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

Podda, Enrico

Member of the Collaboration Group

;Carla Aragoni, M

Member of the Collaboration Group

;Arca, Massimiliano

Member of the Collaboration Group

;Atzeni, Giulia

Member of the Collaboration Group

;Coles, Simon J

Member of the Collaboration Group

;Ennas, Guido

Member of the Collaboration Group

;Isaia, Francesco

Member of the Collaboration Group

;Lippolis, Vito

Member of the Collaboration Group

;Orru, Germano

Member of the Collaboration Group

;Scano, Alessandra

Member of the Collaboration Group

;Orton, James B

Member of the Collaboration Group

;Pintus, Anna

Member of the Collaboration Group

;Scano, Alessandra

Member of the Collaboration Group

2021-01-01

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Abstract

The reactivity of thiomorpholinium P-(4-methoxyphenyl)-N-thiomorpholin-amidodithiophosphonate (S-MorH+₂)(S-Mor-adtp-) and morpholinium P-(4-methoxyphenyl)-N-morpholin-amidodithiophosphonate (O-MorH+₂)(O-Mor-adtp-) towards nickel (II) dichloride hexahydrated is presented and the hydrolysis of the relevant metal complexes investigated. The hydrolytic products (S-MorH+₂)₂ [Ni(dtp)₂]²- and (O-MorH+₂)₂[Ni(dtp)₂]²- were characterized by means of FT-IR, 1H, and 31P 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 [Ni(S-Mor-adtp)₂] 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 [Ni(S-Mor-adtp)₂]_SiO₂ demonstrated inhibition to growth of Staphylococcus aureus. The nanocomposites were fully characterized by means of XRPD, TGA, SEM and dinitrogen sorption techniques.