Abstract

The crystal structure of the novel hydrated CuII salt, [Cu(L)(H2O)2]Cl2·4H2O (L = 3,14-diethyl-2,6,13,17-tetra-aza-tri-cyclo-[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of the [Cu(L)(H2O)2]2+ cation (completed by crystallographic inversion symmetry), one chloride anion and two lattice water mol-ecules. The copper(II) atom exists in a tetra-gonally distorted octa-hedral environment with the four N atoms of the macrocyclic ligand in equatorial and two O atoms from water mol-ecules in axial positions. The latter exhibit a long axial Cu-O bond length of 2.7866 (16) Å due to the Jahn-Teller distortion. The macrocyclic ring adopts a stable trans-III conformation with typical Cu-N bond lengths of 2.0240 (11) and 2.0441 (3) Å. The complex is stabilized by hydrogen bonds formed between the O atoms of coordinated water mol-ecules and the NH groups as donors, and chloride anions as acceptors. The chloride anions are further connected to the lattice water solvent molecules through O-H⋯Cl hydrogen bonds, giving rise to a three-dimensional network structure.

Highlights

  • The macrocycle 3,14-diethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane (C22H44N4, L) contains a cyclam backbone with two cyclohexane subunits and two ethyl groups attached to carbon atoms of the propyl chains that bridge opposite pairs of N atoms

  • We report here synthesis and structural characterization of the novel complex [Cu(L)(H2O)2]Cl2Á4H2O, (I), in order to obtain detailed information on the conformation of the macrocyclic ligand, and the bonding mode of water molecules and chloride anions in the crystal

  • The two ethyl groups on the six-membered chelate rings and the two –(CH2)4– parts of the cyclohexane backbones are anti with respect to the macrocyclic plane

Read more

Summary

Chemical context

The macrocycle 3,14-diethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane (C22H44N4, L) contains a cyclam backbone with two cyclohexane subunits and two ethyl groups attached to carbon atoms of the propyl chains that bridge opposite pairs of N atoms. [Ni(L)(NO3)2] (Subhan & Choi, 2014), [Ni(L)(N3)2] (Lim et al, 2015), [Ni(L)(NCS)2] (Lim & Choi, 2017), [Cu(L)(ClO4)2] (Lim et al, 2006), [Cu(L)(NO3)2] and [Cu(L)(H2O)2](SCN) (Choi et al, 2012) In these complexes, CuII or NiII cations have a tetragonally distorted octahedral coordination environment with the four N atoms of the macrocyclic ligand in the equatorial position and O/N atoms of anions or water molecules in the axial position. The macrocyclic ligands in these CuII and NiII complexes adopt the most stable trans-III conformation. We report here synthesis and structural characterization of the novel complex [Cu(L)(H2O)2]Cl2Á4H2O, (I), in order to obtain detailed information on the conformation of the macrocyclic ligand, and the bonding mode of water molecules and chloride anions in the crystal.

Database survey
Synthesis and crystallization
Findings
Refinement
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call