The dinuclear Cu(II) complex bridged by a single F -anion has orthogonal Jahn-Teller axes, which induce a ferromagnetic interaction between the intramolecular Cu(II) ions.The Cu(II) ion, which has a d 9 configuration, shows a Jahn-Teller distortion that enables the addition of interesting properties such as flexibility, 1 unsaturated coordination sites, 2 unprecedented bonding modes derived from electrostatic interactions, 3,4 and polar structures, 5 to metal complexes. For example, we have recently developed a synthetic method to introduce polar structures in coordination polymers using Cu(II) ions and weak Lewis-base PF 6 -anions. The resulting polar coordination polymers showed highly selective CO 2 adsorption properties with structural transformations. 5 In this paper, we report the synthesis, crystal structure, and physical properties of the dinuclear Cu(II) complex [Cu 2 F(BF 4 ) 3 (4-phpy) 7 ] (1, 4-phpy = 4-phenylpyridine) bridged by a single F -anion, in which a Jahn-Teller distortion contributes to the formation of a unique structure and properties.Blue crystals of 1 were obtained by slow diffusion of a methanol solution containing Cu(BF 4 ) 2 ·xH 2 O and a toluene solution containing 4-phpy in an H-type glass cell. 6 The bridged F -anion originates from the hydrolysis of one equivalent of the BF 4 -anion, 7 a well-documented phenomenon that has also been utilized to yield coordination compounds with bridged F -anions. 8,9 Fig. 1 ORTEP drawing of 1 (thermal ellipsoids drawn at 50% probability).The hydrogen atoms are omitted for clarity.