Pyridine-based complexes of copper(II) chloride and bromide: ligand conformation effects on crystal structure. Synthesis, structure and magnetic behavior of Cu(2-Cl-3-X′py)₂X₂[X, X′ = Cl, Br]

Abstract

Reaction of copper(II) chloride or bromide with 2-chloro-3-bromopyridine (2 or 2,3-dichloropyridine generates a family of compounds of the general formula L2CuX2 (1-4). X-Ray crystallography shows that the bromide complexes (3-bromo-2-chloropyridine)dibromidocopper(II) (1) and (2,3dichloropyridine)dibromidocopper(II) (3) are particularly unusual in that they crystallize with both the syn-and anti-conformation structures in the same crystal. A review of the literature on complexes of the formula (substituted-pyridine)2CuX2 suggests that these are the first examples of such complexes.The members of the family show a variety of magnetic behaviors and variable temperature magnetic susceptibility data indicate that 1 is essentially paramagnetic (θ = -0.9(1) K) while 3 is weakly ferromagnetic (J = 2.9(1) K). Compound 2 [(3-bromo-2-chloropyridine)dichloridocopper(II)] is well fit by the uniform one-dimensional antiferromagnetic model (J = -19.6(1) K), while compound 4 [(2,3-dichloropyridine)dichloridocopper(II) exhibits weak anti-ferromagnetic interactions (J = -3.68(3) K).

Chiral Motifs in Highly Interpenetrated Metal–Organic Frameworks Formed from Achiral Tetrahedral Ligands**

“…For these three MOFs, the framework structures consist of highly interpenetrated diamondoid-based networks (Figure S10 and S11). These networks are formed by coordinating two pyridine moieties belonging to two different ligands with Cu(II) [43] (Figure 1 and 2, top center). Despite of the different anions and co-ligands (Cl À , H 2 O), the structures of the Chemistry-A European Journal constitutive networks are characterized by adamantane-type cage motifs (Figure 3).…”

A mixed-valence copper chloride coordination polymer composed of one-dimensional cationic and anionic substructures

“…Many of the latter complexes generally consist of chloride and ancillary N-donor ligands coordinated to the copper ion. 36–38 The basic molecular units are linked by short Cu–Cl contacts, leading to the formation of various coordination polymers. In our case, the ionization capacity of HCl and the proton accepting ability of the datrz ligand have been utilized to achieve a unique mixed-valence coordination polymer composed of cationic 6-coordinate Cu II and anionic 4-coordinate Cu I substructures.…”

The crystal structure of bis(ethanol-kO)- bis(6-aminopicolinato-k2 N,O)manganese(II), C16H22O6N4Mn

“…luminescence, biological activity, catalysis and magnetics [5,6]. Therefore, more and more attention has been paid to the study of substituted pyridine based metal complexes.…”