Unique Magnetic Behavior in a One‐Dimensional Coordination Polymer [Co(tmpyim)₂(tp)]

Abstract

A one dimensional cobalt(II)−radical complex [Co-(tmpyim) 2 (tp)] [tmpyim = 4,4,5,5-tetramethyl-2-(3Ј-pyridyl)-imidazoline-1-oxyl 3-oxide and tp = terephthalate dianion] has been synthesized and characterized by X-ray crystallography. The crystal structure consists of infinite chains ofIn the field of molecular-based magnetic materials, it is fundamentally important to understand the interactions between organic or inorganic spin-carriers and the structurefunction relationships of the magnetic systems.[1Ϫ2] The socalled ''crystal engineering'' approach has been used extensively to control material structure and dimensionality in which extended inorganic structures with organic bridges are synthesized to give coordination polymers or networks.[3Ϫ4]Metal complexes based on pyridyl-substituted nitronyl nitroxides have attracted considerable attention in recent years due to the ability of these radicals to coordinate metal ions and act as magnetic couplers, giving rise to new functional materials with a variety of structural topologies.[5Ϫ12]The terephthalate ligand is a versatile ligand with good binding ability, as exemplified by the formation of polymeric structures.[13Ϫ15] In this paper we report the crystal structure and magnetic properties of a one-dimensional Co II Ϫradical complex with a terephthalate bridge, [Co(tmpyim) 2 (tp)] (1) [tmpyim ϭ 4,4,5,5-tetramethyl-2-(3Ј-pyridyl)imidazoline-1-oxyl 3-oxide and tp ϭ terephthalate dianion).The structure of 1 (Figure 1) shows that each terephthalate dianion binds to two Co II ions in a bis-bidentate mode, leading to a 1-D chain structure. Two tmpyim radical ligands coordinate to the Co II ion through the nitrogen atoms of their pyridyl rings. The Co II ion has a distorted octahedral coordination environment, which is centrosymmetric. Four carboxylato oxygen atoms from two tp ligands form the equatorial plane. The CoϪO bond lengths in the [a]

Two Novel Diamagnetic-metal Coordination Polymers of Nitronyl Nitroxide Radical Incorporating Isophthalate Bridges

“…Several multi-dimensional coordination polymers of metal-nitroxide radicals incorporating terephthalate bridges have been reported [20][21][22][23].…”

The Deposition of Metallopeptide‐Based Coordination Polymers on Graphite Substrates: Effects of Side‐Chain Functional Groups and Local Surface Structure

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Coordination polymers have attracted much attention in the development of new functional materials [1] owing to their many interesting properties such as zeolitic behavior, [2] conductivity, [3] luminescence, [4] magnetism, [5] spin-crossover, [6] and nonlinear optical effects. [7] Stimulated by possible applications, scientists have made impressive progress in the socalled crystal engineering of solid materials.

[8] Yet the equally important controlled assembly of metal-organic polymers on solid surfaces is in its infancy.

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Structure and magnetic properties of a novel heterospin 1-D chain complex containing both Cu(II) and nitroxide radicals as spin branches

“…For the 1-D chain systems with pyridyl-substituted nitronyl nitroxide radicals as spin branches, some systems such as (a) [5][6][7][8][9][10][11][12][13] and (b) [14] (Scheme 1) have been studied to a certain extent, but the systems such as (c) have not been studied so far to the best of our knowledge. In this paper, we gave the first example of a complicated 1-D chain of copper(Ⅱ) ions (c type, Scheme 1) bridged by tcph and coordinated alternatively by nitroxide radicals as spin branches and solvated water as co-ligand, described the synthesis, crystal structure and magnetic properties of this complex, and discussed the magneto-structural correlations of it in detail.…”