Two acetylenedicarboxylato-bridged 4-styrylpyridine appended 1D coordination polymers: synthesis, structural characterization and variable temperature magnetism

Synthesis, crystal structure and magnetic properties of a one-dimensional Mn2+ complex constructed from (+)-dibenzoyltartaric acid and 2,2'-bipyridine

The self-assembly reaction of (+)-dibenzoyltartaric acid (D-H₂DBTA) with 2,2'-bipyridine (bpy) and Mn(CH₃CO₂)₂·4H₂O yielded a new coordination polymer, namely, catena-poly[[[diaqua(2,2'-bipyridine-κ²N,N')manganese(II)]-μ-2,3-bis(benzoyloxy)butanedioato-κ²O²:O³] dihydrate], {[Mn(C₁₈H₁₂O₈)(C₁₀H₈N₂)(H₂O)₂]·2H₂O}_n or {[Mn(DBTA)(bpy)(H₂O)₂]·2H₂O}_n, (I). Complex (I) has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA) and single-crystal and powder X-ray diffraction. It crystallizes in the orthorhombic space group P2₁2₁2₁. In the complex, the Mn²⁺ cation displays a distorted octahedral {MnO₄N₂} geometry, formed from two carboxylate O atoms of two DBTA^2- ligands, two cis-oriented N atoms from one chelating 2,2'-bipyridine ligand and two trans-oriented O atoms from coordinated water molecules. The polymer displays a 1D chain with an Mn...Mn distance of 9.428 (1) Å. Due to the presence of flexible polycarboxylate and rigid bipyridyl ligands in the molecular structure, a high thermal stability of the complex is attained. The magnetic properties of (I) were analyzed based on the mononuclear Mn²⁺ model due to the long intramolecular Mn...Mn distance. The zero field splitting (ZFS) contribution in the high-spin Mn²⁺ cation is almost negligible and there are weak antiferromagnetic couplings between 1D chains [zJ' = -0.062 (5) cm^-1], corresponding to an intermolecular Mn...Mn distance of 7.860 (2) Å.

Supramolecular assemblies involving biologically relevant antiparallel π-stacking and unconventional solvent driven structural topology in maleato and fumarato bridged Zn(ii) coordination polymers: antiproliferative evaluation and theoretical studies

In vitro anticancer activities have been explored in solvent driven maleato and fumarato bridged Zn(ii) coordination polymers involving energetically significant antiparallel π-stacking and enclathrated guest MeOH/H₂O moieties.

Cobaloximes as Building Blocks in Halogen-Bonded Cocrystals

In this work, we explore the halogen-bonded cocrystallization potential of cobaloxime complexes in the synthesis of cocrystals with perhalogenated benzenes. We demonstrate a strategy for synthesizing halogen-bonded metal–organic cocrystals by utilizing cobaloximes whose pendant bromide group and oxime oxygen enable halogen bonding. By combining three well-known halogen bond donor molecules differing in binding geometry and composition with three cobaloxime units, we obtained a total of four previously unreported cocrystals. Single crystal X-ray diffraction experiments showed that the majority of obtained cocrystals exhibited the formation of the targeted I···O and I···Br motives. These results illustrate the potential of cobaloximes as halogen bond acceptors and indicate that this type of halogen bond acceptors may offer a novel route to metal–organic halogen-bonded cocrystals.