Heteronuclear Complexes of Macrocyclic Oxamide with Co-ligands:  Syntheses, Crystal Structures, and Magnetic Properties

Abstract

Four heteronuclear complexes Mn(CuL)2(SCN)2 (1), {[Mn(CuL)2(mu-dca)2].2H2O}n (2), Zn(CuL)2(SCN)2 (3), and [Fe(CuL)(N3)2]2 (4) incorporating macrocyclic oxamide ligands have been synthesized and structurally characterized. L is the dianion of diethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo[1,4,8,11]-tetraazacyclotetradecine-13,18-dicarboxylate, and dca is the dicyanamide. The structure of 1 or 3 consists of oxamido-bridged trinuclear [MIICuII2] molecules (for 1, M is the manganese(II) ion, and for 3, M is the zinc(II) ion). Both of them consist of 1D supramolecuar chains via pi-pi interactions. The structure of 2 also has the oxamido-bridged trinuclear [MnIICuII2] structure units and consists of 2D layers formed by the linkage of copper(II) and manganese(II) atoms via the oxamido and mu1, 5-dca bridges. Complex 4 consists of oxamido-bridged tetranuclear [FeII2CuII2] molecules and arranges in 1D chains. Different co-ligands may result in different structures in this macrocyclic oxamide system. The variable-temperature magnetic susceptibility measurements (2-300 K) of 1 and 2 both show the pronounced antiferromagnetic interactions between the copper(II) and manganese(II) ions.

[μ3-cis-N-(2-Aminoethyl)-N′-(2-carboxylatophenyl)oxamidato(3−)]bis(2,2′-diamino-4,4′-bi-1,3-thiazole)tetracopper(II) bis(2,4,6-trinitrophenolate)

“…Compared with studies dealing with symmetric N,N 0 -disubstituted oxamide polynuclear systems (Nakatani et al, 1991;Lloret et al, 1992;Santana et al, 2004;Tang et al, 2005), relatively few studies of asymmetric N,N 0 -disubstituted oxamide polynuclear complexes have been reported to date, owing to difficulties in their synthesis (Matović et al, 2005;Zang et al, 2003). However, polynuclear complexes bridged by asymmetric N,N 0 -disubstituted oxamide ligands containing aromatic groups are characterized by connecting into a threedimensional supramolecular structure via hydrogen bonds and stacking, while they have shown outstanding magnetic properties (Yu et al, 1989(Yu et al, , 1991Larionova et al, 1997;Tao, Zang, Mei et al, 2003;Tao et al, 2004;Matović et al, 2005;Zhu et al, 2007), which prompted us to design and synthesize this type of polynuclear complex to explore their particular structures and functionalities.…”

Bis[μ3-cis-N-(2-aminopropyl)-N′-(2-carboxylatophenyl)oxamidato(3–)]bis(2,2′-bipyridine)dichloridotetracopper(II) dihydrate

“…The CuÁ Á ÁCu separations through the oxamide and carboxylate bridges are 5.2096 (4) and 5.1961 (5) Å , respectively. To date, seven cyclic tetranuclear complexes with symmetrical oxamide bridges have been synthesized and structurally characterized (Abbati et al, 1999;Ribas et al, 1998;Zhu et al, 2007). However, the title complex is the first instance of a dissymmetrical oxamide.…”

Two 1D Ladderlike Heterometallic Zinc(II) Coordination Polymers: Syntheses, Crystal Structures, and Fluorescence Properties

“…Especially, multi-dimension heterometallic polymers have been only rarely synthesized. [33][34][35][36][37][38][39][40][41] On the other hand, coordination polymers have been reported to have the ability to adjust the emission wavelength and intensity of organic materials through incorporation of metal atoms, especially for d 10 metal atoms. [42] In this paper, isophthalic acid and ML macrocyclic units have been as potential bridging ligands to react with Zn A perspective view of the structure is depicted in Figure 1a.…”