Syntheses and structural characterizations of 24-membered dimetal (Mn, Ni, Fe) macrocyclic complexes and the C–S bond formation between acetylacetone and a mercapto N-heterocycle

Abstract

An organic ligand 2,5-di(3-pentanedionylthio)-1,3,4-thiadiazole (H2L) reacts with metal (Mn, Ni, Fe) salts, resulting in 24-membered dimetal macrocyclic complexes [MnL(H2O)(dmso)](2).2dmso, [NiL(H2O)(dmf)](2).2dmf, [MnL(dmf)2]2 and [Fe2L2(solvent)2(SO4)] (solvent=dmso; H2O ; dmf). Di-manganese macrocyclic complexes [MnL(dmf)(dmso)]2 and [MnL(H2O)2](2).6H2O can also be obtained directly by aerobic assembly reaction of MnCl2, dipotassium 1,3,4-thiadiazole-2,5-dithiolate (K2tdadt) and acetylacetone (H2acac) in various solvents, accompanying a C-S bond formation between acetylacetone and the mercapto N-heterocycle. Disulfide has been considered as the intermediate in the assembly reaction. Meanwhile an assembly reaction including MnCl2, 2-mercaptobenzimidazole and H2acac has produced an organic compound 2-(3-pentanedionylthio)benzimidazole with a new C-S bond. These dimetal complexes have similar macrocyclic structures, in which solvent molecules and sulfate coordinate to the octahedral metal in trans-configuration, whereas a pair of water molecules are located in octahedral cis-positions for owing to a small steric effect. A host cavity of sufficiently large size exists in the macrocyclic structure to trap the solvent molecules and the sulfate anion. The IR spectra have been used to assign the solvent molecules trapped and the sulfate anion which is shown as a bridged bidentate ligand. Thermal analyses show the stability of the macrocyclic backbone below 200 degrees C and gradual release processes of the trapped solvent molecules. Decomposition and oxidation of the dimetal macrocycle backbone occur at 300-500 degrees C, resulting in a metal sulfate. Further decomposition led to metal oxide at 500-600 degrees C.

Bis{μ-3,3′-(1,3,4-thiadiazole-2,5-diyldithio)bis[pentanedionato(1−)]}bis[diaquanickel(II)] dimethylformamide disolvate trihydrate

“…The Ni(II) ion is chelated by the acetyl acetonate (acac) groups forming two non-planar six-membered chelating rings. The acac oxygen atoms which occupied the equatorial plane of the octahedral metal with rather small dihedral angles between the O1-Ni-O2 and O3-Ni-O4 planes is 2.4 (1)°, which is similar to those reported previously (Zhang et al, 2006). The dihedral angles between the thiadiazole ring and the acac-S planes is 85.9 (2)°.…”

3-(Pyridin-4-ylthio)pentane-2,4-dione

“…For applications of -diketones and their derivatives in metallo-supramolecular chemistry, see: Aromí et al (2008); Chen et al (2003;; Domasevitch et al (2006); Massue et al (2005); Soldatov & Ripmeester (2001); Tabellion et al (2001); Vigato et al (2009); Vreshch et al (2003Vreshch et al ( , 2004; Won et al (2007); Zhang et al (2006).…”

“…(2011). E67, o1023 The β-diketones and their derivatives have attracted much attention in recent years, not only for their valuable intrinsic chemical and physical properties but also for their wide applications in metallo-supramolecular chemistry (Aromí & Gamez et al,2008;Massue & Bellec et al, 2005;Soldatov & Ripmeester, 2001;Tabellion & Seidel et al, 2001;Vigato & Peruzzo et al, 2009;Chen & Fronczek et al,2003;Chen & Fronczek et al,2004;Domasevitch & Vreshch, et al, 2006;Vreshch & Chernega et al 2003;Vreshch & Lysenko et al 2004;Won & Clegg et al,2007;Zhang & Chen et al, 2006).…”

“…Among them, the N-containing bifunctional derivatives of β-diketones have been successfully applied to construct various metal-organic supramolecular complexes (Chen & Fronczek et al,2003;Chen & Fronczek et al,2004;Domasevitch & Vreshch, et al, 2006;Vreshch & Chernega et al 2003;Vreshch & Lysenko et al 2004;Won & Clegg et al,2007;Zhang & Chen et al, 2006). We report here on the structure of an interesting nonlinear N-containing bifunctional compound, 3-(pyridin-4-ylthio)pentane-2,4-dione, which is prepared according to the previously reported methord (Won & Clegg et al,2007).…”