The reactions of ferrocenyl cyclotetraphosphazenes with the N/N, N/O and N2O2 donor type bidentate and tetradentate ligands, and the investigation of their stereogenic, electrochemical and biological properties

In this study, 3-(N-ferrocenylmethylamino)-1-propanol, FcCH2N(CH2)3OH (1) was obtained by reducing with NaBH4 the Schiff base formed by ferrocenecarboxaldehyde and condensation reactions of 3-amino-1-propanol in methanol. Partially substituted mono-spiro (12) and 2,4-ansa (13), as a result of reactions of the sodium salt of bidentate ligand the NO donor atom with octachlorocyclotetraphosfazatetraene (tetramer, N4P4Cl8), in the presence of Et3N in THF medium in a ratio of 1:1 were synthesized. Partially and/or fully substituted cyclotetraphosphazene compounds (14-29) were prepared from the reactions of tetradentate aminopodans with N2O2 donor typed (2-4) and bidentate carbazolyl (5-8), and piperonal (9-11) substituted ligands with N/N and N/O donors with mono-spiro (12) and 2,4-ansa (13) using classical and microwave methods. The structures of the synthesized compounds (12-29) were determined using elemental analysis, mass spectrometry (ESI-MS), FTIR, 1H-, 13C- and 31P-NMR techniques. Spiro (except 12 and 18) and all ansa cyclotetraphosphazene compounds have more than one stereogenic P atom. Solid-state structures of compounds 16 and 27, suitable crystals of which can be obtained, were elucidated by X-ray diffraction method. These compounds have four different chiral P centers and the absolute configuration of stereogenic P-centers of an enantiomer is designated SS'S''R''' for 16 and RS'R'R'' for 27. Optical and electrochemical properties of some cyclotetraphosphazenes (15, 16, 18, 20 and 21) were investigated using UV-vis absorption and cyclic voltammetry (CV) techniques. As a result, these compounds can be suggested as ferrocene-based charge transformable phosphazene structures that can be used as new generation and synergistic dye-sensitized solar cell (DSSC) materials. In addition, antimicrobial activities of some partially and fully substituted derivatives (15, 16, 18 and 20-23) on various pathogenic bacteria and yeasts, their interactions with pBR322 plasmid DNA and MDA-MB-231 against breast cancer cells and COS-1 mammalian fibroblast cells. cytotoxic activities were investigated. Sep 2023, 327 pages Keywords: Phosphazenes, ferrocenyl cyclotetraphosphazenes, stereogenism, bioactivity, electrochemical properties