Universität Potsdam, Institut für Chemie, Anorganische Chemie, Potsdam, Germany.
Dalton Trans. 2012 Sep 14;41(34):10219-27. doi: 10.1039/c2dt30412k. Epub 2012 Jul 9.
A series of new monocationic iridium(III) complexes [Ir(C^N)(2)(N^N)]PF(6) with "large-surface"α,α'-diimin ligands N^N (dap = 1,12-diazaperylene, dmedap = 2,11-dimethyl-1,12-diazaperylene, dipdap = 2,11-diisopropyl-1,12-diazaperylene) and different cyclometalating ligands C^N (piq = 1-phenylisoquinoline, bzq = benzo[h]quinoline, ppz = 1-phenylpyrazole, thpy = 2-(2-thienyl)pyridine, ppy = 2-phenylpyridine, meppy = 2-(4-methylphenyl)pyridine, dfppy = 2-(2,4-difluorophenyl)pyridine) were synthesized. The solid structures of the complexes [Ir(piq)(2)(dap)]PF(6), [Ir(bzq)(2)(dap)]PF(6), [Ir(ppy)(2)(dipdap)]PF(6), [Ir(piq)(2)(dmedap)]PF(6), [Ir(ppy)(2)(dap)]PF(6) and [Ir(ppz)(2)(dap)]PF(6) are reported. In [Ir(piq)(2)(dap)]PF(6), the dap ligand and one of the piq ligands of each cationic complex are involved in π-π stacking interactions forming supramolecular channels running along the crystallographic c axis. In the crystalline [Ir(bzq)(2)(dap)]PF(6)π-π stacking interactions between the metal complexes lead to the formation of a 2D layer structure. In addition, CH-π interactions were found in all compounds, which are what stabilizes the solid structure. In particular, a significant number of them were found in [Ir(piq)(2)(dap)]PF(6) and [Ir(bzq)(2)(dap)]PF(6). The crystal structures of [Ir(ppy)(2)(dipdap)]PF(6) and [Ir(ppy)(2)(dmedap)]PF(6) are also presented, being the first examples of bis-cyclometalated iridium(iii) complexes with phenanthroline-type α,α'-diimin ligands bearing bulky alkyl groups in the neighbourhood of the N-donor atoms. These ligands implicate a distorted octahedral coordination geometry that in turn destabilized the Ir-N(N^N) bonds. The new iridium(iii) complexes are not luminescent. All compounds show an electrochemically irreversible anodic peak between 1.15 and 1.58 V, which is influenced by the different cyclometalated ligands. All of the new complexes show two reversible successive one-electron "large-surface" ligand-centred reductions around -0.70 V and -1.30 V. Electrospray ionisation mass spectrometry (ESI-MS) and collision induced decomposition (CID) measurements were used to investigate the stability of the new complexes. Thereby, the stability agreed well with the order of the Ir-N(N^N) bond lengths.
一系列新型单正离子铱(III)配合物[Ir(C^N)(2)(N^N)]PF(6)，其中 C^N 为“大表面”α,α'-二亚胺配体 N^N（dap = 1,12-二氮杂菲，dmedap = 2,11-二甲基-1,12-二氮杂菲，dipdap = 2,11-二异丙基-1,12-二氮杂菲），N^N 为不同的环金属化配体 C^N（piq = 1-苯基异喹啉，bzq = 苯并[h]喹啉，ppz = 1-苯基吡唑，thpy = 2-(2-噻吩基)吡啶，ppy = 2-苯基吡啶，meppy = 2-(4-甲基苯基)吡啶，dfppy = 2-(2,4-二氟苯基)吡啶）。配合物[Ir(piq)(2)(dap)]PF(6)、[Ir(bzq)(2)(dap)]PF(6)、[Ir(ppy)(2)(dipdap)]PF(6)、[Ir(piq)(2)(dmedap)]PF(6)、[Ir(ppy)(2)(dap)]PF(6)和[Ir(ppz)(2)(dap)]PF(6)的固体结构已被报道。在[Ir(piq)(2)(dap)]PF(6)中，dap 配体和每个阳离子配合物的一个 piq 配体参与了π-π堆积相互作用，形成了沿结晶学 c 轴延伸的超分子通道。在结晶[Ir(bzq)(2)(dap)]PF(6)中，金属配合物之间的π-π堆积相互作用导致二维层状结构的形成。此外，在所有化合物中都发现了 CH-π相互作用，这是稳定固体结构的原因。特别是，在[Ir(piq)(2)(dap)]PF(6)和[Ir(bzq)(2)(dap)]PF(6)中发现了大量的 CH-π相互作用。[Ir(ppy)(2)(dipdap)]PF(6)和[Ir(ppy)(2)(dmedap)]PF(6)的晶体结构也被提出，这是首例带有邻位具有大体积烷基的菲咯啉型α,α'-二亚胺配体的双环金属化铱(III)配合物。这些配体导致扭曲的八面体配位几何形状，从而使 Ir-N（N^N）键不稳定。新的铱(III)配合物不发光。所有化合物在 1.15 至 1.58 V 之间显示出电化学不可逆的阳极峰，这受不同的环金属化配体的影响。所有新的配合物在-0.70 V 和-1.30 V 左右都显示出两个可逆的连续单电子“大表面”配体中心还原。电喷雾电离质谱（ESI-MS）和碰撞诱导解离（CID）测量用于研究新配合物的稳定性。稳定性与 Ir-N（N^N）键长的顺序一致。
