A cyclic peptide antenna ligand for enhancing terbium luminescence

We present here a cyclic peptide ligand, cy(WQETR), that binds to the terbium ion (Tb3+) and enhances Tb3+ luminescence intensity through the antenna effect.

Luminescent Sensor Based on Ln(III) Ternary Complexes for NAD(P)H Detection

Ln(III) complexes of macrocyclic ligands are used in medicinal chemistry, for example as contrast agents in MRI or radiopharmaceutical compounds, and in diagnostics using fluorescence imaging. This paper is devoted to a spectroscopic study of Ln(III) ternary complexes consisting of macrocyclic heptadentate DO3A and bidentate 3-isoquinolinate (IQCA) ligands. IQCA serves as an efficient antenna ligand, leading to a higher quantum yield and Stokes shift (250–350 nm for Eu, Tb, Sm, Dy in VIS region, 550–650 nm for Yb, Nd in NIR region). The shielding-quenching effect of NAD(P)H on the luminescence of the Ln(III) ternary complexes was investigated in detail and this phenomenon was utilized for the analytical determination of this compound. This general approach was verified through an enzymatic reaction during which the course of ethanol transformation catalyzed by alcohol-dehydrogenase (ADH) was followed by luminescence spectroscopy. This method can be utilized for selective and sensitive determination of ethanol concentration and/or ADH enzyme activity. This new analytical method can also be used for other enzyme systems coupled with NAD(P)H/NAD(P)+ redox pairs.

The role of the excited state dynamic of the antenna ligand in the lanthanide sensitization mechanism

A fragmentation scheme has been used to describe the photophysical phenomena associated with the antenna effect in organometallic lanthanide complexes. The theoretical protocol allows justifying the sensitization pathways.

Photophysical Investigation of near Infrared Emitting Lanthanoid Complexes Incorporating Tris(2-Naphthoyl)methane as a New Antenna Ligand

A conjugated <i>β</i>-triketone, tris(2-naphthoyl)methane (<b>tnm</b>H), has been synthesized and successfully utilized as an antenna moiety for sensitization of the trivalent lanthanoids Eu³⁺_,Sm³⁺_,Yb³⁺and Nd³⁺, in an isomorphous series of mononuclear complexes formulated as [Ln(<b>tnm</b>)₃(DMSO)₂] (Ln³⁺= Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺and Yb³⁺). The photophysical properties of the materials were characterized as comprehensively as possible, with overall quantum yields, intrinsic quantum yields based on calculated radiative decays, and sensitization efficiencies reported. This investigation improves understanding of the sensitization processes occurring in the near-infrared (NIR) region systems in particular, where quantitative data is currently scarce. In fact, the [Yb(<b>tnm</b>)₃(DMSO)₂] and its deuterated analogue, [Yb(<b>tnm</b>)₃(<i>d₆-</i>DMSO)₂], present high values of overall quantum yield of 4% and 6%, respectively, which makes them useful and readily accessible references for future investigation of NIR-emitting systems.

Photophysical Investigation of near Infrared Emitting Lanthanoid Complexes Incorporating Tris(2-Naphthoyl)methane as a New Antenna Ligand

A conjugated <i>β</i>-triketone, tris(2-naphthoyl)methane (<b>tnm</b>H), has been synthesized and successfully utilized as an antenna moiety for sensitization of the trivalent lanthanoids Eu³⁺_,Sm³⁺_,Yb³⁺and Nd³⁺, in an isomorphous series of mononuclear complexes formulated as [Ln(<b>tnm</b>)₃(DMSO)₂] (Ln³⁺= Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺and Yb³⁺). The photophysical properties of the materials were characterized as comprehensively as possible, with overall quantum yields, intrinsic quantum yields based on calculated radiative decays, and sensitization efficiencies reported. This investigation improves understanding of the sensitization processes occurring in the near-infrared (NIR) region systems in particular, where quantitative data is currently scarce. In fact, the [Yb(<b>tnm</b>)₃(DMSO)₂] and its deuterated analogue, [Yb(<b>tnm</b>)₃(<i>d₆-</i>DMSO)₂], present high values of overall quantum yield of 4% and 6%, respectively, which makes them useful and readily accessible references for future investigation of NIR-emitting systems.

Photophysical investigation of near infrared emitting lanthanoid complexes incorporating tris(2-naphthoyl)methane as a new antenna ligand

Study of a series of lanthanoid complexes reveals that ancillary ligands play a significant role in their photophysical properties.