Syntheses, Structures, and Antimicrobial Activity of New Remarkably Light-Stable and Water-Soluble Tris(pyrazolyl)methanesulfonate Silver(I) Derivatives of <i>N</i>‑Methyl-1,3,5-triaza-7-phosphaadamantane Salt - [mPTA]BF₄

Abstract

Two new silver­(I) complexes of formula [Ag­(mPTA)₄]­(Tpms)₄(BF₄) (<b>1</b>) and [Ag­(Tpms)­(mPTA)]­(BF₄) (<b>2</b>) (mPTA = <i>N</i>-methyl-1,3,5-triaza-7-phospha­adamantane cation, Tpms = tris­(pyrazol-1-yl)­methane­sulfonate anion) have been synthesized and fully characterized by elemental analyses, ¹H and ³¹P­{¹H} NMR, ESI-MS, and IR spectroscopic techniques. The single-crystal X-ray diffraction study of <b>1</b> discloses a noncoordinated nature of the Tpms species, existing as counterions around the highly charged metal center [Ag­(mPTA)]⁵⁺, <b>1</b> being the first reported coordination compound bearing a κ⁰-Tpms. <b>1</b> features high solubility and stability in water (<i>S</i>_25 °C ≈ 30 mg·mL^–1). The two complexes interact with calf thymus DNA via intercalation mode, binding to the BSA with decrease of its tryptophan fluorescence with a static quenching mechanism. The two new silver complexes exhibit significant antibacterial and antifungal activities screened <i>in vitro</i> against the standard strains of <i>Staphylococcus aureus</i>, <i>Enterococcus faecalis</i>, <i>Pseudomonas aeruginosa</i>, <i>Escherichia coli</i>, and <i>Candida albicans</i>