Erbium complexes with a fluorinated organic core shell linked to a hydrogen-containing shell, have been synthesized using the click reaction between erbium(III) bis(perfluoro-4-azidophenyl)phosphinate and a series of alkynes. The erbium 1.5 μm emission lifetimes in the hydrogen-containing erbium complexes exceed 140 μs, the longest ever reported in hydrogenated organic erbium systems. The visible sensitisation for erbium emission indicates a successful strategy that broadens the usage of non-fluorinated chromophores in organic erbium systems and allows more choices for ligand functionalization with exceptional efficiency for erbium emission.

New Yb(III) complexes based on the pentachlorotropolonate (pctrop) ligand show enhanced infrared emission when excited in the orange organic chromophore. Yb(pctrop)3(DMF-d7)2 presents the highest reported quantum yield for a nonfluorinated infrared-emitting organolanthanide complex.

Zn(II) complexes of the following new, fluorine-containing, benzothiazole-derived ligands have been synthesized and characterized crystallographically: 2-(3,3,3-trifluoro-2-oxopropyl)benzothiazole (3), 4,5,6,7-tetrafluoro-2-(3,3,3-trifluoro-2-oxopropyl)benzothiazole (4), 4,5,6,7-tetrafluoro-2-(2-hydroxyphenyl)benzothiazole (12), 2-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)-4,5,6,7-tetrafluorobenzothiazole (13), and 2-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)benzothiazole (16); the Cu(II) complex of ligand 4 is also reported. These are analogs of the important photo- and electroluminescent material [Zn(BTZ)2]2, where H-BTZ = 2-(2-hydroxyphenyl)benzothiazole. DFT calculations indicate that HOMO and LUMO energy levels in these materials are substantially lowered by fluorination. The fluorinated ZnL2 complexes are mononuclear (in contrast to the dinuclear, nonfluorinated material [Zn(BTZ)2]2). They easily sublime and show broad visible photoluminescence. A common crystallographic feature is the existence of pairs of fluorinated ZnL2 molecules related by inversion centers, with their π systems facing one another.

It is expected that fluorinated organic erbium(III) complexes, of interest for optical applications at λ = 1.5 μm, have improved performance with respect to hydrogenated counterparts. However, the intrinsic radiative properties (including the absorption/emission line strengths) of organic Er3+ complexes have not been systematically studied and compared up to date. This has precluded the observation of opto-structural correlations as well as a proper characterization of the infrared f-f transitions and thus a lack of meaningful figures for the optical efficiency of these materials at the 1.5 μm emission. We have performed a complete opto-structural correlation study of the oscillator strengths of the f-f transitions of hydrogenated and fluorinated organic erbium(III) complexes, including a Judd-Ofelt analysis. The Judd-Ofelt analysis on the crystals has allowed the study of the interdependence of the chemical nature, structure, and spectroscopic behavior. We observe clear trends that can help the design and understanding of these important infrared emitters for phosphor and opto-electronic applications.

Radical-anions, electrochemically generated in aprotic solvent from C2 symmetric homochiral phenazine derivatives, act as chiral electrogenerated bases (EGBs) in the desymmetrisation by selective deprotonation of a prochiral epoxide (3,4-epoxy-2,3,4,5-tetrahydrothiophene-1,1-dioxide); the anion produced is trapped by mesitoic anhydride. The phenazines may be recovered in high yield by air oxidation. Enantiomeric excesses are modest (8–34%) but this is to our knowledge the first demonstration of such stereoselective electrochemically-initiated deprotonation. The reactivity of phenazine radical-anions as EGBs has also been explored by measurements of the rates of proton transfer; the prochiral epoxide was found to have a kinetic acidity similar to that of the methyltriphenylphosphonium cation.

1,6-Disubstituted phenazine derivatives for use as precursors to electrochemically generated bases have been synthesized from readily available starting materials. Reaction of 1,6-dihydroxyphenazine with 1,10-diododecane, 1,11-diiodo-3,6,9-trioxaundecane or (R,R)-(−)-1,2-bis(3-iodopropoxy)cyclohexane gave planar chiral phenazinophanes containing ether-linked bridges; molecular structures of all these compounds have been determined by X-ray crystallography. Substituted 1,6-diaminophenazines were prepared by palladium-mediated amination of 1,6-dichlorophenazine and acylation of 1,6-diaminophenazine followed by reduction. Reaction of 1,6-bis(alkylamino)phenazines with sebacoyl chloride gave planar chiral phenazinophanes containing amide-linked bridges.

Electrochemical reduction of enantiomerically pure amino- and alkoxy-phenazine derivatives forms strongly basic radical anions which give asymmetric induction in the conversion of 3,4-epoxytetrahydrothiophene-1,1-dioxide 7 into the allylic ester 9 with facile regeneration of the phenazine.

New Yb(III) complexes based on the pentachlorotropolonate (pctrop) ligand show enhanced infrared emission when excited in the orange organic chromophore. Yb(pctrop)3(DMF-d7)2 presents the highest reported quantum yield for a nonfluorinated infrared-emitting organolanthanide complex.