Bis‐Tridentate‐Cyclometalated Ruthenium Complexes with Extended Anchoring Ligand and Their Performance in Dye‐Sensitized Solar Cells. Issue 5 (6th February 2018)

• Record Type: Journal Article
• Authors: Aghazada, Sadig; Zimmermann, Iwan; Ren, Yameng; Wang, Peng; Nazeeruddin, Mohammad Khaja
• Is Part Of: ChemistrySelect. Volume 3:Issue 5(2018)
• Page Start: 1585
• Page End: 1592
• Publication Date: 2018-02-06
• Subjects: Cyclometalation -- Dye-Sensitized Solar Cells -- Ruthenium Complexes -- Sensitizers; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201703138
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Ruthenium polypyridine complexes with six‐membered chelating rings have recently received significant attention due to their broad absorption spectra and outstanding photophysical characteristics. In this work we present the synthesis and characterization of three new heteroleptic bis ‐tridentate cyclometalated ruthenium complexes, i. e.1 a, 2 a, and3 a, with donating and accepting ligands. Complexes2 a and3 a are coordinated with 2, 6‐di(quinolin‐8‐yl)‐4‐methoxycarbonylpyridine ( dqpCO2 Me ), and1 a with 2, 2':6', 2''‐terpyridine‐4'‐ethoxycarbonyl ( tpyCO2 Et ) accepting ligands. Interestingly, the binding mode of the accepting ligand was found to differ in3 a and2 a . NMR spectra and single crystal XRD data reveal that in3 a one of the quinolines of dqpCO2 Me ligand is cyclometalated, while in2 a the ligand coordinates in an expected fashion similar to tpyCO2 Et . The ester groups in1 a and2 a were hydrolyzed to obtain sensitizers1 and2, which were used in dye‐sensitized solar cells (DSCs) and the device performance with both iodine‐ and cobalt‐based electrolytes was investigated. Complete 1 H, 13 C and 1 H‐ 1 H COSY NMR, and high‐resolution mass analyses of all complexes were conducted. Abstract : 2, 6‐di(quinolin‐8‐yl)pyridine (dqp) has recently attracted much attention as a novel ligand for ruthenium complexes for sensitizing purposes. Their main advantage of ruthenium complexes with dqp over 2:4', 6':2''‐terpyridines (tpy) ligand is the extended chelating ring size, which brings to broader absorption spectra and longer excited state lifetimes. In this work, we have modified the dqp ligand, and together with a donating cyclometalated ligand, a sensitizers suitable for dye‐sensitizer solar cell (DSC) application were obtained. Their performance in DSCs was examined.