S1 2-[(4-Phenylpiperazin-1-yl)methyl]imidazo(di)azines as Selective D 4 -Ligands. Induction of Penile Erection by 2-[4-(2-methoxyphenyl)piperazin-1-ylmethyl]imidazo[1,2- a]pyridine (PIP3EA), a Potent and Selective D 4 Partial Agonist. Cécile Enguehard-Gueiffier, a Harald Hübner, b Ahmed El Hakmaoui, c Hassan Allouchi, d Peter Gmeiner, b Antonio Argiolas, e Maria Rosaria Melis e and Alain Gueiffier a,* a Laboratoire de Chimie Thérapeutique, d Laboratoire de Chimie Physique, EA 3857, Faculté de Pharmacie, 31 avenue Monge, F-37200 Tours, France b Department of Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstraβe 19, D-91052 Erlangen, Germany c Department of Chemistry, University Hassan II Mohammadia, Faculty of Sciences and Techniques, BP 146, Mohammadia 20800, Marocco e Bernard B. Brodie Department of Neurosciences, University of Cagliari, S.P. Sestu-Monserrato, KM 0.700, 09042 Monserrato, Italy. Table of contents X-ray crystallographic data for compound 3a S2 Figure 1. ORTEP for 3a S3 Table 1. Crystal data and structure refinement for 3a. S4 Table 2. Atomic coordinates (x 10 4 ) and equivalent isotropic displacement parameters (Å 2 x 10 3 ) for 3a. S5 Table 3. Bond lengths [Å] for 3a. S6 Table 4. Bond angles [°] for 3a. S8 Purity data of compounds S11