Elimination of the chloride ion from the [(PPh₃)AuCl] complex using silver triflate (AgOTf) in the presence of 2,2′-bipyridine R₂bpy (the Au : R₂bpy molar ratio is 2 : 1) in dichloromethane at room temperature leads to dinuclear gold(I) complexes [(PPh₃Au)₂(μ-R₂bpy)](OTf)₂ (R₂bpy = bpy (1), dbbpy (2), CH₃Obpy (3), 3-CO₂CH₃bpy (4), 4-CO₂CH₃bpy (5)) in high yields. The crystal structures for all compounds were determined using X-ray diffraction analysis. In all structures, gold ions are in a typical linear environment, and the bipyridine molecule is twisted, which allows intramolecular aurophilic interactions. Relatively short Au(I)⋯Au(I) contacts (3.1262 (2)–3.400 (1) Å) are found in structures 3–5. DFT calculations show the presence of bond critical points (3, −1) for aurophilic interactions in these structures. In structures 1 and 2, the Au(I)⋯Au(I) distances are noticeably larger and equal to 4.479 (1) and 4.589 (1) Å respectively; there are no bond critical points (3, −1) for aurophilic interactions. All complexes show photoluminescence in solid state at room temperature when excited at 300 nm in a wide spectral range: from blue or blue-green emission (400–460 nm) for 1–4 to orange emission (580 mn) for 5. The lifetimes of the excited state are in the microsecond range which is characteristic of phosphorescence. TD-DFT calculations reveal that electronic transitions of different nature are responsible for the photoluminescence of these compounds.

中文翻译：

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具有扭曲桥接 2,2'-联吡啶配体的双核金 (I) 配合物中的分子内亲金相互作用

在二氯甲烷中，在 2,2'-联吡啶 R ₂ bpy（Au : R ₂ bpy 摩尔比为 2 : 1）的存在下，使用三氟甲磺酸银 (AgOTf)从 [(PPh ₃ )AuCl] 复合物中消除氯离子在室温下产生双核金( I )配合物[(PPh ₃ Au) ₂ (μ-R ₂ bpy)](OTf) ₂ (R ₂ bpy = bpy ( 1 ), dbbpy ( 2 ), CH ₃ Obpy ( 3 ), 3-CO ₂ CH ₃ bpy ( 4 ), 4-CO ₂ CH ₃ bpy ( 5)) 高产。所有化合物的晶体结构均使用 X 射线衍射分析确定。在所有结构中，金离子都处于典型的线性环境中，并且联吡啶分子是扭曲的，这允许分子内发生亲热相互作用。在结构3–5中发现了相对较短的 Au( I )⋯Au( I ) 接触 (3.1262 (2)–3.400 (1) Å) 。DFT 计算显示这些结构中存在亲热相互作用的键临界点 (3, -1)。在结构1和2 中，Au( I )⋯Au( I) 距离明显更大，分别等于 4.479 (1) 和 4.589 (1) Å；亲热相互作用没有键临界点 (3, -1)。当在 300 nm 的宽光谱范围内激发时，所有配合物在室温下均显示固态光致发光：从蓝色或蓝绿色发射 (400-460 nm) 1-4到橙色发射 (580 mn) 5。激发态的寿命在微秒范围内，这是磷光的特征。TD-DFT 计算表明，不同性质的电子跃迁是这些化合物光致发光的原因。