While the meridional configuration of I and II was preserved in the synthesis of 1 and 2, [3] 3+ was exclusively isolated with a cis-facial coordination of the ligands regardless of whether the synthesis was performed at room temperature (Route A) or at 82°C (Routes B and C, Scheme 1). This contrasts a previous report on [V(ddpd)2] 2+ where the cisfac-isomer was obtained as the kinetic and the mer-isomer the thermodynamic product at 22 and 82 °C, respectively. Similarly, [Co(ddpd)2] 2+ could be isolated as cisfacand mer-isomers by rapid and slow crystallization, respectively. DFT calculations on [3] 3+ suggest only a slight stabilization of the mer-isomer (ca. -0.1 eV) with respect to the cisfacand transfac-isomers which are placed at almost the same energy (Figure ). It is possible that a mixture of isomers forms during the halide substitution reactions. Yet only the cisfac-isomer readily crystallizes enabling its isolation.