Water-stable organic mixed valence (MV) compounds have been prepared by the reaction of reduced bis­(imino)­pyridine ligands (I2P) with the trichloride salts of Al, Ga, and In. The coordination of two tridentate ligands to each ion affords octahedral complexes that are accessible with five ligand charge states: [(I2P0)­(I2P–)­M]2+, [(I2P–)2M]+, (I2P–)­(I2P2–)­M, [(I2P2–)2M]−, and [(I2P2–)­(I2P3–)­M]2–, and for M = Al only, [(I2P3–)2M]3–. In solid-state structures, the anionic members of the redox series are stabilized by the intercalation of Na+ cations within the ligands. The MV members of the redox series, (I2P–)­(I2P2–)­M and [(I2P2–)­(I2P3–)­M]2–, show characteristic intervalence transitions, in the near-infrared regions between 6800–7400 and 7800–9000 cm–1, respectively. Cyclic voltammetry (CV), NIR spectroscopic, and X-ray structural studies support the assignment of class II for compounds [(I2P2–)­(I2P3–)­M]2– and class III for M = Al and Ga in (I2P–)­(I2P2–)­M. All compounds containing a singly reduced I2P– ligand exhibit a sharp, low-energy transition in the 5100–5600 cm–1 region that corresponds to a π*−π* transition. CV studies demonstrate that the electron-transfer events in each of the redox series, Al, Ga, and In, span 2.2, 1.4, and 1.2 V, respectively.

Immobilization of molecular electrocatalysts with retention of catalytic activity is necessary if they will be incorporated into functional photoelectrochemical devices. Most often, immobilization diminishes catalytic performance. Glassy-carbon electrodes covalently modified with [Fe 4 N(CO) 12 ] − are active for electrocatalytic formate production from CO 2 at −1.2 V vs SCE in aqueous solutions buffered at pH 5−9. The modified electrodes are stable for at least 4 days, as demonstrated using cyclic voltammetry experiments. Electrode modification was performed via cycloaddition of alkyne-functionalized [Fe 4 N(CO) 12 ] − with azide-modified glassy-carbon electrodes.

Electrochemical generation of ammonia (NH3) from nitrogen (N2) using renewable electricity is a desirable alternative to current NH3 production methods, which consume roughly 1 % of the world's total energy use. The use of catalysts to manipulate the required electron and proton transfer reactions with low energy input is also a chemical challenge that requires development of fundamental reaction pathways. This work presents an approach to the electrochemical reduction of N2 into NH3 using a coordination complex of aluminum(III), which facilitates NH3 production at −1.16 V vs. SCE. Reactions performed under 15N2 liberate 15NH3. Electron paramagnetic resonance spectroscopic characterization of a reduced intermediate and investigations of product inhibition, which limit the reaction to sub‐stoichiometric, are also presented.

Ligand-based mixed valent (MV) complexes of Al(III) incorporating electron donating (ED) and electron withdrawing (EW) substituents on bis(imino)pyridine ligands (I2P) have been prepared. The MV states containing EW groups are...

BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes) dyes possess intense absorption profiles that can be exploited in various light harvesting applications. However, redox stability and optimization of frontier molecular orbital energies in these dyes are critical for their successful incorporation into new solar cell materials. This article describes the synthesis and characterization of a family of β-substituted BODIPY-ferrocene dyads with push-pull architectures. Designed to stabilize the photo-oxidized BODIPY for dye-sensitized solar cell (DSSC) applications, some deleterious electron transfer behaviours emerged when the ferrocene unit was conjugated to electron deficient BODIPYs. These findings are discussed herein.