Competition Between Intraligand Charge Transfer (ILCT) and Triplet Sensitization Pathways in 4,7-Disubstituted DAPhen Europium Complexes

Competition Between Intraligand Charge Transfer (ILCT) and Triplet Sensitization Pathways in 4,7-Disubstituted DAPhen Europium Complexes Научная публикация

Журнал

Optical Materials
ISSN: 1873-1252 , E-ISSN: 0925-3467

Вых. Данные

Год: 2027, Том: 181, Номер статьи : 118580, Страниц : DOI: 10.1016/j.optmat.2026.118580

Авторы

Polikovskiy Trofim A. ^1,2,3 , Metlin Mikhail T. ³ , Avagyan Nane A. ⁴ , Zonov Roman V. ⁴ , Lemport Pavel S. ⁴ , Khrustalev Victor N. ^5,6 , Vokuev Mikhail F. ⁴ , Rodin Igor A. ⁴ , Taydakov Ilya V. ^6,3 , Nenajdenko Valentine G. ⁴

Организации

1	Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya Str., Moscow, 105005, Russia
2	Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, 141700, Moscow region, Russia
3	P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospect, 119991, Moscow, Russia
4	Department of Chemistry, Lomonosov Moscow State University, Leninskie gory 1 bld. 3, 119991, Moscow, Russia
5	Department of Inorganic Chemistry, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya street, 117198, Moscow, Russia
6	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospekt, 119991 Moscow, Russia

Symmetric and asymmetric 4,7-disubstituted 1,10-phenanthroline-2,9-diamides were synthesized and coordinated to Eu3+, Gd3+, and Tb3+ nitrates to evaluate the role of intraligand charge transfer (ILCT) in lanthanide ion sensitization. DFT calculations reveal that donor substituents at the 4,7-positions significantly modify charge distribution and metal–ligand bond characteristics. Spectroscopic studies show that pyrrolidine and amino groups induce singlet ILCT states, producing additional excitation bands in the 400–500 nm region. It was shown that ILCT competes with or replaces conventional triplet-mediated energy transfer. Within the investigated series, electronic asymmetry generally suppresses ligand-centered emission while increasing the relative contribution of CT-related excitation; however, both effects are strongly temperature-dependent. This trend is modulated by the nature of the substituents and the excited-state energy alignment. The results identify electronic asymmetry as an important structural factor for tuning charge-transfer pathways and Eu3+ luminescence efficiency in 4,7-disubstituted phenanthroline complexes.

Polikovskiy T.A. , Metlin M.T. , Avagyan N.A. , Zonov R.V. , Lemport P.S. , Khrustalev V.N. , Vokuev M.F. , Rodin I.A. , Taydakov I.V. , Nenajdenko V.G.
Competition Between Intraligand Charge Transfer (ILCT) and Triplet Sensitization Pathways in 4,7-Disubstituted DAPhen Europium Complexes
Optical Materials. 2027. V.181. 118580 . DOI: 10.1016/j.optmat.2026.118580 OpenAlex

Опубликована online:

13 окт. 2026 г.

≡ OpenAlex:

W7220994977