Summary: | Paracetamol (acetaminophen) is a common painkiller and antipyretic drug used globally. Attachment of paracetamol to a series of organoiron dendrimers was successfully synthesized. The aim of this study is to combine the benefits of the presence of these redox-active organoiron dendrimers, their antimicrobial activities against some human pathogenic Gram-positive, and the therapeutic characteristics of paracetamol. The antimicrobial activity of these dendrimers was investigated and tested with a minimum inhibitory concentration and this has been reported. Some of these newly synthesized dendrimers exhibited the highest inhibitory activity against methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), vancomycin-resistant <i>Enterococcus faecium</i> (VRE), and <i>Staphylococcus warneri</i> compared to reference drugs. The results of this study indicate that the antimicrobial efficacy of the dendrimers is dependent on the size of the redox-active organoiron dendrimer and its terminal functionalities. The best result has been recorded for the fourth-generation dendrimer <b>11</b>, which attached to 48 paracetamol end groups and has 90 units composed of the η<sup>6</sup>-aryl-η<sup>5</sup>-cyclopentadienyliron (II) complex. This dendrimer presented inhibition of 50% of the growth (IC<sub>50</sub>) of 0.52 μM for MRSA, 1.02 μM for VRE, and 0.73 μM for <i>Staphylococcus warneri.</i> The structures of the dendrimers were characterized by elemental analysis, Fourier transform infrared (FT-IR), nuclear magnetic resonance (<sup>1</sup>H-NMR), and <sup>13</sup>C-NMR spectroscopic techniques. In addition, all synthesized dendrimers displayed good thermal stability in the range of 300–350 °C following the degradation of the cationic iron moieties which occurred around 200 °C.
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