Ruthenium Complexes with Dithiophosphonates [Ar(RO)PS2]−and [Fc(RO)PS2]−(Ar =p-CH3OC6H4, Fc = Fe(η5-C5H4)(η5-C5H5))

Ferrocenyl Dithiophosphonate Ag(I) Complexes: Synthesis, Structures, Luminescence, and Electrocatalytic Water Splitting Tuned by Nuclearity and Ligands

The heterometallic [Ag(I)/Fe(II)] molecular electrocatalysts for hydrogen production were introduced here to recognize the mutual role of metallic nuclearity and ligand engineering. A series of ferrocenyl dithiophosphonate stabilized mononuclear [Ag(PPh3)2{S2PFc(OR)}] {where R=Me (1), Et (2), nPr (3), iPr (4), iAmyl (5); Fc=Fe (ɳ5-C5H4) (ɳ5-C5H5)} and dinuclear [Ag(PPh3){S2PFc(OR}]2 {where R=Et (2 a), and nPr (3 a)} complexes were synthesized and characterized by SCXRD, NMR (31P and 1H), ESI-MS, UV-Vis, and FT-IR spectroscopy. The comparative electrocatalytic HER behavior of 1-5 and 2 a-3 a showed effective current density of 1 mA/cm2 with overpotentials ranging from 772 to 991 mV, demonstrating the influence of extended and branched carbon chains in dithiophosphonates and metallic (mono-/di-) nuclearity, which correlates with documented tetra-nuclear [Ag4(S2PFc(OnPr)4], 6. DFT study suggests the coordinated (μ1-S) site of ligands is the reactivity center and the adsorption energy of intermediate [H*-SM] varies with the engineering of ligand and nuclearity. A catalytic mechanism using mononuclear (1) and di-nuclear (2 a) was proposed with the assistance of DFT. Each complex, being the first example of Ag(I) dithiophosphonates, exhibits intense photoluminescence with high quantum yields ranging from 33 % to 67 %. These results link the lower nuclearity structures to their physical and catalytic properties.

Reactions of Heterometallic Phosphinidene-Bridged MoMn and MoRe Complexes with Sulfur and Selenium: From Chalcogenophosphinidene- to Trithiophosphonate-Bridged Derivatives

Reactions of [MoReCp(μ-PR*)(CO)₆] with S₈ were strongly dependent on experimental conditions (R* = 2,4,6-C₆H₂^tBu₃). When using 1 equiv of sulfur, complex [MoReCp(μ-η²:κ¹_S-SPR*)(CO)₆] was slowly formed at 313 K, with a thiophosphinidene ligand unexpectedly bridging the dimetal center in the novel μ-κ¹_S:η² coordination mode, as opposed to the μ-κ¹_P:η² mode usually found in related complexes. The latter underwent fast decarbonylation at 363 K to give [MoReCp(μ-η²:η²-SPR*)(CO)₅], with a six-electron donor thiophosphinidene ligand rearranged into the rare μ-η²:η² coordination mode. Depending on reaction conditions, reactions with excess sulfur involved the addition of two or three S atoms to the phosphinidene ligand to give new complexes identified as the dithiophosphinidene-bridged complex [MoReCp(μ-η²:κ²_S,S'-S₂PR*)(CO)₅], its dithiophosphonite-bridged isomer [MoReCp(μ-κ²_S,S':κ²_S,S'-S₂PR*)(CO)₅], or the trithiophosphonate-bridged derivative [MoReCp(μ-κ²_S,S':κ²_S,S'-S₃PR*)(CO)₅], all of them displaying novel coordination modes of their PRS₂ and PRS₃ ligands, as determined by X-ray diffraction studies. In contrast, the related MoMn complex yielded [MoMnCp(μ-η²:η²-SPR*)(CO)₅] under most conditions. A similar output was obtained in reactions with gray selenium for either MoRe or MoMn phosphinidene complexes, which under different conditions only gave the pentacarbonyl complexes [MoMCp(μ-η²:η²-SePR*)(CO)₅] (M = Re, Mn), these providing a new coordination mode for selenophosphinidene ligands.

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

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.

Antibacterial Activity of Amidodithiophosphonato Nickel(II) Complexes: An Experimental and Theoretical Approach

The reactions of 2,4-bis(4-methoxyphenyl)-1,3-dithio-2,4-diphosphetane-2,4-disulfide (Lawesson's Reagent, LR) with benzylamine (BzNH2) and 4-phenylbutylamine (PhBuNH2) yield benzylammonium P-(4-methoxyphenyl)-N-benzyl-amidodithiophosphonate (BzNH3)(BzNH-adtp) and 4-phenylbutylammonium P-(4-methoxyphenyl)-N-(4-phenylbutyl)-amidodithiophosphonate (PhBuNH3)(PhBuNH-adtp). The relevant nickel complexes [Ni(BzNH-adtp)2] and [Ni(PhBuNH-adtp)2] and the corresponding hydrolysed derivatives (BzNH3)2[Ni(dtp)2] and (PhBuNH3)2[Ni(dtp)2] were prepared and fully characterized. The antimicrobial activity of the aforementioned amidodithiophosphonates against a set of Gram-positive and Gram-negative pathogen bacteria was evaluated, and [Ni(BzNH-adtp)2] and [Ni(PhBuNH-adtp)2] showed antiproliferative activity towards Staphylococcus aureus and Staphylococcus haemolyticus strains. density functional theory (DFT) calculations were performed to shed some light on the activity of reported compounds related to their tendency towards P-N bond cleavage.

Aqua-carbon-yl(ferrocenyldi-thio-phos-phon-ato-κ(2) S,S')bis-(tri-phenyl-phosphane-κP)ruthenium(II) dichloromethane mono-solvate

The structure of the title complex, [FeRu(C₅H₅)(C₅H₄OPS₂)(CO)(C₁₈H₁₅P)₂(H₂O)]·CH₂Cl₂, consists of one neutral [{FcP(O)S₂}Ru(CO)(H₂O)(PPh₃)₂] complex [Fc = Fe(η⁵-C₅H₄)(η⁵-C₅H₅)] and one CH₂Cl₂ solvent mol­ecule. The geometry around the Ru^II atom is pseudo-octa­hedral, with two cis-binding PPh₃ ligands and one chelating bidentate [Fc(O)PS₂]²⁻ ligand via two S atoms. The average Ru—S and Ru—P bond lengths are 2.434 (1) and 2.398 (1) Å, and the Ru—O and Ru—C bond lengths are 2.157 (3) and 1.826 (4) Å, respectively. In the crystal, pairs of O—H⋯O hydrogen bonds link adjacent mol­ecules into dimers.