Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, CH-4058 Basel, Switzerland.
Chimie ParisTech, PSL University CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, 11 rue Pierre et Marie Curie, F-75005 Paris, France.
Molecules. 2019 Oct 31;24(21):3934. doi: 10.3390/molecules24213934.
Heteroleptic [Cu(BIPHEP)(N^N)][PF] complexes (BIPHEP = 1,1'-biphenyl-2,2'-diylbis(diphenylphosphane)), in which N^N is 2,2'-bipyridine (bpy), 6-methyl-2,2'-bipyridine (6-Mebpy), 6-ethyl-2,2'-bipyridine (6-Etbpy), or 5,5'-dimethyl-2,2'-bipyridine (5,5'-Mebpy), have been synthesized and characterized using multinuclear NMR spectroscopies and electrospray ionization mass spectrometry. The single crystal structures of [Cu(BIPHEP)(bpy)][PF]∙CHCl, [Cu(BIPHEP)(5,5'-Mebpy)][PF]∙CHCl, [Cu(BIPHEP)(6-Mebpy)][PF]∙EtO∙0.5HO and [Cu(BIPHEP)(6-Etbpy)][PF] confirm distorted tetrahedral {Cu(P^P)(N^N)} coordination environments. Each compound shows a quasi-reversible Cu/Cu process. In deaerated solution, the compounds are weak emitters. Powdered samples are yellow emitters ( in the range 558-583 nm) and [Cu(BIPHEP)(5,5'-Mebpy)][PF] exhibits the highest photoluminescence quantum yield (PLQY = 14%). On cooling to 77 K (frozen 2-methyloxolane), the emission maxima are red-shifted and the excited state lifetimes increase from < 8 μs, to values of up to 53 μs, consistent with the compounds with N^N = 6-Mebpy, 6-Etbpy and 5,5'-Mebpy exhibiting thermally activated delayed fluorescence (TADF).
具有不同配体的 [Cu(BIPHEP)(N^N)][PF] 配合物（BIPHEP = 1,1'-联苯-2,2'-二基双（二苯基膦）），其中 N^N 是 2,2'-联吡啶（bpy）、6-甲基-2,2'-联吡啶（6-Mebpy）、6-乙基-2,2'-联吡啶（6-Etbpy）或 5,5'-二甲基-2,2'-联吡啶（5,5'-Mebpy），已通过多核 NMR 光谱和电喷雾电离质谱法进行了合成和表征。[Cu(BIPHEP)(bpy)][PF]∙CHCl、[Cu(BIPHEP)(5,5'-Mebpy)][PF]∙CHCl、[Cu(BIPHEP)(6-Mebpy)][PF]∙EtO∙0.5HO 和 [Cu(BIPHEP)(6-Etbpy)][PF] 的单晶结构证实了扭曲的四面体形 {Cu(P^P)(N^N)} 配位环境。每个化合物都表现出准可逆的 Cu/Cu 过程。在脱氧溶液中，这些化合物是弱发光体。粉末样品呈黄色发光体（在 558-583nm 范围内），[Cu(BIPHEP)(5,5'-Mebpy)][PF] 的光致发光量子产率最高（PLQY = 14%）。冷却至 77 K（冷冻 2-甲氧基乙醇）时，发射峰红移，激发态寿命从 <8μs 增加到高达 53μs，与 N^N = 6-Mebpy、6-Etbpy 和 5,5'-Mebpy 的化合物一致，表现出热活化延迟荧光（TADF）。
