Two organic-inorganic manganese(II) halide hybrids containing protonated N,N’-dialkylthioureas with efficient green-emission

• Published in: Journal of molecular structure 2023-04, Vol.1277, p.134851, Article 134851
• Main Authors: Golovnev, Nicolay N., Gerasimova, Marina A., Ostapenko, Ivan A., Zolotov, Andrey O., Molokeev, Maxim S.
• Format: Article
• Language: English
• Subjects: N,N′-alkylthioureas; Photoluminescence; Quantum yield; Structure; Synthesis; X-ray diffraction; Zero-dimensional hybrid manganese(II) halides
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2022.134851

•Luminescent (C5H13N2S)2[MnBr4] (1) and (C7H17N2S)2[MnBr4] (2) were prepared.•The PLQY of 1 and 2 are 97 ± 7% and 83 ± 7%, respectively.•The high PLQY indicates the absence of noticeable concentration quenching between Mn2+ ions.•The high-performance photoluminescence compounds demonstrated promising applications in photonics. Luminescent (C5H13N2S)2[MnBr4] (1) and (C7H17N2S)2[MnBr4] (2) (C5H12N2S = N,N′-diethylthiourea, C7H16N2S = N,N′-diisopropylthiourea) were prepared via solvothermal method, and the structures of these compounds have been resolved using X-ray single crystal diffraction. The structures consist of electrostatically bound MnBr42− anions and organic C5H13N2S+ and C7H17N2S+ cations. The intermolecular N−H···Br and N−H···S hydrogen bonds additionally stabilize crystal structures of 1-2. Upon excitation over broadband covering the range 265 to 515 nm, these compounds show green emission peaking at 526 nm for 1 and 522 nm for 2, which is assigned to the 4T1→6A1 electronic transition of Mn2+ from isolated within the crystal structures MnBr42− tetrahedra. The photoluminescence quantum yield (PLQY) of powder 1 is 97 ± 7% for excitation at 440 nm and that of powder 2 is 83 ± 7% for excitation at 365 nm. The high PLQY indicates the absence of noticeable concentration quenching at shortest Mn···Mn distance of 8.11 and 8.73 Å between Mn2+ ions within the structures of 1 and 2. The high-performance photoluminescence of 0D (C5H13N2S)2[MnBr4] and (C7H17N2S)2[MnBr4] compounds demonstrated promising applications in photonics. [Display omitted]