Polyaromatic Carboxylate Ligands Based Zn(II) Coordination Polymers for Ultrasound-Assisted One-Pot Tandem Deacetalization–Knoevenagel Reactions

Solvothermal reactions between the polyaromatic group containing carboxylic acid pro-ligands 5-{(pyren-1-ylmethyl)amino}isophthalic (H2L1) and 5-{(anthracen-9-ylmethyl)amino}isophthalic (H2L2) with Zn(NO3)2·6H2O led to formation of new 1D coordination polymer [Zn(L1)(NMF)]n (1) four other polymers, [Zn(L1)(DMF)]n (2), [Zn(L1)(4,4′-Bipy)]n (3), [Zn(L2)(DMF)(H2O)2]n·n(H2O) (4) [Zn2(L2)2(DMF)(CH3OH)]n (5), which were previously reported by our group. Single crystal X-ray diffraction analyses revealed that CP 1 has a one-dimensional (1D) double-chain-type structure similar 2. For 3, assembly Zn(II) ion deprotonated L12− ligand 4,4′-bipyridine produces 3D network. 4 5 exhibit linear 2D layered-type structures. The ultrasound-assisted tandem promoted CPs have not yet been well studied. Thus, in present work, we investigated catalytic activities newly synthesized 1, as 2–5, towards deacetalization–Knoevenagel condensation various acetals under ultrasonic irradiation. They proved be highly efficient, special emphasis on catalyst completely converted substrate (benzaldehyde dimethyl acetal) into desired product (2-benzylidenemalononitrile) after 2 h. stability catalysts, namely regarding action radiation, was demonstrated their reuse, where only slight loss activity observed cycles. Heterogeneity also demonstrated, no leaching detected over