Novel Bimetallic-Dicyanamide Extended Two- and Three-Dimensional Networks through [Cu(rac-CTH)]²⁺ Cation Templation

Abstract

Reaction of [Cu(rac-CTH)] 2þ with dicyanamide and Mn 2þ or Fe 2þ produces three bimetallic extended structures. Complexes 1 and 2, both obtained in the same reaction pot, consist of two different (4,4) two-dimensional (2D) layers, with the [Cu(rac-CTH)(dca)] þ cations noncoordinated and coordinated to the Mn(μ 1,5 -dca) network for 1 and 2, respectively (rac- 5,7,12,12,4,8,. Complex 2 shows an unusual monodentate coordination mode through the central amide nitrogen of the dca ligand which is first reported for a polynuclear complex. The structure of 3 consists of a three-dimensional network which can be described as a stacking of layers made of heptanuclear defective cubane units, very similar to those found in 1. The magnetic properties of 3 are indicative of antiferromagnetic coupling with a magnetic phase change occurring at 19 K.