Synthesis, spectroscopic and structural properties of an unusual series of homoleptic phosphine oxide complexes of the alkaline earth dications

Open-Ended Metallodithiolene Complexes with the 1,2,4,5-Tetrakis(diphenylphosphino)benzene Ligand: Modular Building Elements for the Synthesis of Multimetal Complexes

Open-ended, singly metalated dithiolene complexes with 1,2,4,5-tetrakis(diphenylphosphino)benzene (tpbz) are prepared either by ligand transfer to [Cl₂M(tpbz)] from (R₂C₂S₂)SnR′₂ (R = CN, R′ = Me; R = Me, R′ = ⁿBu) or by a direct reaction between tpbz and [M(S₂C₂R₂)₂] (M = Ni, Pd, Pt; R = Ph, p-anisyl) in a 1:1 ratio. The formation of dimetallic [(R₂C₂S₂)M(tpbz)M(S₂C₂R₂)] attends these syntheses in modest amounts, but the open-ended compounds are readily separated by silica chromatography. As affirmed by X-ray crystallographic characterization of numerous members of the set, the [(R₂C₂S₂)M(tpbz)] compounds show dithiolene ligands in their fully reduced ene-1,2-dithiolate form conjoined with divalent Group 10 ions. Minor amounts of octahedral [(Ph₂C₂S₂)₂Pt^IV(tpbz)], a presumed intermediate, are isolated from the preparation of [(Ph₂C₂S₂)Pt^II(tpbz)]. Heterodimetallic [(Ph₂C₂S₂)Pt(tpbz)Ni(S₂C₂Me₂)] is prepared from [(Ph₂C₂S₂)Pt^II(tpbz)]; its cyclic voltammogram, upon anodic scanning, shows two pairs of closely spaced, but resolved, 1e^– oxidations corresponding first to [R₂C₂S₂^2–] – 1e^– → [R₂C₂S^•S^–] and then to [R₂C₂S^•S^–] – 1e^– → [R₂(C=S)₂]. The open diphosphine of [(R₂C₂S₂)M(tpbz)] can be oxidized to afford open-ended [(R₂C₂S₂)M(tpbzE₂)] (E = O, S). Synthesis of the octahedral [(dppbO₂)₃Ni][I₃]₂ [dppbO₂ = 1,2-bis(diphenylphosphoryl)benzene] suggests that the steric profile of [(R₂C₂S₂)M(tpbzE₂)] is moderated enough that three could be accommodated as ligands around a metal ion.

Open-ended metallodithiolene complexes with 1,2,4,5-tetrakis(diphenylphosphino)benzene (tpbz) are prepared either by the reaction of [M(S₂C₂R₂)₂] with tpbz in a 1:1 ratio or by transmetalation from [(R₂C₂S₂)SnR′₂] to [Cl₂M(tpbz)]. ³¹P NMR spectroscopy provides a clear diagnostic with the metalated (∼55 ppm) and open-phosphine (−14 ppm) signals. These compounds may be metalated at their open end to produce heterodimetallic compounds, or the open phosphines may be oxidized with chalcogen donors to the corresponding phosphine oxides or sulfides.

Crystal structure of aqua-tris-{μ-N-[bis(diethyl-amino)phosphoryl]-2,2,2-tri-chloroacetamidato-κ3O,O':O}calciumsodium

In the mol-ecular structure of the title compound, [CaNa(C10H20Cl3N3O2P)3(H2O)], the Ca2+ ion has a slightly distorted octa-hedral coordination environment defined by six O atoms which belong to the carbonyl and phosphoryl groups of the three coordinating ligands. Two Cl atoms of CCl3 groups and four O atoms form the coordination environment of the Na+ ion: three from the carbonyl groups of ligands and one O atom from a coordinating water mol-ecule. In the crystal, the bimetallic complexes are assembled into chains along the c-axis direction via O-H⋯O hydrogen bonds that involve the coordinating water mol-ecules and the phosphoryl groups.

Selective modification of the metal coordination environment in heavy alkaline–earth iodide complexes

The controlled formation of group 2 coordination complexes involves issues of metal acidity, ligand basicity, solvent effects, and steric pressure.

Synthetic, structural, NMR and catalytic studies of phosphinic amide-phosphoryl chalcogenides (chalcogen = O, S, Se) as mixed-donor bidentate ligands in zinc chemistry

Synthesis and catalytic activity of the title compounds are reported.

A columnar liquid crystal based on triphenylphosphine oxide—its structural changes upon interaction with alkaline metal cations

A triphenylphosphine oxide (TPPO) compound bearing 3,4,5-tridodecyloxybenzyloxy moieties exhibits a columnar liquid crystalline phase, and by changing its self-assembled structure, is responsive to alkaline metal cations due to cation-phosphine oxide interactions.