Ruthenium and iridium are key components in the most important applications of photoactive complexes, namely, light-emitting devices, photocatalysis, bioimaging, biosensing, and photodynamic therapy. Especially, near-infrared (NIR) emissive materials are required in fiber-optic telecommunications, anticounterfeit inks, night-vision readable displays, and bioimaging. Replacing rare and expensive precious metals with more abundant first-row transition metals is of great interest; however, photophysical properties and the chemical stability of 3d metal complexes are often insufficient. Here, we tackle these challenges with a nonprecious metal polypyridine vanadium(II) complex that shows emission above 1300 nm with excited state lifetimes of up to 760 ns. Strong light absorption in the visible spectral region and exceptional stability in the presence of oxygen enable photocatalysis in water and acetonitrile using green to orange-red light for excitation. This study unravels a new design principle for NIR-II luminescent and photoactive complexes based on the abundant first-row transition metal vanadium.

中文翻译：

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一种近红外 II 发光和光活性钒 （II） 络合物，激发态寿命为 760 ns

钌和铱是光活性络合物最重要应用中的关键成分，即发光装置、光催化、生物成像、生物传感和光动力疗法。特别是，光纤电信、防伪油墨、夜视可读显示器和生物成像需要近红外 （NIR） 发射材料。用更丰富的第一行过渡金属取代稀有和昂贵的贵金属具有极大的兴趣;然而，3D 金属配合物的光物理特性和化学稳定性往往不足。在这里，我们用非贵金属聚吡啶钒 （II） 络合物来应对这些挑战，该配合物的发射波长高于 1300 nm，激发态寿命高达 760 ns。在可见光谱区域具有很强的光吸收性，在氧气存在下具有出色的稳定性，因此可以在水和乙腈中使用绿光到橙红光激发进行光催化。本研究揭示了基于丰富的第一行过渡金属钒的 NIR-II 发光和光活性络合物的新设计原理。