Hydrophobic/Hydrophilic Interplay in 1,2,4-Triazole- or Carboxylate-Based Molybdenum(VI) Oxide Hybrids: A Step Toward Development of Reaction-Induced Self-Separating Catalysts

authors	Lysenko, AB; Senchyk, GA; Domasevitch, KV; Neves, P; Valente, AA; Pillinger, M; Goncalves, IS
nationality	International
journal	CHEMCATCHEM
author keywords	homogeneous catalysis; epoxidation; N ligands; carboxylate ligands; hydrothermal synthesis; transition metals
keywords	STRUCTURAL ELUCIDATION; OLEFIN EPOXIDATION; OXIDATION; COMPLEXES; BEHAVIOR
abstract	2-(4H-1,2,4-triazol-4-yl)acetic acid (trglyH) and (dl)-4-methyl-2-(4H-1,2,4-triazol-4-yl)pentanoic acid (trleuH) were used as ligands for the development of MoO3 coordination hybrids for catalytic applications. Coordination polymers [Mo2O6(Htrgly)] . H2O (1) and [MoO3(trleuH)] . 0.5H(2)O (2) were prepared and structurally characterized. Compound 1 adopts a structure in which edge-sharing MoO6 octahedra are organized in a ribbon motif via mu(3)-O bridges. The Htrgly ligand exists as a zwitterion: -CO2- links two Mo-VI in a mu(2)-eta(1) : eta(1) mode, while positively charged triazolium is left uncoordinated. In 2, Mo atoms are joined in a chain through mu(2)-O. The more hydrophobic trleuH appears in a nonionized form and its [N-N] sites serve as a clamp for supporting the [-OMo(O)(2)-OMo(O)(2)(tr)(2)](n) sequence. The complexes were explored for liquid phase catalytic epoxidation of cis-cyclooctene, using H2O2 or tert-butylhydroperoxide as oxidants. The hybrids showed good catalytic activity, and 2 behaved as a reaction-induced self-separating catalyst for olefin epoxidation with H2O2, presenting advantages of homogeneous and heterogeneous catalysis.
publisher	WILEY-V C H VERLAG GMBH
issn	1867-3880
isbn	1867-3899
year published	2021
volume	13
issue	13
beginning page	3090
ending page	3098
digital object identifier (doi)	10.1002/cctc.202100389
web of science category	9
subject category	Chemistry, Physical
unique article identifier	WOS:000652284800001