Structural diversity in the self-assembly of various macrocyclic metallic tectons and 4,4′-biphenyldicarboxylic acid ligand

Abstract

Five new nickel(II) coordination complexes based on macrocyclic metallic tectons and 4,4′-biphenyldicarboxylic acid ligand, namely, [(NiL1)2(4,4′-bpdc)(CH3CN)2]⋅(ClO4)2⋅2CH3CN (1), {[(NiL1)(4,4′-bpdc)]⋅DMF⋅4H2O}n (2) and [(NiL1)2(4,4′-bpdc)(H2O)2][(NiL1)2(4,4′-bpdc)3]⋅14H2O (3), {(NiL2)(4,4′-bpdc)}n (4) and {[(NiL3)(4,4′-bpdc)]⋅8H2O}n (5) (L1=1,3,6,8,12,15-hexaazatricycloeicosane, L2=1,3,6,9,11,14-hexaazatricyclooctadecane and L3=1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradeca) have been synthesized and characterized by single-crystal X-ray diffraction. Each nickel(II) atom in complex 1 shows a [NiN5O] octahedral coordination geometry, where four nitrogen atoms from the hexaazamacrocycle ligand, one nitrogen atom from acetonitrile and one oxygen atom from the 4,4′-biphenyldicarboxylic acid ligand. However, all nickel(II) atoms in complexes 2–5 are six-coordinated with four nitrogen atoms from the hexaazamacrocycle ligand and two oxygen atoms from the 4,4′-biphenyldicarboxylic acid, resulting a [NiN4O2] octahedral coordination geometry. Complex 1 possesses an extended framework structure based on a discrete 0D fragment. Complex 2 contains a 3D supramolecular structure based on two 1D chains arraying uniformly in an ABAB manner. Hydrogen-bonded 1D chains in complex 3 rise to 3D frameworks with ABCABC fashion. Complex 4 features rare plywood structure based on 1D chain. Complex 5 has a 3D framework structure bearing 1D water hexamers chains. In addition, the solid states UV–Vis for complexes 1–5 have been investigated.