Synthesis,characterization and resolution of racemic (2-methylsulfinyl)phenylphosphonic acid methyl ester via its cinchoninium salts

The synthesis of new (2-methylsulfinyl)phenylphosphonic acid methyl and dimethyl esters in both racemic and non-racemic forms is reported. Resolution of the racemic phosphonic acid mono-ester 1 was accomplished via diastereomeric salt formation with cinchonine. The absolute stereochemistry of the phosphonic ester products was deduced from asymmetric sulfoxidation experiments and confirmed by chemical correlation with (S)-(−)-2-methylsulfinylaniline.     

Synthesis,structure, FAB mass spectrum,and magnetic property of a dodecanuclear cluster complex of chromium with hydrido ligands [Cr12S16(H)2(PEt3)10]

A dodecanuclear cluster complex of chromium [Cr₁₂S₁₆(H)₂(PEt₃)₁₀] was prepared by the reaction of a hexanuclear cluster complex [Cr₆S₈(H)(PEt₃)₆] with elemental sulfur, and characterized by the FAB mass spectroscopy and single-crystal X-ray structure analysis. Crystallographic data: [Cr₁₂S₁₆(H)₂(PEt₃)₁₀] · 2CH₂Cl₂ (207 K), triclinic, P1, a = 14.697(6) Å, b = 14.733(5) Å, c = 14.238(5) Å, α= 96.60(3)°, β= 109.77(3)°, γ= 65.69(3)°, Z= 1. This complex contains two octahedral Cr₆S₈ cluster cores linked by a Cr-Cr and two Cr-S bonds, and each core holds an interstitial hydrogen atom. The intercluster bonding mode is similar to those in the superconducting Chevrel-Sergent phases. The paramagnetic moment of the dodecanuclear cluster decreases remarkably at lower temperatures showing the antiferromagnetic coupling between the paramagnetic cluster centers.