Carbazole-functionalized dipicolinato Ln(III) complexes show two-photon excitation and viscosity-sensitive metal-centered emission

Author(s)

Monteiro, Jorge H. S. K. ; Fetto, Natalie R. ; Tucker, Matthew J. ; Sigoli, Fernando A. ; de Bettencourt-Dias, Ana

• Document type: Journal article
• Source: Journal of Luminescence; v. 245, p. 6-pg., 2022-05-01.

Abstract

Eu-III and Yb(III )complexes with the carbazole-dipicolinato ligand dpaCbz(2-), namely K-3[Eu(dpaCbz)(3)] and K-3[Yb (dpaCbz)(3)], were isolated. The Eu-III complex displayed metal-centered emission upon one-photon excitation with a sensitized emission efficiency Phi(L)(Ln) of 1.8 +/- 0.3%, corresponding to an intrinsic emission efficiency Phi(Ln)(Ln) of 46% and a sensitization efficiency of eta(sens) 3.9%, with an emission lifetime of the emissive state r of 1.087 +/- 0.005 ms. The Yb-III complex displayed Phi(L)(Ln) of 0.010 +/- 0.001%, and a r of 2.32 +/- 0.06 mu s The Eu-III-centered emission was sensitized as well upon two-photon excitation and a two-photon absorption cross-section sigma(2PA) of 63 GM at 750 nm was determined for the complex. The one- or two-photon sensitized emission intensity of the Eu-III complex changes by more than two-fold when the solvent viscosity is varied in the range 0.5-200 cP and the emission is independent of dissolved oxygen. The Yb-III complex displays a change in emission intensity as well. However, in this case, a dependence of the emission intensity on dissolved oxygen content was observed. (AU)

• FAPESP's process: 14/50906-9 - INCT 2014: in Functional Complex Materials
• Grantee: Fernando Galembeck
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/22127-2 - Development of novel materials strategic for integrated analytical devices
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Projects - Thematic Grants