Supramolecular Dimeric Silver(I) Complex Based on the 1,1′-Bis(diphenylphosphino)ferrocene: Thermal Behaviors, Luminescence Studies and Cytotoxic Properties.

A supramolecular dimeric complex [Ag(dppf)(NO₃)]₂ was prepared via the reaction of a solution of AgNO₃ in methanol/dichloromethane with 1,1′-bis(diphenylphosphino)ferrocene (dppf) which was fully characterized by IR, elemental analysis, multinuclear NMR (¹H, ¹³C and ³¹P) spectroscopy and X-ray crystal structure determination. The crystal structure of new complex [Ag(μ-dppf)(NO₃)]₂⋅4CHCl₃ reveals that the coordination geometry about each Ag(I) center in the dimeric complex is 4 + 1 polyhedron. As well, the crystal packing of complex [Ag(μ-dppf)(NO₃)]₂⋅4CHCl₃ clearly shows the formation of a supramolecular network through C–H⋯X (X = N, O, Cl) hydrogen bond interactions in which the asymmetric unit contains two independent molecules of [Ag(μ-dppf)(NO₃)]₂⋅4CHCl₃. Both independent molecules related by inversion to form the dimeric silver complex with Ag⋯Ag distances of 4.000 and 4.0235 Å. Hirshfeld surface analysis of the structure as well as its fingerprints were used to identify and quantify the inter–molecular interactions of hydrogen bonds. Luminescence properties of the supramolecular silver complex were assigned to π–π* transitions in different solvents. Thermal properties of this complex showed a three-step decomposition. The cytotoxic properties of this complex were also studied using MTT assays against MCF-7 human breast cancer, U87-MG human glioblastoma, HT-29 human colorectal cancer, and SCOV-3 human ovarian cancer cell lines in comparison with AGO1522 human normal skin fibroblast cell line. The supramolecular silver complex exhibited higher cytotoxic effects (lower IC₅₀) against U87-MG, MCF-7, HT-29 and SCOV-3 cancer cell lines in comparison with AGO1522. [ABSTRACT FROM AUTHOR]