The singlet–triplet energy gap in organic and Pt-containing phenylene ethynylene polymers and monomers

Abstract

Articles you may be interested inDistinguishing triplet energy transfer and trap-assisted recombination in multi-color organic light-emitting diode with an ultrathin phosphorescent emissive layer Wave function instabilities in the cis-trans isomerization and singlet-triplet energy gaps in a push-pull compound J. Chem. Phys. 119, 4112 (2003); 10.1063/1.1592492 Long-range energy transfer of singlet and triplet excitations in dye-doped tris(phenylquinoxaline)We have studied the evolution of the T 1 triplet excited state in an extensive series of phenylene ethynylene polymers and monomers with platinum atoms in the polymer backbone and in an analogous series of all-organic polymers with the platinum͑II͒ tributylphosphonium complex replaced by phenylene. The inclusion of platinum increases spin-orbit coupling so T 1 state emission ͑phosphorescence͒ is easier to detect. For both, the platinum-containing polymer series and for the all-organic polymers, we find the T 1 state to be at a constant separation of 0.7Ϯ0.1 eV below the singlet S 1 state. It is not possible to change this singlet-triplet splitting by altering the size or the charge-transfer character of the polymer repeat unit or by changing the electron delocalization along the polymer backbone. The S 1 -T 1 gap can be increased by confining the S 1 state in oligomers and monomers.

Spin-dependent polaron recombination in conjugated polymers

“…This is in agreement with other theoretical predictions and experimental observations. 29,30 Moreover, the distortion at the center of the SE is shallower than the TE, and the dimerization is also different between the two states. In addition, we note that the value for the exciton singlet-triplet splitting is about 0.7 eV, which is roughly equal to the experimentally observed value in a poly-p-phenylene-vinylene derivative.…”

Use of the Pd-PromotedExtended One-Pot (EOP) Synthetic Protocol for the Modular Construction of Poly-(arylene ethynylene)co-Polymers [?Ar?C?C?Ar??C?C?]n, Opto- and Electro-Responsive Materials for Advanced Technology

“…A one-pot reaction has been carried out by Heitz [27] and other authors, [28] who report an optimization of an efficient in situ sequential TMS deprotection-acetylene/aryl halide coupling procedure devised by Haley [26] to form cyclo-oligoacetylenes. After formation and isolation of the trimethylsilyl intermediate (36), the removal of the trimethylsilyl group and the polycondensation, under phase-transfer conditions, are simultaneously carried out (Route b).…”

Excitation Energy Transfer in Organic Materials: From Fundamentals to Optoelectronic Devices

“…This is further supported by phosphorescence measurements on a series of Pt-containing conjugated polymers, which exhibit greatly increased phosphorescence intensity due to enhanced spin-orbit coupling allowing detection by time-resolved photoluminescence spectroscopy. [67][68][69][70] Sensitized phosphorescence was reported for a soluble phenyl-substituted PPV derivative upon doping the material with a phosphorescent platinum-octaethylporphyrin (PtOEP). [71] Rapid singlet energy transfer to the dopant was observed on excitation of the matrix polymer and fast quenching of the dopant phosphorescence upon excitation of the dopant only.…”