Interrelationship between the Ancillary Ligand Structure, Acid-Base Properties, and TiO2 Surface Coverage of Ru-II Dyes

Author(s)

Veiga, Elaine Teixeira ; Mueller, Andressa Vidal ; Ramos, Luiz Duarte ; Morelli Frin, Karina Passalacqua ; Polo, Andre Sarto

• Document type: Journal article
• Source: European Journal of Inorganic Chemistry; v. N/A, n. 23, p. 9-pg., 2018-06-22.

Abstract

The effect of donor/acceptor substituents of phenanthroline on the ground and excited state pK(a) of Ru-II tris-heteroleptic compounds, such as cis-[Ru(R-phen)(dcbH(2))(NCS)(2)], where R = H, Me-2, Me-4, Ph-2, and Cbz(2), was investigated, as well as their effect on dye adsorption on a TiO2 surface. It was determined that, aside from the long distance between the substituent and acid site on the molecule, the pK(a) followed the same trend found for uncoordinated ligands; slightly higher pK(a) values were determined for compounds with donor substituents. A linear correlation suggested that the acid-base properties of the dyes have a direct relationship to the amount of dye adsorbed onto the TiO2 surface as well as their molecular volumes. Solar cells prepared using such dyes exhibited IPCE values up to 77% at 520 nm. These results are important for understanding the effect of ancillary ligands on the acid-base properties of ruthenium compounds and the TiO2 surface coverage, which can lead to the development of new and efficient dyes for energy conversion devices. (AU)

• FAPESP's process: 16/25900-2 - Development of perovskite solar cells
• Grantee: Elaine Teixeira Veiga
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 17/18063-0 - Evaluation of Re(I) luminescent compounds in bio-imaging and/or antitumor agents
• Grantee: Karina Passalacqua Morelli Frin
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/24020-9 - Evaluation of processes photoassisted by Ru(II) and Re(I) polypyridyl compounds
• Grantee: Andressa Vidal Muller
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/21993-6 - Evaluation of Ru(II) and Re(I) polypyridyl compounds on photoactive devices
• Grantee: André Sarto Polo
• Support Opportunities: Regular Research Grants