Crystal structures, spectroscopic characterization, and Hirshfeld surface analyses of three constrained cyclam compounds with perchlorate counteranions

Abstract

Three constrained cyclam compounds with perchlorate anions, 3,14-diethyl-2,6,13,17-diazadiazoniatricyclo[16.4.0.07,12]docosa-2,13-diene diperchlorate [H2L1](ClO4)2 (1), 3,14-diethyl-2,13-diaza-6,17-diazoniatricyclo(16.4.0.07,12)docosane [H2L2](ClO4)2 (2), and bis(3,14-diethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane) di(sodium perchlorate) (L2)2·2NaClO4 (3), have been characterized by elemental analysis and single-crystal X-ray diffraction studies, as well as IR, Raman, and NMR spectroscopy. The asymmetric units of compounds 1 and 2 contain one half dication of [H2L1]2+ or [H2L2]2+ and one perchlorate anion, whereas the asymmetric unit of compound 3 comprises two free L2 molecules, two sodium cations, and two perchlorate anions. The ClO4− ions in 1 and 2 are doubly disordered about a noncrystallographic local threefold axis, and the two ClO4− ions in 3 are fully occupied, although distorted by interactions with adjacent Na+ ions and ligand NH groups. In 1 and 2, the crystals are stabilized by 3D networks of NH⋯O and NH⋯N hydrogen bonds, whereas the crystal structure of 3 is maintained by NH⋯N hydrogen bonds and Na+⋯O/N ion-dipole interactions. Hirshfeld surface analyses with 2D fingerprint plots reveal that the H⋯H and O⋯H interactions are the main intermolecular interactions.