A 3D 2-fold interpenetrating Cu(II) coordination polymer based on 4,4′-oxybis(benzoic acid) and 1,3-bis(2-methyl-imidazol-1-yl) benzene exhibiting photocatalytic properties

A new Cu(II) complex, [Cu2(1,3-BMIB)(OBA)2] n (1) (1,3-BMIB = 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene, H2OBA = 4,4′-oxybis(benzoic acid)) was hydrothermally synthesized and has been structurally characterized. Complex 1 possesses a 3D 2-fold interpenetrating framework based on [Cu(OBA)] n layers with a Schläfli symbol {412.63}. Complex 1 displays excellent photocatalytic properties in the degradation of methylene blue (MB) and rhodamine B (RhB).

Zn/Ni and Zn/Pd Heterobimetallic Coordination Polymers with [SSC-N(CH2COO)2]3− Ligands

In the construction of heterobimetallic coordination polymers based on dithiocarbamato–carboxylate (DTCC ligands), platinum as a thiophilic metal center can be replaced by the cheaper nickel or palladium. The compounds Zn[Pd(HL)2] and Zn2[M(L)2] (M = Ni, Pd; L = {SSC-N(CH2COO)2}3−) were prepared in a sequential approach starting from K3(L). The products were characterized by IR and NMR spectroscopy, thermal analyses, and single-crystal X-ray diffraction. The products decompose under nitrogen between 300 and 400 °C. Zn[Pd(HL)2] · 6H2O forms polymeric chains in the solid state, and the Zn2[M(L)2] · 14H2O (M = Ni, Pd) exhibit two-dimensional polymeric structures, each being isotypic with the respective Zn/Pt analogs. While the carboxylate groups in all these products are coordinated to zinc in a κO-monodentate mode, a structural variant of Zn2[Ni(L)2] having κO:κO′-briding carboxylate groups was also obtained. Exchange of the metal sites in the two Ni/Zn compounds was not observed, and these compounds are therefore diamagnetic.

Solvent-mediated structural transformations of copper(II) coordination polymers induced by different short-chain alcohols

A three-dimensional copper(II) coordination polymer (CP), {Cu(L-F)(N₃)}_n (1), was synthesized by reacting Cu(NO₃)₂ with 5-fluoronicotinic acid (HL-F) and NaN₃ in a water medium. Complex (1) shows a 3D network, in which the 1D [Cu₂(COO)N₃]_n chains are interconnected via L-F ligands. By immersing (1) into different short-chain alcohols (CH₃OH, C₂H₅OH and HOC₂H₄OH), three different CPs were isolated, including {Cu₃(L-F)₄(N₃)₂(CH₃OH)₂}_n (2), {Cu₃(L-F)₄(N₃)₂(C₂H₅OH)₂}_n (3) and {Cu_2.5(L-F)₃(N₃)₂(HOC₂H₄OH)_0.5}_n (4). CPs (2) and (3) display a similar structure, in which trinuclear subunit [Cu₃(COO)₂(N₃)₂(solvent)₂] is generated. Furthermore, such entities are interconnected via L-F ligands to give rise to a 3D network. As for (4), there are trinuclear [Cu₃(COO)₂(N₃)₂] and binuclear [Cu₂(COO)N₃] units, which are interconnected by L-F ligands to generate a 3D network. Notably, in (2) and (3), the coordination modes of CH₃OH and C₂H₅OH solvents are monodentate; whereas for (4), the HOC₂H₄OH solvent adopts a bridging mode to link two Cu atoms. Of further interest, these processes are solvent-mediated structural transformations, with obvious colour changes in the crystals. Structural changes and mechanisms of transformation are discussed in detail.

Influence of ionic liquids on the syntheses and structures of Mn(ii) coordination polymers based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands

[RMI]Br probably serves as a template directing agent for the formation of a cluster helicate in 2, while it serves as a mineralizing agent in 3–6. Additionally, [RMI]Br could obviously improve the crystal yield of 7.