Synthesis and properties of [Pt(4-CO(2)CH(3)-py)(2)(mnt)]: comparison of pyridyl and bipyridyl-based dyes for solar cells.
The dye complexes [Pt(4-CO(2)R-py)(2)(mnt)] (R = H (3a), CH(3) (3b)) and the precursor complexes [Pt(4-CO(2)R-py)(2)Cl(2)] (2a, 2b) (py = pyridyl) were synthesised, characterised by electrochemical, spectroscopic, spectroelectrochemical (UV-vis-nIR and in situ EPR) and hybrid DFT computational methods and attached to a TiO(2) substrate to determine charge recombination kinetics. The results were compared to the bipyridyl analogues [Pt{X,X'-(CO(2)R)-2,2'-bipyridyl}(mnt)], (X = 3 or 4). The electronic characteristics of the bis-pyridyl complex were found to be different to the bipyridyl complexes making the former harder to reduce, shifting the lowest-energy absorption band to higher energy and showing separate degenerate LUMO orbitals on the two pyridine rings. The latter point determines that the di-reduced pyridyl complex remains EPR active, unlike the bipyridyl analogue. Complex 3a attached to nanocrystalline TiO(2) shows a long charge recombination lifetime in comparison with the analogous complex with the ubiquitous 4,4'-(CO(2)H)(2)-bipyridyl ligand, suggesting that pyridyl complexes may possess some advantage over bipyridyl complexes in dye-sensitised solar cells.
Moorcraft
Lucy P
LP
School of Chemistry, Joseph Black Building, King's Buildings, West Mains Road, Edinburgh, UK.
Morandeira
Ana
A
Durrant
James R
JR
Jennings
James R
JR
Peter
Laurence M
LM
Parsons
Simon
S
Turner
Andrew
A
Yellowlees
Lesley J
LJ
Robertson
Neil
N
D015082:2,2'-Dipyridyl / Q000737:chemistry*; D004396:Coloring Agents / Q000138:chemical synthesis* / Q000737:chemistry; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D007700:Kinetics; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010984:Platinum / Q000737:chemistry*; D011789:Quantum Theory; D012993:Solar Energy; D013056:Spectrophotometry, Ultraviolet
D004396:Coloring Agents; D009942:Organometallic Compounds; D010984:Platinum; D015082:2,2'-Dipyridyl