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 (H-1, C-13 and P-31) spectroscopy and X-ray crystal structure determination. The crystal structure of new complex [Ag(mu-dppf)(NO3)](2)center dot 4CHCl(3) 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(mu-dppf)(NO3)](2)center dot 4CHCl(3) clearly shows the formation of a supramolecular network through C-HMIDLINE HORIZONTAL ELLIPSISX (X = N, O, Cl) hydrogen bond interactions in which the asymmetric unit contains two independent molecules of [Ag(mu-dppf)(NO3)](2)center dot 4CHCl(3). Both independent molecules related by inversion to form the dimeric silver complex with AgMIDLINE HORIZONTAL ELLIPSISAg distances of 4.000 and 4.0235 angstrom. 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 pi-pi* 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.

Automated summary

In this study, a supramolecular dimeric silver complex was prepared and characterized. The crystal structure of the complex showed specific coordination geometry and formation of a supramolecular network through hydrogen bond interactions. The luminescence properties in different solvents and cytotoxic effects against cancer cell lines were also investigated.