Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ4 N 3,N 6,N 10,N 13)bis-(perchlorato-κO)nickel(II) from synchrotron data.

The crystal structure of the nickel(II) macrocyclic title complex, trans- [Ni(ClO4)2(C16H38N6)], was analyzed using synchrotron radiation. The coordination environment consists of four nitro-gen atoms from the ligand [Ni-N = 1.9382 (16), 1.9378 (17) Å] and two perchlorate oxygen atoms [Ni-O = 2.878 (3) Å], adopting an octa-hedral geometry with slight tetra-gonal distortion. The structural comparison with its CuII analogue reveals a notable elongation in the axial Ni-O bonds, which is attributed to the steric hindrance of the macrocyclic ligand and weak axial coordination. Supra-molecular inter-actions involving hydrogen bonding further consolidate the three-dimensional crystal packing.