To modulate phosphorescent characteristics of Pt₂Au₄ complexes with differently positioned bis(acetylide)naphthalene as a bridging ligand, four isomeric Pt₂Au₄ complexes (1–4) linked by 1,4-bis(acetylide)naphthalene (1), 1,5-bis(acetylide)naphthalene (2), 2,6-bis(acetylide)naphthalene (3), and 2,7-bis(acetylide)naphthalene (4) are elaborately designed and prepared. The Pt₂Au₄ complexes are strongly phosphorescent with the quantum yields as high as 52% in CH₂Cl₂ solutions, in strikingly contrast to weak phosphorescence of bis(acetylide)naphthalene-linked Pt₂ precursors. After the formation of Pt₂Au₄ cluster structures, the increased molecular rigidity dramatically suppresses nonradiative relaxation, which becomes less competitive in contrast to the radiative relaxation of the emitting state, thus resulting in a remarkable enhancement of the quantum yields. Depending on the positions of bis(acetylide) groups attached to naphthalene rings, the phosphorescence of Pt₂Au₄ isomers in CH₂Cl₂ solutions follows 1 (640 nm) → 2 (582 nm) → 3 (567 nm) → 4 (529 nm) to show progressive blue shifts. As demonstrated by photophysical and theoretical studies, vibronic-structured narrow-band emission with a full width at half maxima (fwhm) of 707–1073 cm^–1 is primarily ascribable to ligand-centered triplet states localized at bis(acetylide)naphthalenes, which is dramatically activated upon the formation of the Pt₂Au₄ cluster because the energy harvested by two PtAu₂ cluster moieties is effectively transferred to bridging bis(acetylide)naphthalene. Taking advantage of Pt₂Au₄ complexes 1–4 as phosphorescent emitters, solution-processed OLEDs achieve narrow-band electroluminescence with peak external quantum efficiency of 11.0% for red-emitting complex 1 (fwhm = 45 nm or 1058 cm^–1), 9.4% for orange-emitting complex 2 (fwhm = 33 nm or 960 cm^–1), 13.7% for yellow-emitting complex 3 (fwhm = 33 nm or 1029 cm^–1), and 15.2% for green-emitting complex 4 (fwhm = 24 nm or 848 cm^–1).

中文翻译：

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通过不同位置的双（乙炔）-萘接头调节 Pt2Au4 簇配合物的窄带磷光

为了调节具有不同位置的双（乙炔）萘作为桥接配体的 Pt 2 Au 4 配合物的磷光特性，四个异构 Pt ₂ Au _4配合物_（ 1 – 4 ）通过 1,4-双（乙炔）萘（1）连接，精心设计制备了1,5-双(乙炔)萘( 2 )、2,6-双(乙炔)萘( 3 )和2,7-双(乙炔)萘( 4 )。Pt ₂ Au _{4配合物具有强烈的磷光性，在 CH 2} Cl ₂中的量子产率高达 52%解决方案，与双（乙炔）萘连接的 Pt ₂前体的弱磷光形成鲜明对比。_{Pt 2} Au ₄簇结构形成后，增加的分子刚性显着抑制了非辐射弛豫，与发射态的辐射弛豫相比，非辐射弛豫的竞争性降低，从而导致量子产率显着提高。_{根据与萘环相连的双（乙炔）基团的位置，Pt 2} Au ₄异构体在 CH ₂ Cl ₂溶液中的磷光遵循1 (640 nm) → 2 (582 nm) → 3(567 nm) → 4 (529 nm) 显示渐进蓝移。正如光物理和理论研究所证明的那样，半峰全宽 (fwhm) 为 707–1073 cm ^–1的电子振动结构窄带发射主要归因于位于双（乙炔）萘上的以配体为中心的三重态，这在形成 Pt ₂ Au _{4簇时被显着激活，因为由两个 PtAu 2}簇部分收集的能量被有效地转移到桥接双（乙炔）萘。利用 Pt ₂ Au ₄配合物1 – 4作为磷光发射体，溶液处理的 OLED 实现了窄带电致发光，红色复合物1（fwhm = 45 nm 或 1058 cm ^–1）的峰值外量子效率为 11.0%，橙色复合物2为 9.4% （fwhm = 33 nm 或 960 cm ^–1），黄色发射复合物3（fwhm = 33 nm 或 1029 cm ^–1）为 13.7%，绿色发射复合物4（fwhm = 24 nm 或 848 cm ^–1）为 15.2%。