Investigations on the Synthesis, Structures, and Properties of New Copper(I) 2,3-Dimethylpyrazine Coordination Compounds

Abstract

Five new coordination compounds were prepared, structurally characterized, and investigated for their thermal properties. In the structure of the ligand-rich 4:9 compound, tetra(mu2-chloro)bis(mu2-2,3-dimethylpyrazine-N,N')tetrakis(2,3-dimethylpyrazine-N)tetracopper(I) tris(2,3-dimethylpyrazine)solvate (I), discrete complexes are formed by build up of two [(CuCl-(2,3-dimethylpyrazine)2]2 dimers, which are connected by two 2,3-dimethylpyrazine ligands via mu-N,N' coordination. In the 1:1 compound poly[mu2-chloro-mu2-2,3-dimethylpyrazine-N,N'-copper(I)] (II), (CuCl)2 dimers are found, which are connected by the 2,3-dimethylpyrazine ligands into layers. For this composition, a second polymorphic modification was found (III), which exhibits a different topology of the coordination network and a different packing of the layers. In the most stable 3:2 compound catena[tri(mu2-chloro)bis(mu2-2,3-dimethylpyrazine-N,N')tricopper(I)] (IV), six-membered rings of (CuCl)3 are found, which are connected by the 2,3-dimethylpyrazine ligands into chains. In the ligand-deficient 2:1 compound, poly[di(mu3-chloro)(mu2-2,3-dimethylpyrazine-N,N')dicopper(I)] (V), CuCl double chains are found, which are connected by the 2,3-dimethylpyrazine ligands into layers. On heating, compound I transforms quantitatively into the 3:2 compound IV without the formation of II or III as intermediates. Compound IV is also obtained by heating either the 1:1 compound II or III. On further heating, the 3:2 compound IV loses additional ligands, forming the ligand-deficient 2:1 compound V, which then decomposes into CuCl. The stability, thermal reactivity, and the transition behavior of all compounds were investigated using different thermoanalytical methods. These results are compared with those previously reported for the structurally similar CuCl(2-ethylpyrazine) coordination compounds. The formation and the stability of the different compounds in solution were also investigated.

Luminescence properties of “double-stranded staircase” copper(i) halide coordination polymers with N-containing ligands

“…The syntheses of all studied compounds such as pyrazine, 18 bipyridine, 19 2,3-dimethylpyrazine, 10,20,21 and 2-chloropyrazine 22 coordination polymers were described in detail elsewhere. In a typical preparation, the Cu(I) salt and the ligand (both diluted in acetonitrile) were mixed in 2 : 1 molar ratio and heated in a glass ampoule at 140 1C for several hours.…”

Ferrocenylethynyl - a versatile platform for new molecules to novel materials

“…A range of different architectures broadly categorized as A to D generating network and chain structures shown in E to H have been reported (see Figure 17). These clusters such as rhomboid (CuX) 2 dimers [111,[113][114][115], cubane(CuX) 4 tetramers [114][115][116], infinite (CuX) ∞ zigzag [117][118][119][120] or stair-step polymers [117,118] (X= halide) have been investigated by many research groups for their rich photo-physical properties. Structures with pyridine ligands in particular have been extensively studied for their extraordinary photoluminescence properties [121][122][123][124][125][126][127][128][129][130].…”

Hexabromidotetrakis(μ3-4-pyridiniumthiolato-κ3S:S:S)hexacopper(I)

“…For the isotypic chlorido compound, see: Cheng et al (2004). For related literature, see: Jess et al (2007); Nä ther & Jess (2006); Nä ther et al (2003).…”