“…Furthermore, in the order going from Mn II to Ni II complex 1 → 4 all M-N distances decrease, which is in agreement with the decreasing ionic radius of complexed metal ions. On the other hand, the M-O distances remain the same for 1-3 and significantly increase in the case of Ni II complex 4 due to the Jahn-Teller effect, 71 which is typical of structurally similar seven-coordinate pentagonal bipyramidal Ni II complexes [NiL1Cl 2 ], 72 [NiL2](ClO 4 ) 2 , 12 [NiL3], 38 [NiL6](ClO 4 ) 2 35 for which the Ni-O distances often exceed 2.5 Å. Thus, the pentagonal bipyramidal geometry of the Ni II centre in 4 is the most distorted one (Ni-O is 2.413(2) and 2.416(2) Å) and this distortion for the second crystallographically independent molecules present in the asymmetric unit is even more pronounced (Ni-O is 2.357(2) and 2.486(2) Å, see Table 1 and Fig.…”