447441-86-3Relevant academic research and scientific papers
Solvent-free mechanochemical synthesis of dithiophosphonic acids and corresponding nickel(II) complexes
Ajayi, Tomilola J.,Pillay, Michael N.,van Zyl, Werner E.
, p. 1205 - 1211 (2017)
We report a green chemistry route for dithiophosphonic acids of the type [HS2P(OR)(4-MeOC6H4)] [R = H, (1); Me (2); Et (3); iPr (4)]. The different dithiophosphonic acids formed through the stoichiometric addition of water or alcohols to Lawesson’s Reagent (molar ratio 2:1), followed by an intimate grinding of themixture (mechanochemistry). The products formed without the use of solvent or external heat in less than 5 minutes. The acids are formed with 100% atomeconomy, and because they form in essentially quantitative yield, are also formed with >98% atom efficiency and an E-factor = 0, because no waste is produced. Of importance is that this methodology is different from conventional methods in forming dithiophosphonic acids where the use of organic solvents, added heat, long reaction times and lower yields are commonplace. We further demonstrate that nickel(II) complexes can form directly from the in situ generated acids. Thus, the reaction between 1–4 and NiCl2 · 6 H2O (molar ratio 2:1) lead to complexes of the type [Ni{S2P(OR) (4-MeOC6H4)}2] [R = H, (5);Me (6); Et (7); iPr (8)] with no use of organic solvent. All compounds were characterized or verified by a combination of 1H, 31P NMR, elemental analysis (solids), and FT-IR.
Triphenylphosphine-Assisted Transformation of NiS to Ni2P through a Solvent-Less Pyrolysis Route: Synthesis and Electrocatalytic Performance
Ayom, Gwaza E.,Choi, Jonghyun,Gupta, Ram K.,Khan, Malik D.,Revaprasadu, Neerish,Shombe, Ginena B.,Van Zyl, Werner E.
supporting information, p. 11374 - 11384 (2021/07/31)
Straightforward synthetic routes to the preparation of transition metal phosphides or their chalcogenide analogues are highly desired due to their widespread applications, including catalysis. We report a facile and simple route for the preparation of a pure phase nickel phosphide (Ni2P) and phase transformations in the nickel sulfide (NiS) system through a solvent-less synthetic protocol. Decomposition of different sulfur-based complexes (dithiocarbamate, xanthate, and dithiophosphonate) of nickel(II) was investigated in the presence and absence of triphenylphosphine (TPP). The optimization of reaction parameters (nature of precursor, ratio of TPP, temperature, and time) indicated that phosphorus- and sulfur-containing inorganic dithiophosphonate complexes and TPP (1:1 mole ratio) produced pure nickel phosphide, whereas different phases of nickel sulfide were obtained from dithiocarbamate and xanthate precursors in the presence or absence of TPP. A plausible explanation of the sulfide or phosphide phase formation is suggested, and the performance of Ni2P was investigated as an electrocatalyst for supercapacitance and overall water-splitting reactions. The performance of Ni2P with the surface free of any capping agents is not well explored, as common synthetic methods are solution-based routes; therefore, the electrocatalytic performance was also compared with metal phosphides, prepared by other routes. The highest specific capacitance of 367 F/g was observed at 1 A/g, and the maximum energy and power density of Ni2P were calculated to be 17.9 Wh/kg and 6951 W/kg, respectively. The prepared nickel phosphide required overpotentials of 174 and 316 mV along with Tafel slopes of 115 and 95 mV/dec to achieve a current density of 10 mA/cm2 for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively.
