Probing the electronic communication of the isocyanide bridge through the luminescence properties of the d9-d9 [ClPt(mu-dppm)2Pt(C triple bond N-PCP)]+ and A-Frame [ClPd(mu-dppm)2(mu-C=N-PCP)PdCl] complexes.
Probing the electronic communication of the isocyanide bridge through the luminescence properties of the d9-d9 [ClPt(mu-dppm)2Pt(C triple bond N-PCP)]+ and A-Frame [ClPd(mu-dppm)2(mu-C=N-PCP)PdCl] complexes.
复制标题
通过 d9-d9 [ClPt(mu-dppm)2Pt(C 三键 N-PCP)] 和 A 框架 [ClPd(mu-dppm)2(mu-C) 的发光特性探测异氰化物桥的电子通讯
作者：
S. Clément;S. Aly;D. Fortin;L. Guyard;M. Knorr;A. Abd;P. Harvey
同双核 d9-d9 ClM(mu-dppm)2MCl2 配合物、1 (M ) Pt) 和 2 (M ) Pd) 与缀合且发光的 PCP-NC 配体 (3, PCP ) [2.2]对环芳烷) 反应，提供相应的 d9-d9 末端 [ClPt(mu-dppm)2Pt(CNsPCP)]Cl (4) 和d8-d8 A-框架[ClPd(mu-dppm)2(mu-CdNsPCP)PdCl] (5)分别为异氰化物络合物。这两种双金属配合物通过IR、1H和31P{1H}NMR以及化学分析进行了表征。红外数据（nu(CN)桥接与末端）揭示了4（2147cm(-1)）的末端异氰化物键合模式和5（1616cm(-1)）的A-框架结构。通过紫外-可见光和发光光谱以及光物理测量研究了游离异氰化物 3 以及同双核配合物 4 和 5 的光学和发射性质。由于有机 PCP-NC 配体意外地同时存在配体内 pipi* 荧光和磷光，以及 77 K 下 4 的较低能量激发 LMCT 态（配体到金属电荷转移）产生的无机 M2 键合 Pt2(mu-dppm)2 中心的发光，表明两个发色团之间的共轭较弱，并且缺乏有效的单线态和三线态能量转移。对于 5，仅观察到 PCP-NC 配体的荧光和磷光带[因为 A 框架 XPd(mu-dppm)2(mu-L)PdX (L ) 异氰化物，X ) 卤化物）不发光]，强调 NtC 桥表现出适度的电子通信特性。
The homodinuclear d9-d9 ClM(mu-dppm)2MCl2 complexes, 1 (M ) Pt) and 2 (M ) Pd) react with the conjugated and luminescent PCP-NC ligand (3, PCP ) [2.2]paracyclophane) to provide the corresponding d9-d9 terminal[ClPt(mu-dppm)2Pt(CNsPCP)]Cl (4) and d8-d8 A-frame [ClPd(mu-dppm)2(mu-CdNsPCP)PdCl] (5) isocyanide complexes, respectively. These two bimetallic complexes were characterized by IR, 1H, and 31P{1H} NMR and bychemical analysis. IR data (nu(CN) bridging vs terminal) reveal a terminal isocyanide bonding mode for 4 (2147cm(-1)) and an A-frame structure for 5 (1616 cm(-1)). The optical and emission properties of the free isocyanide 3as well as those of the homodinuclear complexes 4 and 5 were studied by UV-visible and luminescence spectroscopy and by photophysical measurements. The unexpected presence of simultaneous intraligand pipi* fluorescence and phosphorescence attributable to the organic PCP-NC ligand, as well as luminescence from the inorganic M2-bonded Pt2(mu-dppm)2 center arising from a lower energy excited LMCT state (ligand-to-metal-charge-transfer) for4 at 77 K, indicates a weak conjugation between the two chromophores and an absence of efficient singlet andtriplet energy transfers. For 5, only the fluorescence and phosphorescence bands of the PCP-NC ligand are observed [since the A-frame XPd(mu-dppm)2(mu-L)PdX (L ) isocyanide, X ) halide) is not luminescent], stressing that the NtC bridge exhibits modest electronic communication properties.