R. Craig Taylor

X-ray photoelecton spectroscopic (ESCA) study of 1,2-bis(diphenyl-phosphino)-ethane, 1-(diphenylphosphino)-2-(dimethylamino)-ethane and related compounds

Abstract ESCA spectra for compounds of the type φ 2 P-CH 2 CH 2 -Pφ 2 , φ 2 Pue5f8CHue5fbCHue5f8Pφ 2 , φPue5f8Cue5fcCue5f8Pφ 2 and, Me 2 Nue5f8CH 2 CH 2 ue5f8Pφ 2 are reported along with similar compounds having positive charges on one or both of the heteroatoms. For uncharged molecules, group electronegatives correlated with P (2 p ) binding energies. For molecules having a charged site, the inductive effect of the charged atom was a major factor determining binding energies for both heteroatoms. Among similar compound types, anion effects were absent. For molecules containing nitrogen, the smaller (CH 3 ) 2 N-group allowed anion shielding of the positive charge, causing smaller shifts than for similar compounds containing only phosphorus. Correlations between charge, calculated from Sanderson electronegatives, and P (2 p ) and N (1 s ) binding energies are reported.

Studies on the µ-(NN′)-ethylenediaminetetra-acetato-di-µ-oxo-bis-[oxotungstate(V)], [W2O4(edta)]2–, complex in aqueous solutions. Formation of an aquo-ion and redox properties

The aquation of [W2O4(edta)]2–(edta = ethylenediaminetetra-acetate) to W2O42+(or a closely related species) proceeds to completion in HCl 2 mol dm–3. First-order kinetics have been observed, with the rate constant (1.16 × 10–4 s–1 at 25 °C) in 2 mol dm–3 HCl some 60 times less than for the corresponding reaction of [Mo2O4(edta)]2–. With HClO4 2 mol dm–3 aquation is accompanied by oxidation to WVI. No aquation (or oxidation) has been observed with HClO4 107 dm3 mol–1 s–1 respectively. For the [IrCl6]2– reaction activation parameters are ΔH‡= 5.4 kcal mol–1 and ΔS‡=–13.8 cal K–1 mol–1 respectively. Rate constants (dm3 mol–1 s–1) for other oxidants, I= 0.10 mol dm–3, are [Fe(CN)6]3–(0.058), [Co(bipy)3]3+(2.0)(bipy = 2,2′-bipyridine), and I3–(ca. 20). The complex [W2O4(edta)]2– is a much stronger reducing agent than [Mo2O4(edta)]2–.

Synthesis and molecular structure of an inorganic zwitterion: trichloro{[2-(diphenylphosphinyl)ethyl]dimethylammonium}copper(II)

The solid-state structure of the title compound has been determined by X-ray crystallographic methods (Patterson and Fourier) from both film and automated diffractometer data. Crystals are monoclinic, and diffractometer results indicate space group Cc with Z= 8, cell dimensions: a= 12·713(1), b= 12·633(1), c= 24·474(2)A, and β= 91·05(1)°. The structure was refined to R 0·071 for 2709 independent reflections.The results clearly show the zwitterionic nature of the complex. The co-ordination polyhedron around each copper(II) atom is a distorted tetrahedron. The co-ordination sphere is comprised of the three anionic chloride ligands and the oxygen atom of the phosphinyl group. The overall solid-state packing of the individual molecules reflects the intermolecular hydrogen bonding between the proton on the nitrogen and the chlorine atoms. As a result, the molecules form hydrogen-bonded chains which run parallel to the c axis. Important bonds and angles are: Cu–O 2·00, P–O 1·50 A; Cu–O–P 145·5°.

Cobalt(II) complexes of “mixed” nitrogen–phosphorus cationic ligands

Cobalt(II) dihalides form inorganic zwitterion complexes of the type [CoX3–L+] where X = Cl, Br, I, and L is the 2-(diphenylphosphino)ethyldialkylammonium cation.

Synthesis and solid-state crystal structure of [2-(diphenylphosphinoyl)ethyl]diethylammonium dichlorocuprate(I), containing a discrete CuCl2– anion

[2-(Diphenylphosphino)ethyl]diethylamine, reacts with copper(II) chloride in ethanol or tetrahydrofuran to yield either [2-(diphenylphosphinoyl)ethyl]diethylammonium dichlorocuprate(I)(IV), or [2-(diphenylphosphino)ethyl]-diethylammonium dichlorocuprate(I)(III). Compound (IV) has been characterized by measurements of conductivity, magnetic susceptibility, and i.r. and u.v. spectra. Water in the solvents is apparently the source of both the proton and the oxygen atom required for formation of (IV). A three-dimensional X-ray structural analysis of (IV) was also undertaken. Crystals from either solvent are monoclinic, space group P21/c, a= 12·54(1), b= 9·119(8), c= 21·73(1)A, β= 123·10 (5)°, and Z= 4. The structure was solved by a combination of the symbolic-addition and heavy-atom procedures and refined by least squares to R 11·0% for 2661 visually estimated observed reflections. The structure consists of discrete cations and [CuCl2–] anions whose closest approach is Cu ⋯ O 3·74 A; the anion is near-linear, Cu–Cl 2·090(5)A, Cl–Cu–Cl 175·8(2)°.

The molecular structure of 2-(diphenylphosphine oxide)ethyldiethylammonium dichlorocuprate(I): single-crystal X-ray analysis

The product formed upon reaction of 2-(diphenylphosphino)ethyldiethylamine and copper(II) chloride in ethanol has been shown to be an ionic compound, 2-(diphenylphosphine oxide)ethyldiethylammonium dichlorocuprate(I) by single-crystal X-ray analysis: this is the first X-ray analysis of a discrete dichlorocuprate(I) anion.