Synthesis, structure, and magnetism of two tetrahalocuprate salts: (5-TFAPH)2CuX4 (5-TFAP=2-amino-5-trifluoromethylpyridine, X=Cl, Br)

Synthesis, structure and magnetic properties of copper(II) complexes of 2-amino-5-trifluoromethylpyridine (5-TFMAP): (5-TFMAP)2CuX2 (X=Cl or Br), (5-TFMAP)3CuBr2 and [(5-TFMAP)2CuBr2](5-TFMAPH)Br

“…The ligands (a mean plane deviation 0.0647 Å (Cu1) or 0.0733 Å (Cu2)) are all bent slightly away from the apical chloride ion with the Cu ion displaced 0.128(1) Å (Cu1) or 0.109(1) Å (Cu2) from the mean ligand plane toward the apical chloride ion. The 5-TFMAP ligands lie in the anti-conformation (amino substituents directed toward opposite sides of the Cu coordination plane) and are nearly planar with a maximum mean deviation of 0.0172 Å for the constituent ring atoms, comparable to that previously reported [16]. The individual 5-TFMAP ring are canted 65.0(1)°(N11 ring), 59.8(1)°(N21 ring), 58.5(1)°(N31 ring) and 63.5(1)°(N41 ring) from the mean coordination planes of their respective Cu(II) ions.…”

“…The tendency of CF 3 groups to cluster has been observed previously in such complexes as (3-CF 3 py) 2 ZnBr 2 [29] and (5-CF 3 pyridine-2-thiolate) 3 Co [30]. Even the corresponding salts of 5-TFMAP, (5-TFMAPH) 2 CuX 4 [16] show the same type of aggregation ( Fig. 13) with the chloride salt forming layers and the bromide salt forming clusters.…”

“…3270.93 (13) 418.30 (7) 1159.57 (12) (11) 102.73 (13) 87.59 (16) one week, followed by subsequent recrystallization with hot methanol produced crystals of (5-TFMAP) 2 CuBr 2 (2) in 86.83% yield (Scheme 1). Reaction at room temperature in methanol solution produced the tris-complex (5-TFMAP) 3 CuBr 2 (3) instead, even with 2:1 or 1:1 ligand to metal ratios.…”

“…13. Packing diagrams for (5-TFMAPH) 2 CuCl 4 (left) and (5-TFMAPH) 2 CuBr 4 (right) both viewed parallel to the a-axis [16].…”

“…This electronic difference provides an opportunity to further investigate how the electronic structure of the molecule alters the final compound. We have previously reported the synthesis, structure and magnetic properties of the chloride and bromide tetrahalocuprate salts of 5-TFMAP which occurred as a magnetic ladder (chloride, J rung = À13.9(1) K and J rail = À2.9(4) K) and a honeycomb-like lattice (bromide, J $ À1 K) [16] unlike the corresponding 5-MAP compounds where both the chloride and bromide salts crystallized as two-dimensional square magnetic lattices. A hydroxy-bridged Cu(II) dimer with 5-TFMAP has also been characterized both in structure and magnetism [17].…”