Zong-Hui Jiang

Synthesis and magnetism of the first tetranuclear copper(II)–iron(III) complexes of macrocyclic oxamides

Abstract Four novel tetranuclear macrocyclic complexes of the formula [(CuLi)3Fe](ClO4)3·3H2O (i=1–4, Li are the dianions of the [14]N4 and [15]N4 macrocyclic oxamides, namely 2,3-dioxo-5,6:13,14-dibenzo-7,12-bis(ethoxycarbonyl)-1,4,8,11-tetraazacyclotetradeca-7,11-diene, 2,3-dioxo-5,6:13,14-dibenzo-9-methyl-7,12-bis(ethoxycarbonyl)-1,4,8,11-tetraazacyclotetradeca-7,11-diene and 2,3-dioxo-5,6:14,15-dibenzo-7,13-bis(ethoxycarbonyl)-1,4,8,12-tetraazacyclotetradeca-7,12-diene] have been prepared and characterized. These complexes are the first examples of oxamido-bridged Cu(II)–Fe(III) heterometallic species. Cryomagnetic studies on [(CuL1)3Fe](ClO4)3·3H2O (1) and [(CuL3)3Fe](ClO4)3·3H2O (3) (77–300 K) revealed that the Cu(II) and Fe(III) ions interact antiferromagnetically through the oxamido bridge, with the exchange integral J=−30.8 cm−1 for 1 and J=−28.7 cm−1 for 3 based on H =−2J ∑ S i S j . The interaction parameters have been compared with that of the related [Cu3Mn] compound.

The first one-dimensional copper(II)-radical system with alternating double end-on and end-to-end azido bridges

A novel one-dimensional copper(II)-radical complex [Cu(NITmPy)(N3)2(CH3OH)] [NITmPy = 2-(3′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] has been synthesized and structurally characterized. The structure consists of neutral chains of copper(II) ions alternatively bridged by double symmetric end-on and asymmetric end-to-end azide groups. The NITmPy radical ligand coordinates to the copper(II) ions through the nitrogen atom of the pyridyl ring. The magnetic properties were investigated in the temperature range 5–300 K. The complex exhibits ferromagnetic interactions between the copper(II) ions through the end-on and end-to-end azido bridging ligands, and between the copper(II) ion and NITmPy radical. The magnetic behavior is discussed with reference to the crystal structure.

Two novel three-dimensional coordination polymers with [Ag(CN)2]− as bridging ligands: synthesis and structural characterization of {KMn[Ag(CN)2]3(H2O) }n and {Mn[Ag(CN)2]2(bpy)2}n (bpy=4,4′-bipyridine)

Abstract Two novel three-dimensional coordination polymers {KMn[Ag(CN)2]3(H2O)}n 1 and {Mn[Ag(CN)2(bpy)]2}n 2 have been prepared and structurally as well as magnetically characterized. In both compounds, the three-dimensional networks are constructed entirely by coordinative linkages with all the CN− anions of [Ag(CN)2]−, bpy and water ligands involved in bridging and the novel 3-D structure of 1 is unprecedented.

A pentanuclear complex derived from manganese(III) Schiff-based complex and hexacyanoferrate(III): synthesis, structure and magnetic properties

Abstract A cyano-bridged MnIII–FeIII complex, [Mn(salpn)(CH3OH)]4·[Fe(CN)6]ClO4·9(H2O), was prepared and characterized. Single crystal X-ray analysis reveals that the complex assumes a cyano-bridged Mn4Fe unit. The magnetic measurement showed this complex exhibiting ferromagnetic behavior.

Two different three-dimensional microporous framework structures in [Mn2(H2O)4{W(CN)8}.4H2O]n and [Mn2(H2O)4{W(CN)8}(OH).2H2O]n

Two novel cyano-bridged heterobimetallic coordination polymers, [Mn2(H2O)4{W(CN)8}·4H2O]n (1) and [Mn2(H2O)4{W(CN)8}(OH)·2H2O]n (2), have been synthesized from [W(CN)8]n− (n=4, 5) building blocks and structurally characterized, where all the CN groups of [W(CN)8]n− are involved in bridging. Both polymers display different open microporous frameworks of the 3D polygonal type exhibiting zeolite-like properties. The 3D framework of 2 is unprecedented. The study of the magnetic properties showed that both polymers exhibit weakly antiferromagnetic interactions between the adjacent Mn ions through the diamagnetic NC–WIV–CN spacer for 1 and between WV and Mn ions for 2.

