Structural and Magnetic Properties of Three One-Dimensional Azido-Bridged Copper(II) and Manganese(II) Coordination Polymers

Three one-dimensional (1D) azido-bridged coordination polymers of formula [Cu(L)(N3)2]n (1), [Cu2(Me-L)(N3)4]n (2),
and [Mn(L)(N3)2]n (3) have been synthesized and structurally characterized, and their magnetic properties studied,
where L and Me-L are 2-(pyrazol-1-ylmethyl)pyridine and 2-(3-methylpyrazol-1-ylmethyl)pyridine, respectively.
Compound 1 consists of 1D chains in which the Cu(II) ions with a square pyramidal geometry are alternately
bridged by an end-to-end (EE) and an end-on (EO) azido ligands, both adopting a basal−apical disposition. Compound
2 exhibits an unprecedented chain topology built via three different kinds of EO azido bridges. Four Cu(II) ions in
the square pyramidal environment are alternately bridged by single and double EO bridges to form a tetranuclear
cyclic ring, and neighboring rings are interlinked by double EO bridges to generate a “chain of rings”. The intraannular
double azido ions are disposed between metal ions in a basal−basal fashion, and the other two kinds of azido ions
adopt the basal−apical disposition. Compound 3 consists of 1D concavo−convex chains in which cis-octahedrally
coordinated Mn(II) ions are alternately bridged by double EE and double EO bridges. There exist π−π interactions
between the ligands bound to the neighboring Mn(II) ions bridged by the EO bridges. Temperature- and field-dependent magnetic analyses reveal alternate ferromagnetic interactions for 1, dominating ferromagnetic interactions
for 2, and alternating ferro- and antiferromagnetic interactions through the EO and EE azido bridges for 3, respectively.