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

Abstract

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 concave-convex chains in which cis-octahedrally coordinated Mn(II) ions are alternately bridged by double EE and double EO bridges. There exist pi-pi 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.

Azido bridge mediated catecholase activity, electrochemistry and magnetic behavior of a dinuclear copper(II) complex of a phenol based “end-off” compartmental ligand

“…The azido bridge is generally antiferromagnetic for the l 1,3 -N 3 (end-to-end, EE) mode, though, in the recent past, some exceptions have been reported [15][16][17][18]. For the l 1,1 -N 3 (end-on, EO) bridging mode, ferromagnetic ordering is established when the Cu-N-Cu angle is small, which has been attributed to a spinpolarization effect [19][20][21][22]. We are reporting herein synthesis, structural characterization of [Cu 2 L 2 (H 2 O) 2 (l 1,1 -N 3 )](NO 3 ) 2 (L = 2,6-bis(N-ethylpyrrolidine-iminomethyl)-4-methyl-phenolato), catecholase activity in DMSO and acetonitrile medium using 3,5-di-tert-butylcatechol (3,5-DTBC) and tetrachlorocatechol (TCC) as substrate, electrochemistry and variable temperate magnetic study and magneto-structural correlations.…”

Intrachain antiferromagnetic exchange in a 1D branched-chain built of two different copper(ii) centres interlinked by end-on azido and phenoxo bridges: electron density map, electrochemical and magnetic properties

“…For instance, the azido bridge between two square pyramidal Cu(II) ions may assume a basal-basal or a basal-apical disposition, which affects the magnetic exchange coupling. [12][13][14][15][16][17][18] The occurrence of a single EO azido bridge, i.e., the case in which there is no bridge between the two metal ions other than the single EO azido group, is very rare. In all reported compounds with such bridges at least another mode of azide coordination is involved in forming the structure, and to the best of our knowledge, no species containing only single EO bridges have been communicated.…”

“…In all reported compounds with such bridges at least another mode of azide coordination is involved in forming the structure, and to the best of our knowledge, no species containing only single EO bridges have been communicated. [12,18] In the present paper, we report, for the first time, the synthesis, crystal structure, electrochemical and magnetic properties of a 1D compound containing only single EO azido bridges between two copper(II) centers with different donor atoms and coordination geometries. The complex is of the formula [Cu2(μ-NAPPR)(μ1,1-N3)2]n where NAPPR -2 is a tetradentate N2O2 donor Schiff base obtained from the condensation of 2-hydroxy-1-naphthaldehyde with 1,3-propanediamine.…”

Synthesis, crystal structure, and magnetic properties of 1D Azido-bridged copper(II) complex

“…Various 1D azido-bridged copper (II) polymeric complexes, which exhibit rich structural architectures showing fascinating magnetic properties, have been documented in recent years [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Among them, few interesting structural 1D copper (II) coordination polymers with ladder-like chain have been reported.…”