the brightest polymers were formed when approximately 4 fluorene units were co-polymerized with every BODIPY precursor. These polymers were cast into nanoparticles of ca 40 nm diameter. Treatment of clone 9 rat liver cells with suspensions of these particles resulted in uptake without encapsulation in lysosomes, or organelle targeting.