Browsing by Author "Albold, Uta"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Precursor molecules for 1,2-diamidobenzene containing cobalt(ii), nickel(ii) and zinc(ii) complexes : synthesis and magnetic properties
    (2024) Hunger, David; Suhr, Simon; Bayer, Valentin; Albold, Uta; Frey, Wolfgang; Sarkar, Biprajit; Slageren, Joris van
    Molecular magnetic materials based on 1,2-diamidobenzenes are well known and have been intensively studied both experimentally and computationally. They possess interesting magnetic properties as well as redox activity. In this work, we present the synthesis and investigation of potent synthons for constructing discrete metal-organic architectures featuring 1,2-diamidobenzene-coordinated metal centres. The synthons feature weakly bound dimethoxyethane (dme) ligands in addition to the 1,2-diamidobenzene. We characterize these complexes and investigate their magnetic properties by means of static and dynamic magnetometry and high-field electron paramagnetic resonance (HFEPR). Interestingly, the magnetic and magnetic resonance data strongly suggest a dimeric formulation of these complexes, viz. [MII(bmsab)(dme)]2 (bmsab = 1,2-bis(methanesulfonamido)benzene; dme = dimethoxyethane) with M = Co, Ni, Zn. A large negative D-value of -60 cm-1 was found for the Co(ii) synthon and an equally large negative D of -50 cm-1 for the Ni(ii) synthon. For Co(ii), the sign of the D-value is the same as that found for the known bis-diamidobenzene complexes of this ion. In contrast, the negative D-value for the Ni(ii) complex is unexpected, which we explain in terms of a change in coordination number. The heteroleptic Co(ii) complex presented here does not feature slow relaxation of the magnetization, in contrast to the homoleptic Co(ii) 1,2-diamidobenzene complex.
  • Thumbnail Image
    ItemOpen Access
    Synthesis, characterization, and evaluation of antibacterial activity of ferrocenyl‐1,2,3‐triazoles, triazolium salts, and triazolylidene complexes of gold(i) and silver(i)
    (2021) Hoyer, Carolin; Schwerk, Peter; Suntrup, Lisa; Beerhues, Julia; Nössler, Maite; Albold, Uta; Dernedde, Jens; Tedin, Karsten; Sarkar, Biprajit
    1,2,3‐triazoles, the corresponding triazolium salts, and the resulting mesoionic carbenes (MICs) of the 1,2,3‐triazol‐5‐ylidene type are at the forefront of contemporary research. In this contribution, we present a comprehensive study involving eight triazoles, seventeen triazolium salts, two silver(i)‐ and four gold(i)‐MIC complexes. The substituents on the N1‐atom of the heterocycles are either ferrocenyl or phenyl and those on the C4‐atom bear various alkyl groups. All the compounds were thoroughly characterized by a combination of multinuclear NMR spectroscopy, ESI‐MS and in many cases through single crystal X‐ray diffraction studies. In the electrochemical analysis, all ferrocenyl‐containing compounds display a ferrocenyl‐based oxidation step. Additionally, in both the triazolium salts, and the respective metal complexes, a ligand centered reduction step is observed. All the complexes were tested for their antibacterial properties against the Gram‐negative bacterial strains Salmonella typhimurium (S. typhimurium) and Escherichia coli (E. coli). Many of the tested compounds display good antibacterial activity against the rather resistant Salmonella strain. To inhibit the growth of E. coli, higher concentrations of the compounds tested were required. A preliminary structure‐activity relationship of this set of compounds is also reported.