6533b870fe1ef96bd12cfc0f

RESEARCH PRODUCT

A theoretical study of the intramolecular charge transfer in 4-(dimethylamino)benzethyne

Pedro B. CotoJavier Segarra‐martí

subject

education.field_of_studyPopulationGeneral Physics and Astronomy-Naturwissenschaftliche FakultätPhotochemistryPotential energyBenzonitrilechemistry.chemical_compoundPhotophysicschemistryChemical physicsIntramolecular forceExcited stateCASPT2//CASSCFRelaxation (physics)ddc:530Singlet statePhysical and Theoretical ChemistryPerturbation theoryeducation

description

We have investigated the non-adiabatic relaxation processes occurring in the singlet manifold of 4-(dimethylamino)benzethyne (DMABE){,} a molecule isoelectronic with 4-(dimethylamino)benzonitrile (DMABN) but lacking its characteristic dual fluorescence{,} using multireference perturbation theory methods. The results obtained point out to the existence of a two-fold decay mechanism in which the population of the initially accessed La state bifurcates towards a locally excited (LE) and a [small pi][sigma]* state. Further relaxation to an emitting intramolecular charge transfer (ICT) state is impeded due to the presence of pronounced energy barriers along their associated potential energy surfaces. These results provide further evidence of the role of [small pi][sigma]* states in the non-adiabatic relaxation processes of dialkylaminobenzonitriles.

https://doi.org/10.1039/c4cp03436h