Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Zaragoza, Instituto de Síntesis QuímicayCatálisis Homogénea (ISQCH), Pedro Cerbuna 12, 50009, Zaragoza, Spain.
Departamento de Química Inorgánica, Escuela de Ingeniería y Arquitectura de Zaragoza, Universidad de Zaragoza, Instituto de Síntesis QuímicayCatálisis Homogénea (ISQCH), Campus Río Ebro, Edificio Torres Quevedo, 50018, Zaragoza, Spain.
Chemistry. 2018 Jul 2;24(37):9377-9384. doi: 10.1002/chem.201800646. Epub 2018 Jun 5.
New bis-pyrazole complexes [Pt(C^C*)(RpzH) ]X, containing a cyclometalated N-heterocyclic carbene ligand (HC^C*=1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene) were prepared as chloride (X=Cl , RpzH: 3,5-Me pzH 1 a, 4-MepzH 2 a, pzH 3 a), perchlorate (X=ClO , 1 b-3 b), or hexafluorophosphate (X=PF , RpzH: 3,5-Me pzH 1 c) salts. The X-ray structure of 1 a showed that the Cl anion is trapped by the cation through two N-H⋅⋅⋅Cl bonds. In solution of methanol, acetone and THF at RT, 1 a-3 a coexist in equilibrium with the corresponding [PtCl(C^C*)(RpzH)] (B) and RpzH species. In CH Cl , this equilibrium takes place just for 2 a and 3 a, but it is completely shifted to the left at 243 and 223 K for 2 a and 3 a, respectively. The low-lying absorption and emission bands were assigned to intraligand (ILCT) charge transfer on the NHC group. Quantum yield measurements in PMMA films revealed that 1 b, 2 b and 1 c are amongst the most efficient blue-light emitters, with values up to 100 %. Proton abstraction from the coordinated 3,5-Me pzH in 1 b by NEt and replacement by Ag afforded a neutral [Pt Ag ] cluster containing Pt→Ag dative bonds.
新型双吡唑配合物[Pt(C^C*)(RpzH) ]X，其中包含一个环金属化 N-杂环卡宾配体（HC^C*=1-(4-(乙氧羰基)苯基)-3-甲基-1H-咪唑-2-亚基），作为氯化物（X=Cl，RpzH：3,5-Me pzH 1a，4-MepzH 2a，pzH 3a）、高氯酸盐（X=ClO，1b-3b）或六氟磷酸盐（X=PF，RpzH：3,5-Me pzH 1c）盐被制备。1a 的 X 射线结构表明，Cl 阴离子通过两个 N-H···Cl 键被阳离子捕获。在甲醇、丙酮和室温下的 THF 溶液中，1a-3a 与相应的[PtCl(C^C*)(RpzH)]（B）和 RpzH 物种处于平衡状态。在 CHCl3 中，这种平衡仅在 2a 和 3a 中发生，但在 243 和 223 K 下，分别完全向左移动。低能吸收和发射带被分配给 NHC 基团上的分子内（ILCT）电荷转移。在 PMMA 薄膜中的量子产率测量表明，1b、2b 和 1c 是最有效的蓝光发射器之一，其值高达 100%。通过 NEt 从配位的 3,5-Me pzH 中提取质子并被 Ag 取代，得到一个含有 Pt→Ag 配位键的中性[Pt Ag] 簇。
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