A new mixed-ligand copper(II) complex containing azide and 1,10-phenanthroline: crystal structure and properties

A new copper complex, [Cu(phen)2N3]ClO4 (phen = 1,10-phenanthroline), has been synthesized and characterized by X-ray single-crystal structure analysis. The copper atom is five-coordinated with four nitrogen atoms of two phens and one nitrogen atom of the azide to form an intermediate coordination geometry distorted from trigonal bipyramidal (TBP) and square pyramidal (SP). The extended three-dimensional structure is formed through π–π interactions and hydrogen bonds. The IR spectrum, electronic spectrum, magnetic properties and ESR spectrum of the title compound have been studied.

Synthesis, crystal structures and luminescent properties of two supramolecular assemblies containing [Au(CN)2]- building block

Two self-assembled supramolecular architectures {{MnH2O(Phen)2[Au(CN)2]}[Au(CN)2]·0.5C2H5OH·0.5H2O}n (phen = 1, 10-phenanthroline) (1) and [C6H13N4][Au(CN)2]·H2O(C6H13N4 = 4-amide-3, 5-diethyl-1, 2, 4-triazole cation) (2) have been synthesized and structurally characterized. X-ray crystallography revealed a three-dimensional structure of 1 formed by the incorporation of coordinative linkage, aurophilic, hydrogen-bonding and π–π interactions. The 2D structure of 2 is formed by aurophilic and hydrogen-bonding interactions. Both the solid phases and aqueous solutions of 1 and 2 display interesting luminescence at room temperature.

A novel heterospin polynuclear complex containing both macrocyclic and imino nitroxide radical ligands: {[CuL(H2O)](CuL)Mn(IM-2Py)}{[CuL(MeOH)](CuL)Mn(IM-2Py)}(ClO4)4·MeOH

A novel heterospin complex containing both macrocyclic and imino nitroxide radical ligands: {[CuL(H2O)](CuL)Mn(IM-2Py)}{[CuL(MeOH)](CuL)Mn(IM-2Py)}(ClO4)4·MeOH, has been synthesized and its crystal structure determined by X-ray diffraction methods. In order to interpret the exchange interaction of this asymmetric heterospin system which consists of two types of paramagnetic metal centers and a nitroxide radical, a theoretical model has been established. Using this theoretical model the magnetic susceptibility data have been fitted and lead to coupling constant values equal to −7.4 cm−1 (Mn–Rad) and −19.2 cm−1 (Mn–Cu), respectively.

3D porous and 3D interpenetrating triple framework structures constructed by aurophilicity-coordination interplay in {Mn[Au(CN)2]2(H2O)2}n and {KFe[Au(CN)2]3}n

Two cyano-bridged heterobimetallic coordination polymers [Mn[Au(CN)2]2(H2O)2]n (1) and [KFe[Au(CN)2]3]n (2), have been synthesized from [Au(CN)2]- building blocks and structurally characterized. In both complexes aurophilicity play an important role in determining the 3D open microporous framework and the interpenetrating triple framework for 1 and 2, respectively. Both aqueous solutions of 1 and 2 display interesting luminescent properties.

Binuclear complexes of macrocyclic oxamide M(II)-Cu(II) (M = Cu, Ni, Mn): synthesis, crystal structure and magnetic properties

Three oxamido-bridged binuclear M(II)Cu(II) complexes of formulas [Cu(L)Cu(phen)(H 2 O)](ClO 4 ) 2 ( 1 ), [Cu(L)Ni(phen) 2 ](ClO 4 ) 2 ·2H 2 O ( 2 ), and [Cu(L)Mn(bpy) 2 ](ClO 4 ) 2 ( 3 ) have been synthesized, and structurally and magnetically characterized, where L=1,4,8,11-tetraazacyclotradecanne-2,3-dione, phen=1,10-phenanthroline and bpy=2,2′-bipyridine. In the three complexes, the copper atom from the macrocyclic oxamido–copper(II) precursor in a square-planar or axially elongated octahedral environment and the nickel and manganese atoms from 2 and 3 in a distorted octahedral environment are bridged by the oxamidate groups, with Cu⋯Ni and Cu⋯Mn separations of 5.281 and 5.418 A, respectively, while the other copper atom from 1 in square pyramidal coordination geometry, with Cu⋯Cu separation of 5.152 A. The metal–metal separations are consistent with the sequence of decrease of the ion radius of the metal ion. The magnetic properties of all three complexes have been investigated. The χ M T versus T plots for 1 – 3 are typical of antiferromagnetically coupled M(II)Cu(II) pairs (M=Cu, Ni and Mn). The magnitude of spin-exchange interactions in different metal pairs containing the same oxamido bridging ligand is preliminarily discussed.