Morpholine- and Thiomorpholine-Based Amidodithiophosphonato Nickel Complexes: Synthesis, Characterization, P-N Cleavage, Antibacterial Activity and Silica Nano-Dispersion.

The reactivity of thiomorpholinium -(4-methoxyphenyl)--thiomorpholin-amidodithiophosphonate ( and morpholinium -(4-methoxyphenyl)--morpholin-amidodithiophosphonate towards nickel (II) dichloride hexahydrated is presented and the hydrolysis of the relevant metal complexes investigated. The hydrolytic products (S-MorH₂)₂ [Ni(dtp)₂]²- and (O-MorH₂)₂[Ni(dtp)₂]²- were characterized by means of FT-IR, H, and P NMR and XRD and the experimented P-N cleavage investigated and elucidated by means of DFT calculations. The antimicrobial activity of the neutral nickel complex was tested against a set of Gram-positive and Gram-negative bacteria alongside with its nanodispersion in a silica matrix. The complex [Ni(S-Mor-adtp)₂] did not show antibacterial activity, whilst the nano-dispersed sample demonstrated inhibition to growth of . The nanocomposites were fully characterized by means of XRPD, TGA, SEM and dinitrogen sorption techniques.