Comparison of carbazole and fluorene donating effects on the two-photon absorption and nitric oxide photo-release capabilities in a ruthenium-nitrosyl complex

Alejandro Enriquez-Cabrera (1, 2) , Pascal G. Lacroix (1) , Isabelle Sasaki (1) , Sonia Mallet-Ladeira (1, 3) , N. Farfan (4) , Rodrigo M. Barba-Barba (5) , Gabriel Ramos-Ortiz (5) , Isabelle Malfant (1, 2)

1 LCC - Laboratoire de chimie de coordination
2 UT3 - Université Toulouse III - Paul Sabatier
3 ICT - Institut de Chimie de Toulouse
4 Facultad de Quimica, Universidad Nacional Autonoma de Mexico
5 CIO - Centro de Investigaciones en Optica

A ruthenium–nitrosyl derivative of formula [RuII(CzT)(bipy)(NO)](PF6)3 [CzT = 4′-(N-ethylcarbazol-3-yl)-2,2′:6′,2′′-terpyridine, bipy = 2,2′-bipyridine] has been synthesized and fully characterized, and compared with the previously reported [RuII(FT)(bipy)(NO)](PF6)3 complex [FT = 4′-(9,9-dihexyl-9H-fluoren-2-yl)-2,2′:6′,2′′-terpyridine]. Additionally, the X-ray crystal structure of [RuII(CzT)(bipy)(NO2)](PF6), the precursor of [RuII(CzT)(bipy)(NO)](PF6)3, is reported. The presence of a tertiary amine in the carbazole unit leads to redshifted charge-transfer transitions towards the electron-withdrawing Ru–NO fragment and hence enhanced two-photon absorption (TPA) properties. In contrast, the quantum yield of the NO· photorelease process is lower for the carbazole-containing complex. The issue of optimization of the TPA versus NO·-release capabilities is addressed.

Mots clés: Ruthenium, Nitrogen oxides, Drug delivery, Density functional calculations, Photochemistry, Electronic structure, Charge transfer

Domaines: Chimie de coordination

Alejandro Enriquez-Cabrera, Pascal G. Lacroix, Isabelle Sasaki, Sonia Mallet-Ladeira, N. Farfan, et al.. Comparison of carbazole and fluorene donating effects on the two-photon absorption and nitric oxide photo-release capabilities in a ruthenium-nitrosyl complex. European Journal of Inorganic Chemistry, 2018, 3-4, pp.531-543. ⟨10.1002/ejic.201700895⟩. ⟨hal-01961814⟩