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Seven new bis(μ-oxo)dimanganese complexes with Mn2(III , III) or Mn2(III , IV) oxidation states were prepared using quinoline- and isoquinoline-based tetraamine ligands. The structures of the ligands include ethylenediamine, trans-1,2-cyclohexanediamine and tripodal amine, bearing two or three nitrogen-containing heteroaromatics. Regardless of the skeleton and number of aliphatic nitrogen atoms in the ligands, quinoline complexes stabilize the Mn2(III , III) oxidation state, whereas, isoquinoline ligands afford Mn2(III , IV) complexes. A systematic comparison of the differences in structural parameters and redox potentials of a total of 14 complexes with a (μ-O)2Mn2 diamond core, which includes corresponding pyridine and quinoxaline derivatives as supporting ligands, highlights the distinct deviation of quinoline and tripodal amine motifs in this ligand series. [ABSTRACT FROM AUTHOR]

Iron oxide-based nanoparticles (NP) were covalently modified with sinapic acid (SA) through a condensation reaction to assist the ionization of both large and small molecules. The morphology of SA-modified NPs (SA-NP) was characterized by transmission electron microscopy (TEM), and the modification of the NP surface with SA was confirmed using ultraviolet (UV) and infrared (IR) spectroscopy. The number of SA molecules was estimated to be 6 per NP. SA-NP-assisted laser desorption/ionization was carried out on small molecules, such as pesticides and plant hormones, and large molecules, such as peptides and proteins. A peptide fragment from degraded proteins was detected more efficiently compared with conventional methods. [ABSTRACT FROM AUTHOR]