A Crystalline Copper(II) Coordination Polymer for the Efficient Visible-Light-Driven Generation of Hydrogen

• Published in: Angewandte Chemie (International ed.) Vol. 55; no. 6; pp. 2073 - 2077
• Main Authors: Dong, Xi-Yan, Zhang, Mei, Pei, Ru-Bo, Wang, Qian, Wei, Dong-Hui, Zang, Shuang-Quan, Fan, Yao-Ting, Mak, Thomas C. W.
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 05.02.2016; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Catalysts; Charge transfer; coordination polymer; Copper; Copper compounds; Crystal structure; Decay; dyes/pigments; Emission; Evolution; Fluorescence; Hydrogen; Ligands; Light effects; Mathematical analysis; Nodes; photochemistry; Photoelectric effect; Photoelectric emission; Quenching; Rhodamine; Separation; Stacking; Voltammetry; dyes/pigments; copper; hydrogen; photochemistry; coordination polymer
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201509744

A crystalline coordination polymer (CP) photocatalyst (Cu‐RSH) which combines redox‐active copper centers with photoactive rhodamine‐derived ligands remains stable in acid and basic solutions from pH 2 to 14, and efficiently catalyzes dihydrogen evolution at a maximum rate of 7.88 mmol g−1 h−1 in the absence of a mediator and a co‐catalyst. Cyclic voltammetry, control experiments, and DFT calculations established that copper nodes with open coordination sites and favorable redox potentials, aided by spatially ordered stacking of rhodamine‐based linkers, account for the high catalytic performance of Cu‐RSH. Emission quenching, time‐resolved fluorescence decay, and transient photocurrent experiments disclosed the charge separation and transfer process in the catalytic system. The present study demonstrates the potential of crystalline copper CPs for the practical utilization of light. On active duty: High activity for the generation of hydrogen has been found on irradiating a crystalline coordination polymer containing redox‐active copper centers and rhodamine‐derived organic linkers with visible light. The ordered stacking of the linkers induced rapid transfer of photogenerated electrons to the copper nodes, which have open coordination sites and a favorable redox potential for reducing protons to dihydrogen.