Jason C. Yarbrough

Synthesis, characterization and crystal structure of a zinc bis-dithiocarboxylate derivative

Abstract The zinc(II) complex, Zn(3,5-di-t-butyl-4-hydroxybenzene-dithiocarboxylate)2(pyridine) (3) was obtained by the reaction of Zn(CH3CN)4(BF4)2 with the sodium salt of 3,5-di-t-butyl-4-hydroxybenzene-dithiocarboxylate (1) with subsequent recrystallization from pyridine. The latter salt (1) was prepared by the deprotonation of 2,6-di-t-butylphenol with NaH in THF, followed by reaction with carbon disulfide at ambient temperature. The structure of complex 3 was established by X-ray crystallography and shown to be of a distorted trigonal bipyramidal geometry with one sulfur atom from each of the dithiocarboxylate ligands occupying the axial sites. By way of contrast, Na(2,4-di-t-butylphenolate) was found to react with CS2 to afford the xanthate derivative, Na(O-2,4-di-t-butylphenyldithiocarbonate) (4).

Intermolecular hydrogen-bonding in the solid-state structure of CpFe(CN)2(PTAH): Structural and spectral comparisons with its [K][CpFe(CN)2PTA] salt

Abstract The salt K[CpFe(CN)2PTA] (1) has been synthesized from the photolysis of K[CpFe(CN)2CO] and 1,3,5-triaza-7-phosphaadamantane (PTA) in methanol. Protonation of the salt by hydrogen ion exchange employing DOWEX 50 WX8-100 ion exchange resin yielded the complex CpFe(CN)2PTAH (2). The solid-state structures of both compounds have been determined by X-ray crystallography. Protonation was shown via ν(CN) and 31P-NMR to occur at one of the PTA nitrogens. Furthermore, it was found in the solid-state of the protonated structure that intermolecular hydrogen-bonding occurs between the cyanide nitrogen of one molecule and the PTA nitrogen of another molecule. The average FeCCN distance for 1 is 1.877(11) A. FeCCN distances for complex 2 differ significantly at 1.839(12) and 1.940(12) A, with the shorter bond length associated with the hydrogen-bonded CN group. Spectral (ν(CN) and 31P-NMR) characterization of the complexes and their potential use as precursors to double metal cyanide derivatives are reported.

Synthesis and crystal structure of [H2B(3-Phpz)2]2Zn

Our attempts to synthesize [H2B(3-Phpz)2]Zn(acetate) from K[H2B(3-Phpz)2] and anhydrous zinc acetate has instead resulted in the formation of the 2:1 complex, [H2B(3-Phpz)2]2Zn. This derivative was isolated and crystallized from THF at 10°C. Its structure has been defined as a distorted tetrahedron with an average Zn‐N bond distance of 2.011(1) A, as revealed by X-ray crystallography. As anticipated, this complex is inactive at catalyzing the coupling of cyclohexene oxide and carbon dioxide.