Modulated Preparation and Structural Diversification of Zn^II and Cd^II Metal−Organic Frameworks with a Versatile Building Block 5-(4-Pyridyl)-1,3,4-oxadiazole-2-thiol

Abstract

Four novel Zn(II) and Cd(II) metal-organic coordination polymers with a versatile building block 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol (Hpyt) have been prepared under different conditions. [Zn3(pyt)4(OH)2]n (1) and [Cd(pyt)(HCOO)]n (3) were obtained through a solvothermal method, whereas {[Zn(pyt)2(H2O)(2)].(DMF)2}n (2) and {[Cd(pyt)2].CHCl3}n (4) were isolated under general conditions. X-ray single-crystal diffraction indicates that the anionic ligand pyt adopts a thioamide isomer in 1, 2, and 4, but a thiolate form in 3. Four types of binding modes involving monodentate (eta-N(oxa)), bidentate (mu-N(py),N(oxa), or mu-N(py),S,S) and tridentate (mu-N(py),N(oxa),S) are observed. The discrepancy of the synthetic routes and metal-coordination preferences facilitates the production of the final crystalline materials with distinct network structures, including a 1D zigzag array of 1 with dangling arms, a common 2D (4,4) coordination layer of 2, a decorated 3D alpha-Po network of 3, and an unprecedented (3,6)-connected 3D framework of 4 with a (4(2).6)2(4(2).6(2).8(7).10(2)) topology. Notably, the hydrolysis of DMF solvates leads to the formation of formate ions, being a component in the structure of 3. Complexes 2 and 4 show 1D channels in which the solvates are accommodated, and even after the exclusion of these guests, the porous host frameworks are still retained. Thermal stability and gas adsorption properties have also been studied.

Two manganese(II) complexes based on anthracene-9-carboxylate: Syntheses, crystal structures, and magnetic properties

“…In general, the IR spectra show features attributable to each component of the complexes [35], and the characteristic bands of carboxylate groups appeared in the usual region at 1597-1549 cm -1 for the antisymmetric stretching vibrations and at 1442-1392 cm -1 for the symmetric stretching vibrations. Furthermore, the Dm values [Dm = m as (COO -) -m s (COO -)] are 157 and 122 cm -1 for (1) as well as 171 and 154 cm -1 for (2), respectively, in good agreement with their solid structural features from the results of crystal structures [36,37]. The elemental analyses of (1) and (2) are also consistent with the results of the structural analysis.…”

Powerful Antibacterial Activity of Phenyl‐Thiolatobismuth(III) Complexes Derived from Oxadiazolethiones

“…As an example, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione results in thiolates with Hg and Cd, [20] and thioamides with Ni, [21] Cu, [21] Zn, [21] and Mn. [22,23] A search of the Cambridge Crystallographic Database [24] shows a similar trend is observed with analogous ligands 5-(R)-1,3,4-oxadiazole-2-thione, where R = pMeOPh and 2-Pyr. For ligands in which R = 2-thienyl, 2-furyl, o-MeOPh and m-Pyr, only complexes of the lighter metals (Cu, Ni, Mn) have been structurally authenticated.…”

“…[18] Complexes are known with most of the d-block metals, [19] though only a few have been crystallographically characterised. The heavier metals generally favour direct S-M bonding giving rise to thiolates, while the lighter metals favour N-M bonding and the formation of thioamides.…”

Polycyclic aromatic hydrocarbons from asphalt binder: extraction and characterization

“…The HPYT molecule is a rigid ligand that has been employed as a surface modifier for the electrochemistry of proteins and in coordination chemistry. 5,12 The structure of HPYT on the gold surface has been characterized by STM previously. 5 The molecule forms a slightly distorted √3x√3 R30° lattice and the molecular structure has some defects such as a few clusters and pits on the surface.…”