title: Three transition-metal complexes with the macrocyclic ligand meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L): [Cu(ClO₄)₂(L)], [Zn(NO₃)₂(L)] and [CuCl(L)(H₂O)]Cl.
abstract: The three transition-metal complexes, (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)bis(perchlorato-κO)copper(II), [Cu(ClO₄)₂(C₁₈H₄₀N₄)], (I), (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)bis(nitrato-κO)zinc(II), [Zn(NO₃)₂(C₁₈H₄₀N₄)], (II), and aquachlorido(meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)copper(II) chloride, [CuCl(C₁₈H₄₀N₄)(H₂O)]Cl, (III), are described. The molecules display a very similarly distorted 4+2 octahedral environment for the cation [located at an inversion centre in (I) and (II)], defined by the macrocycle N₄ group in the equatorial sites and two further ligands in trans-axial positions [two O-ClO₃ ligands in (I), two O-NO₂ ligands in (II) and one chloride and one aqua ligand in (III)]. The most significant difference in molecular shape resides in these axial ligands, the effect of which on the intra- and intermolecular hydrogen bonding is discussed. In the case of (I), all strong hydrogen-bond donors are saturated in intramolecular interactions, while weak intermolecular C-H∙∙∙O contacts result in a three-dimensional network. In (II) and (III), instead, there are N-H and O-H donors left over for intermolecular interactions, giving rise to the formation of strongly linked but weakly interacting chains.
authors.affiliation: University of Chittagong, Chittagong 4331, Bangladesh.
authors.forename: Sabina
authors.initials: S
authors.lastname: Yasmin
authors.forename: Sebastián
authors.initials: S
authors.lastname: Suarez
authors.forename: Fabio
authors.initials: F
authors.lastname: Doctorovich
authors.forename: Tapashi G
authors.initials: TG
authors.lastname: Roy
authors.forename: Ricardo
authors.initials: R
authors.lastname: Baggio
mesh_terms: D000473:Alkanes / Q000138:chemical synthesis / Q000737:chemistry; D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008024:Ligands; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015032:Zinc / Q000737:chemistry*
chemical_list: D000473:Alkanes; D001372:Aza Compounds; D056831:Coordination Complexes; D008024:Ligands; D047028:Macrocyclic Compounds; C024713:n-tetradecane; D003300:Copper; D015032:Zinc
keywords: biologically important compounds; chiral compounds; crystal structure; macrocycles