532952-72-0Relevant academic research and scientific papers
Impact of systematic structural variation on the energetics of π-π Stacking interactions and associated computed charge transfer integrals of crystalline diketopyrrolopyrroles
Calvo-Castro, Jesus,Warzecha, Monika,Kennedy, Alan R.,McHugh, Callum J.,McLean, Andrew J.
, p. 4849 - 4858 (2014/11/27)
Control over solid state structure is critical for effective performance in optoelectronic devices bearing π-conjugated charge mediating organic materials. A series of five structurally related N-benzyl-substituted diketopyrrolopyrroles (DPPs) differing solely in 2 out their 60 atoms were synthesized and crystal structures obtained. Systematic variation of the long axis aligned, π-π stacks has been identified within the single crystal structure series and intermolecular interaction energies and charge transfer integrals for the π-π stacks have been computed by means of density functional theory (M06-2X/6-311G(d)). The computed intermolecular interaction energies as well as charge transfer integrals were further investigated utilizing a series of systematically cropped dimer pairs, highlighting the crucial role of the benzyl/halo substitution on stabilization of these π-π dimers. Two of the DPPs, including a new polymorph of a previously reported structure exhibit twice the intermolecular interaction energy and comparable hole transfer integrals to Rubrene, one of the most efficient hole conducting materials known. The computed properties for all of the π-π dimer systems reported herein are consistent with trends predicted by a model system. As such these materials show great promise as charge mediators in organic electronic applications and may be exploited in systematic structure activity based investigations of charge transfer theory.
Metal-free and fluorescent diketopyrrolopyrrole fluorophores for dye-sensitized solar cells
Hablot, Delphine,Islam, Ashraful,Han, Liyuan,Ziessel, Raymond
, p. 462 - 469 (2014/01/17)
Novel metal-free and fluorescent dipyrrolopyrrole (DPP) dyes consisting of a central bis(lactam)-bearing pendent benzyl or branched hydrocarbon groups as solubilizing fragments and two orthogonal side arms (dimethylaminopropyne and benzoate anion) have been designed and synthesized. The UV/Vis absorption spectra recorded in THF are dominated by intense low-energy π-π absorptions centered at 488 nm or 602 nm, respectively, for the phenyl- or thiophene-based DPP dyes. The fluorescence spectra also display broad bands at 555 nm (τF= 0.57 and ΦF=4.6 ns) for the phenyl- and at 624 nm (ΦF=0.31 and ΦF=3.5 ns) for the thiophene-based molecular structures. Under standard global AM 1.5G irradiation a maximum photon-to-electron conversion efficiency of 2.54% was achieved with dye-sensitized solar cells based on nanocrystalline TiO2 (Jsc=7.5 mAcm-2, Voc=0.49 V, and FF=0.70) for the phenyl-based DPP dye and 1.89% (Jsc=7.1 mAcm-2, Voc= 0.41 V, and FF=0.65) for the thiophene-based DPP dye.
Substituted diketopyrrolopyrroles as input energy units in soluble donor-acceptor dyads
Hablot, Delphine,Retailleau, Pascal,Ziessel, Raymond
scheme or table, p. 13346 - 13351 (2011/02/26)
Dual for a transfer! A strategy has been devised for functionalizing fluorescent diketopyrrolopyrroles (DPP) dyes with a borondipyromethene (BODIPY) unit acting as an energy acceptor (see scheme). Quantitative intramolecular electronic energy transfer is
