Intersystem crossing rates of single perylene molecules in ortho-dichlorobenzene.

Triplet states can be interesting for optical switching of molecular fluorescence as well as quantum experiments relying on the manipulation of spin states. However, the ground state of molecules is usually a singlet state. It is therefore interesting to study the intersystem crossing (ISC) rates between singlet and triplet states.

Spectroscopy of Single Dibenzoterrylene Molecules in para-Dichlorobenzene.

We study single dibenzoterrylene (DBT) molecules embedded in 1,4-dichlorobenzene (para-dichlorobenzene, pDCB) at 1.2 K. Due to the relatively low melting point of pDCB (53 °C), this host-guest system can be easily prepared from the molten phase.

Design and synthesis of aromatic molecules for probing electric fields at the nanoscale.

We propose using halogenated organic dyes as nanoprobes for electric fields and show their greatly enhanced Stark coefficients using density functional theory (DFT) calculations. We analyse halogenated variants of three molecules that have been of interest for cryogenic single molecule spectroscopy: perylene, terrylene, and dibenzoterrylene, with the zero-phonon optical transitions at blue, red, and near-infrared. Out of all the combinations of halides and binding sites that are calculated, we have found that fluorination of the optimum binding site induces a dipole difference between the ground and excited states larger than 0.