  New charge transfer crystals of $\pi$-conjugated, aromatic molecules
(phenanthrene and picene) as donors were obtained by physical vapor transport.
The melting behavior, optimization of crystal growth and the crystal structure
is reported for charge transfer salts with (fluorinated)
tetracyanoquinodimethane (TCNQ-F$_x$, x=0, 2, 4), which was used as acceptor
material. The crystal structures were determined by single-crystal X-ray
diffraction. Growth conditions for different vapor pressures in closed ampules
were applied and the effect of these starting conditions for crystal size and
quality is reported. The process of charge transfer was investigated by
geometrical analysis of the crystal structure and by infrared spectroscopy on
single crystals. With these three different acceptor strengths and the two sets
of donor materials, it is possible to investigate the distribution of the
charge transfer systematically. This helps to understand the charge transfer
process in this class of materials with $\pi$-conjugated donor molecules.
