Synthesis, characterization, and structures of mononuclear and phenoxo-/acetato-bridged trinuclear zinc(II) complexes from salan ligands: Study of their hydrolytic activity

• Published in: Journal of molecular structure 2024-07, Vol.1308, p.138106, Article 138106
• Main Authors: Dinda, Rupam, Mohanty, Monalisa, Wilson, Liam, Roy, Satabdi, Mohapatra, Deepika, Patra, Sushree Aradhana, Schenk, Gerhard, Pessoa, João Costa, Sasamori, Takahiro, Aurelien, Crochet
• Format: Article
• Language: English
• Subjects: Phosphoesterase activity; Salan; X-ray crystal structure; Zinc(II) complexes
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2024.138106

•Synthesis of novel mono- and trinuclear Zinc(II) complexes of salan ligands.•Investigation of their in vitro phosphatase activity.•Complex 3 showed considerable catalytic activity. Synthesis of one mononuclear [ZnL1] (1) and two trinuclear phenoxo-/acetato-bridged zinc(II) complexes [Zn3Cl2(L2)2] (2) and [Zn3(OAc)2(L1)2] (3) containing tetradentate diaminobis(phenolato) “salan” ligands are reported. The ligand precursors and their corresponding zinc complexes are characterized by elemental analysis, NMR, IR, and UV–vis spectroscopy. Molecular structures of complexes 2 and 3 are solved by single-crystal X-ray crystallography, while the fate of the complexes in solution is assessed by ESI-MS spectrometry analysis. All complexes (1–3) were studied for their phosphoesterase activity by using para-nitrophenyl phosphate (PNPP) and bis(2,4–dinitrophenyl) phosphate (BNPP) as substrates. While complex 1 has no activity for these substrates, complex 3 effectively hydrolyses PNPP (1.6 × 10−3 s−1), and complex 2, which is less reactive than 3, displays comparable activities towards both substrates (2.0 × 10−4 s−1 and 5.4 × 10−4 s−1, respectively). The importance of evaluating the speciation of Zn-species present for the understanding of the mechanism of the phosphoesterase reaction is discussed. Synthesis and structural investigation of mononuclear and phenoxo/aceto bridged trinuclear zinc(II) complexes and their phosphoesterase activity. [Display omitted]