Exploiting the optical sensing of fluorophore-tagged DNA nucleobases on hexagonal BN and Al-doped BN sheets: a computational study

The computational result reveals the distinction between absorption and emission phenomena of nucleobases tagged with fluorophore on h-BN and aluminium doped h-BN nanosheets, which can be used as biosensing platforms for nucleic acids.

Towards Understanding Photon Absorption and Emission in MgAl Layered Double Hydroxide

The use of layered double hydroxides (LDHs) in advanced photoactive applications requires tailoring their light absorption, the stabilisation of separated charges and the manipulation of charge recombination behaviour. However, understanding...

New 2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-2,2’-bipyridine-based co-polymer, synthesis, photophysical properties and response to metal cations

A new co-polymer based on fragments of 2-(2-pyridyl)monoazatriphenylene and 2,5-bis (2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione was prepared by using the Sonogashira reaction. The photophysical properties of the polymer were studied. The presence of a strong bathochromic shift of the absorption and emission maxima in comparison with the previously described monomer units is shown. The polymer exhibits an intense “turn-off” response toward Cu2+ cations.

Optical Spectra of Oligofurans: A Theoretical Approach to the Transition Energies, Reorganization Energies, and the Vibronic Activity

There is experimental evidence of high vibronic activity that accompanies the allowed transition between the ground state and the lowest electronic singlet excited state of oligofurans that contain two, three, and four furan rings. The absorption and emission spectra of the three lowest oligofurans measured at liquid nitrogen temperature show distinct fine structures that are reproduced using the projection-based model of vibronic coupling (with Dushinsky rotation included) parameterized utilizing either Density Functional Theory (DFT, with several different exchange-correlation functionals) or ab initio (CC2) quantum chemistry calculations. Using as a reference the experimental data concerning the electronic absorption and fluorescence for the eight lowest oligofurans, we first analyzed the performance of the exchange-correlation functionals for the electronic transition energies and the reorganization energies. Subsequently, we used the best functionals alongside with the CC2 method to explore how the reorganization energies are distributed among the totally symmetric vibrations, identify the normal modes that dominate in the fine structures present in the absorption and emission bands, and trace their evolution with the increasing number of rings in the oligofuran series. Confrontation of the simulated spectra with the experiment allows for the verification of the performance of the selected DFT functionals and the CC2 method.

Optical Spectra of Oligofurans. A Theoretical Approach to the Transition Energies, Reorganization Energies, and the Vibronic Activity

There is experimental evidence of high vibronic activity that accompanies the strongly allowed transition between the ground state and the lowest electronic singlet excited state of oligofurans that contain 2,3, and 4 furan rings. The absorption and emission spectra of the three lowest oligofurans measured in liquid nitrogen temperature show distinct fine structures that are reproduced using the projection-based model of vibronic coupling (with Dushinsky rotation included) parameterized utilizing either DFT (with several different exchange-correlation functionals) or ab initio (CC2) quantum chemistry calculations. Using as reference the experimental data concerning the electronic absorption and fluorescence for the 8 lowest oligofurans we first analyze the performance of the exchange-correlation functionals for the electronic transition energies and the reorganization energies. Subsequently, we use the best functionals alongside the CC2 method to explore how the reorganization energies are distributed among the totally symmetric vibrations, identify the normal modes that dominate in the fine structures present in the absorption and emission bands, and trace their evolution with the increasing number of rings in the oligofuran series. Confrontation of the simulated spectra with the experiment allows for verification of the performance of the selected DFT functionals and the CC2 method.