Synthesis, characterization and photovoltaic studies of 2,2′;6′,2ʺ-terpyridine-based ruthenium complexes with phenylamino, anthranyl and furfuryl substitutions at the 4′-position

Abstract

A series of two heteroleptic ruthenium complexes of the type [Ru(X-tpy)(bpy-COOH)(NCS)](PF₆) (where X-tpy = 4′-(4-N,N-dimethylaminophenyl)-2,2′:6′,2ʺ-terpyridine for complex 1 and 4′-(9-anthryl)-2,2′:6′,2ʺ-terpyridine for complex 2, bpy-COOH = 4,4′-dicarboxy-2,2′-bipyridine) and another heteroleptic ruthenium complex of the type [Ru(X-tpy)(bpy-COOH)(NCS)]Cl (where X-tpy = 4′-(furan-2-yl)-2,2′:6′,2ʺ-terpyridine for complex 3, bpy-COOH = 4,4′-dicarboxy-2,2′-bipyridine) have been synthesized and fully characterized. The effects of these substitutions with varying electronic properties on the resulting ruthenium dyes were studied in relation to their electronic structure and consequent redox chemistry and photovoltaic performance in a DSSC setup. Complex 1 registers a better photovoltaic performance with photon to conversion efficiency (PCE) of (η = 1.41%) with a J_sc value of 2.1 mA cm⁻² and V_oc 0.58 V followed by 2 (η = 0.44%) and 3 (η = 0.13%). The pattern for the photovoltaic performance has been justified with a theoretical analysis of the directionality of the most intense charge transfers taking place in the dyes upon light irradiation.

Graphical Abstract

Keywords:

• 4′-Substituted terpyridines
• ruthenium dyes
• TDDFT
• photovoltaic study

Acknowledgement

SN acknowledges AICTE, New Delhi, India for the AICTE-RPS grant: 8023/RID/RPS-10/Pvt (II Policy)/2011-12. The authors acknowledge the 400 MHz NMR spectral facility and Computational Chemistry facility established in the Chemistry Dept. BIT-Mesra through DST FIST Program (SR/FST/CSI-242/2012). Various analytical services obtained from CIF, BIT-Mesra is greatly acknowledged. JD acknowledges DST-Nano Mission, New Delhi-110016 for funding the simulator system and SB acknowledges UGC New Delhi.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

SN acknowledges AICTE, New Delhi, India for the AICTE-RPS grant: 8023/RID/RPS-10/Pvt (II Policy)/2011-12. The authors acknowledge the 400 MHz NMR spectral facility and Computational Chemistry facility established in the Chemistry Dept. BIT-Mesra through DST FIST Program (SR/FST/CSI-242/2012). Various analytical services obtained from CIF, BIT-Mesra is greatly acknowledged. JD acknowledges DST-Nano Mission, New Delhi-110016 for funding the simulator system and SB acknowledges UGC New Delhi.