Crystal structure of [3,10-bis(4-fluorophenethyl)-1,3,5,8,10,12-hexaazacyclotetradecane]nickel(II) diperchlorate

Abstract

The square-planar nickel(II) title complex, [Ni(C24H36F2N6)](ClO4)2 or [NiL](ClO4)2 (L = 3,10-bis(4-fluorophenethyl)-1,3,5,8,10,12-hexaazacyclotetradecane) was synthesized by a one-pot reaction of template condensation and its X-ray crystal structure was determined. The nickel(II) ion lies close by a twofold axis and the complex displays whole-molecule disorder. Ligand L, a hexaazacyclotetradecane ring having 4-fluorophenethyl side chains attached to uncoordinated nitrogen atoms, adopts a trans III (R,R,S,S) configuration. The average Ni—N bond distance is 1.934 (9) Å, which is quite similar to those of other nickel(II) complexes with similar ligands. The nickel(II) ion is located 0.051 (7) Å above the least-squares plane through the four coordinated N atoms. The average C—N bond distance and C—N—C angle involving uncoordinated nitrogen atoms are 1.425 (12) Å and 118.0 (9)°, respectively, indicating a significant contribution of sp2 hybridization for these N atoms. The intermolecular N—H...O, C—H...O/F hydrogen bonds of the complex form a network structure, which looks like a seamless floral lace pattern.

Keywords

• crystal structure
• whole-molecule disorder
• 3,10-bis(4-fluorophenethyl)-1,3,5,8,10,12-hexaazacyclotetradecane
• 4-fluorophenethyl side chain
• nickel(ii) complex
• trans-iii configuration