A large polymolybdate-templated {Ag49Mo16} cluster protected by six thiacalix[4]arene (TC4A) molecules was synthesized by a one-pot solvothermal reaction. Structural analysis shows that the {Ag49Mo16} is assembled by inserting a [Mo6O22]8-...

This study used the tert-butylcalix­[6]­arene (TBC­[6]) as the ligand and successfully synthesized six TBC[6]-stabilized titanium-oxo clusters (TOCs) by the one-step solvothermal reaction. These six compounds were [Ti4O2(TBC­[6])2] (Ti 4 ), {Ti2(TBC­[6])­(EtO)2(SaH2)2} (Ti 2 -SA, H2Sa = squaric acid), {Ti2(TBC­[6])2(EtO)2(Oa)} (Ti 2 -OA, H2Oa = oxalic acid), [H2Ti4(TBC­[6])­(BA)2(EtO)10] (Ti 4 -BA, HBA = benzoic acid), [Ti6O2(TBC­[6])­(BA)4(OiPr)10] (Ti 6 -BA), and [Ti8(TBC­[6])2(Sal)4(EtO)16] (Ti 8 -Sal, H2Sal = salicylic acid). These clusters contain one or two TBC[6] ligands, with the biconical or monoconical configuration, greatly increasing the variety of TOCs it could support. The introduction of auxiliary carboxylic ligands can further stimulate the growth of structures, with the cluster core gradually increased from {Ti-TBC[6]-Ti} to {Ti2-TBC­[6]-Ti2}, to {Ti3-TBC­[6]-Ti3}, and finally to {Ti3-TBC­[6]-Ti2-TBC­[6]-Ti3} with 3.1 nm length. Structural regulation may affect their solution stability, absorption spectra, and photocurrent response. The study of catalytic activities shows that these clusters can be used as recyclable heterogeneous photocatalysts for the oxidation of sulfide to sulfoxide. The catalytic efficiency of the TBC[6]-Ti x system is closely related to the cluster structure, and the exposure of the Ti site on the catalyst surface can significantly enhance the catalytic activity of the clusters.

In this study, Pd based on 2-Aminopyrimidine and 1H-benzo[d]imidazol-2-amine functionalized Fe 3 O 4 magnetic nanoparticles [(Pd-APM-PSi-Fe 3 O 4) and (Pd-BIA-PSi-Fe 3 O 4)] was designed and used for the synthesis of di aryl ether by Ulmann cross-coupling reactions. Ulmann reaction performed with mixing of the arylhalides and phenol derivatives in DMF solvent. The prepared catalysts were characterized with various analytical techniques such as FT-IR, XRD, TGA, SEM, TEM, EDX, ICP and VSM. Pd-APM-PSi-Fe 3 O 4 and Pd-BIA-PSi-Fe 3 O 4 catalysts demonstrated good to excellent yields catalytic efficiency for Ulmann reactions in comparison with to commercial palladium catalysts. The catalyst is easily recycled and reused without loss of the catalytic activity. The combined merits of reusable catalyst conditions make the condensation with safe operation, no leaching of pd into environment, low pollution, rapid access to products and simple workup. Also, these novel magnetic nanocatalysts are superior to the industry standard Pd in every relevant aspect. They feature a way higher initial activity, a much more convenient separation, better recycling, and less contamination of the products. Last but not least, they can be very easily prepared from commercially available Fe 3 O 4 nanoparticles using standard laboratory equipment.