Wang Jie, Jiang Yue, Liu Jiao-Yang, Xu Hai-Bing, Zhang Yue-Xing, Peng Xu, Kurmoo Mohamedally, Ng Seik Weng, Zeng Ming-Hua
Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry & Chemical Engineering, Hubei University, Wuhan, 430062, China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Angew Chem Int Ed Engl. 2021 Oct 4;60(41):22368-22375. doi: 10.1002/anie.202107637. Epub 2021 Sep 2.
The salts {[Ln Ln*(Hhmq) (OAc) (hfac) ] [Ln*(hfac) (OAc)(MeOH)] } (Hhmq=2-methanolquinolin-8-oxide, hfac=hexafluoroacetylacetonate; Ln, Ln*=Er, Gd, Yb) feature a discrete heteronuclear cation consisting of two types of lanthanide atoms. The quinolinoxy O-atom serves as a μ -bridge to two Ln atoms and as a μ -bridge to all three atoms, with metal⋅⋅⋅metal distances being around 3.7 Å. For 1 ([Yb Er] ), near-infrared downshifted luminescence is switched to competitive upconversion luminescence upon irradiation by a 980 nm laser under an extremely low excitation power (0.288 W cm ) through introduction of fluoride ions. The stability of 1 after addition of fluoride was confirmed by powder X-ray diffraction and multistage mass spectrometry, associated with the H NMR of 6 ([La Eu] ). More importantly, the at least 20-fold enhancement of the quantum yield in non-deuterated solvents at room temperature under low power densities (2 W cm ) is the highest among the few molecular examples reported.
盐{[Ln Ln*(Hhmq)(OAc)(hfac)][Ln*(hfac)(OAc)(MeOH)]}(Hhmq = 2 - 甲醇喹啉 - 8 - 氧化物，hfac = 六氟乙酰丙酮；Ln，Ln* = Er、Gd、Yb)具有由两种镧系原子组成的离散异核阳离子。喹啉氧基O原子作为μ桥连接两个Ln原子，并作为μ桥连接所有三个原子，金属···金属距离约为3.7 Å。对于1([Yb Er])，通过引入氟离子，在极低激发功率(0.288 W cm)下用980 nm激光照射时，近红外下移发光转变为竞争性上转换发光。添加氟后1的稳定性通过粉末X射线衍射和多级质谱得到证实，这与6([La Eu])的1H NMR相关。更重要的是，在室温下非氘代溶剂中低功率密度(2 W cm)下量子产率至少提高20倍，这在已报道的少数分子实例中是最高的。
