Luminescent Cationic Group 4 Metallocene Complexes Stabilized by Pendant N-Donor Groups

0542202 - ÚFCH JH 2022 RIV US eng J - Journal Article
Dunlop, David - Večeřa, M. - Gyepes, Robert - Kubát, Pavel - Lang, Kamil - Horáček, Michal - Pinkas, Jiří - Šimková, Ludmila - Liška, Alan - Lamač, Martin
Luminescent Cationic Group 4 Metallocene Complexes Stabilized by Pendant N-Donor Groups.
Inorganic Chemistry. Roč. 60, č. 10 (2021), s. 7315-7328. ISSN 0020-1669. E-ISSN 1520-510X
R&D Projects: GA ČR(CZ) GA19-00204S
Institutional support: RVO:61388955 ; RVO:61388980
Keywords : luminiscence * ligands * redox reactions
OECD category: Physical chemistry; Inorganic and nuclear chemistry (UACH-T)
Impact factor: 5.436, year: 2021
Method of publishing: Limited access

Cationic group 4 metallocene complexes with pendant imine and pyridine donor groups were prepared as stable crystalline [B(C6F5)4]− salts either by protonation of the intramolecularly bound ketimide moiety in neutral complexes [(η5-C5Me5){η5-C5H4CMe2CMe2C(R)═N-κN}MCl] (M = Ti, Zr, Hf, R = t-Bu, Ph) by PhNMe2H+[B(C6F5)4]− to give [(η5-C5Me5){η5-C5H4CMe2CMe2C(R)═NH-κN}MCl]+[B(C6F5)4]− or by chloride ligand abstraction from the complexes [(η5-C5Me5)(η5-C5H4CMe2CH2C5H4N)MCl2] (M = Ti, Zr) by Li[B(C6F5)4]·2.5Et2O to give [(η5-C5Me5)(η5-C5H4CMe2CH2C5H4N-κN)MCl]+[B(C6F5)4]−. Solid state structures of the new compounds were established by X-ray diffraction analysis, and their electrochemical behavior was studied by cyclic voltammetry. The cationic complexes of Zr and Hf, compared to the corresponding neutral species, exhibited significantly enhanced luminescence predominantly from triplet ligand-to-metal (3LMCT) excited states with lifetimes up to 62 μs and quantum yields up to 58% in the solid state. DFT calculations were performed to explain the structural features and optical and electrochemical properties of the complexes.
Permanent Link: http://hdl.handle.net/11104/0319998