Analogues of Shibasaki's complexes supported by enantiopure Spinol are synthesized and characterized. The tris(Spinol) Ln III complexes are generated either by ligand deprotonation followed by complexation with lanthanide triflate salts or by in situ deprotonation by Ln(N(SiMe 3 ) 2 ) 3 salts in the presence of additional base. The resulting complexes are found to be luminescent and chiroptically active for both circular dichroism and circularly polarized luminescence (CPL), notably producing strong CPL with dissymmetry factors (g lum ) of up to 0.50, 0.53, and 0.53 for Sm, Tb, and Dy, respectively. The Sm complex is found to be CPL-active in the near-infrared (NIR) region at 980 nm, representing the first report of NIR CPL from Sm. Additionally, the Tb complex, due to efficient sensitization (Φ = 0.846 in tetrahydrofuran) coupled with strong dissymmetry factors, achieves a CPL brightness (B CPL ) of 3760 M −1 cm −1 , the highest reported for any CPL-active compound to date. These are rare examples of compounds that show simultaneous improvement of both CPL metrics (g lum and B CPL ). Solid-state structural analysis of the Spinolate complexes and comparisons to other CPL-active analogues of Shibasaki's complexes also suggest that nondistorted geometries should generate even stronger metrics.

We report the synthesis of lanthanide complexes supported by enantiopure N,N′-bis(methylbipyridyl)bipyrrolidine and subsequent characterization through luminescence studies. Complexes of this ligand with the visibly emissive lanthanides Sm, Eu, Tb, and Dy are luminescent (ϕ f of ≤0.32) and demonstrate strong preferential emission of circularly polarized light in all four cases (|g lum | of ≤0.26). Notably, all four possess at least one transition with a |g lum | of >0.2, and the strongest preferential emission is measured from the complexes of Sm and Dy.

The propensity of octaethyl-7,17-dioxobacteriochlorin toward the formation of transition metal complexes was evaluated. A variety of M II ions (M = Co, Ni, Cu, Zn, Pd, Ag, and Cd) and Fe(III) could be inserted using standard methodologies or, more often, using more forcing conditions. The stable products were spectroscopically characterized. The solid-state structures of the Ni(II), Cu(II), Pd(II), and Ag(II) complexes could also be determined by single crystal Xray diffractometry, whereby the [7,17-dioxobacteriochlorinato] chromophore was found to be largely planar in all cases. The rate of Zn(II) insertion into octaethyl-7,17-dioxobacteriochlorin was less than half that into the corresponding 7-oxochlorin, which itself was about half the rate into the parent octaethylporphyrin. These rate differences reflect the relative decreased basicity of the β-oxo-substituted chromophores and possibly also their decreased conformational flexibility. We compare the basicity of the dioxobacteriochlorin to that of a range of related products of varying reduction state (porphyrin, chlorin, bacteriochlorin), an isomer, and the absence or presence of oxofunctionality, like oxochlorin, chlorin, oxobacteriochlorins, and bacteriochlorin, quantifying the effects of these macrocycle modifications. The work rationalizes earlier reports of the inability of tolyporphin A, a natural product possessing a 7,17dioxobacteriochlorin chromophore, to form metal complexes and provide a more quantitative understanding of the degree of modulation that β-oxo groups have on the coordination properties of porphyrinoids.

Lanthanide complexes have been developed and are reported herein. These complexes were derived from a terpyridine-functionalized calix[4]arene ligand, chelated with Tb3+ and Eu3+. Synthesis of these complexes was achieved in two steps from a calix[4]arene derivative: (1) amide coupling of a calix[4]arene bearing carboxylic acid functionalities and (2) metallation with a lanthanide triflate salt. The ligand and its complexes were characterized by NMR (1H and 13C), fluorescence and UV-vis spectroscopy as well as MS. The photophysical properties of these complexes were studied; high molar absorptivity values, modest quantum yields and luminescence lifetimes on the ms timescale were obtained. Anion binding results in a change in the photophysical properties of the complexes. The anion sensing ability of the Tb(III) complex was evaluated via visual detection, UV-vis and fluorescence studies. The sensor was found to be responsive towards a variety of anions, and large binding constants were obtained for the coordination of anions to the sensor.

The first reported example of circularly polarized luminescence from a chiral, molecular uranyl (UO2 2+) complex in solution is presented. This uranyl chiroptical activity is enabled by complexation with ibuprofen, an enantiopure chiral carboxylate ligand. Salt metathesis between [UO2Cl2(thf)2]2 and the sodium ibuprofenate salts results in the formation of the anionic tris complexes; these complexes are found to be luminescent in solution, both under visible excitation, directly targeting the metal, and through sensitization by UV absorption and energy transfer from the ligand. Each enantiomer displays both circular dichroism and circularly polarized luminescence (CPL) with |g abs| ≤ 8.1 × 10–2 and |g lum| ≤ 8.0 × 10–3 under UV excitation, comparable to chiral transition metal complexes or purely organic emitters. The strength of the CPL emission is found to be comparable following excitation of either the ligand or metal directly. Further, use of CPL allows for resolution of subcomponents of the emission spectrum not previously possible at room temperature using standard fluorescence techniques. Observation of CPL following direct uranyl excitation presents a new tool for probing speciation of uranyl complexes when chiral ligands are used, without the need for synthetic modification to incorporate a suitable chromophore, and could enable the design of improved ligands for uranyl extraction from wastewater.