Crystal structure of [2,13-bis(acetamido)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-κ4N]silver(II) dinitrate from synchrotron X-ray data

Abstract

The asymmetric unit of the title compound, [Ag(C24H46N6O2)](NO3)2 [C24H46N6O2 is (5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-2,13-diyl)diacetamide, L], consists of one independent half of the [Ag(C24H46N6O2)]2+ cation and one nitrate anion. The Ag atom, lying on an inversion centre, has a square-planar geometry and the complex adopts a stable trans-III conformation. Interestingly, the two O atoms of the pendant acetamide groups are not coordinated to the AgII ion. The longer distance of 2.227 (2) Å for Ag—N(tertiary) compared to 2.134 (2) Å for Ag—N(secondary) may be due to the effects of the attached acetamide group on the tertiary N atom. Two nitrate anions are very weakly bound to the AgII ion in the axial sites and are further connected to the ligand of the cation by N—H...O hydrogen bonds. The crystal packing is stabilized by hydrogen-bonding interactions among the N—H donor groups of the macrocycle and its actetamide substituents, and the O atoms of the nitrate anions and of an acetamide group as the acceptor atoms.

Keywords

• crystal structure
• macrocycle
• synchrotron radiation
• silver(II) complex
• nitrate ion
• trans-III conformation
• hydrogen bonding