Harry M. N. H. Irving

Irregular three-coordination in mercury: structures of phenyl- and methylmercury(II) dithizonate

[Hg(C6Hs)(CI3HIlN4S)] crystallizes in the monoclinic space group P2Jc with a = 5.991 (3), b = 20.68 (1), c = 17.129 (9) A,/~= 99.40 (5) °, Z = 4. [Hg(CH3)(CI3HIIN4S)] crystallizes in the triclinic space group Pl with a = 14.866 (7), b = 11.194 (6), c = 4.557 (3) A, a = 89.30 (5),/~= 95.85 (5), y= 97.62 (5) °, Z = 2. Final R = 0.058 and 0.061 respectively. In both structures the Hg atom exhibits planar, irregular three-coordination, the geometry at the Hg atom being approximately T-shaped, with the dithizone residue (C 13HllN4S-) acting as a bidentate ligand coordinating through S and N. The imino proton participates in a weak intramolecular hydrogen bond which stabilizes the N-N-C-N-N chain in an anti,s-trans configuration relative to the formal C=N double and C-N single bonds.

An absorptiometric determination of perchlorate by means of a novel coloured liquid anion exchanger

A novel liquid anion exchanger can be prepared from tetra-n-hexylammonium iodide and Erdmanns salt, (NH4)[Co(NH3)2(NO2)4]. When a solution of this quaternary erdmannate in a suitable organic solvent (emax = 15,700 at 355 mμ) is equilibrated with an aqueous solution of a salt, the coloured ermannate ion is displaced to a greater or less extent; the effect decreases in the order ClO4- > ClO3- > NO3- > Cl- > SO42- etc. The effects of changes in the organic solvent composition, of ionic strength, and of other variables on the position of equilibrium have been studied with a view to defining the optimum conditions for the absorptiometric determination of perchlorate ion (≧25 μ) in the presence of chlorate and other ions. Methods are proposed for eliminating those ions that form insoluble silver salts and to allow for the presence of substantial proportions of chlorate or nitrate ions.

Studies with dithizone: Part 35. A new look at the structure of dithizone in solution

The traditional view that solutions of dithizone in organic solvents comprise equilibrium mixtures of thione- and thiol-forms which are individually responsible for the characteristic strong absorption bands around 620 and 440 nm is examined critically. It is shown that experimental values of pH12, pK and R (the peak ratio) can legitimately be used in calculations although they are compounded of parameters (partition coefficients, acid dissociation constants, etc.) relating to both of the alleged tautomeric forms and the equilibrium constant, KT governing the interconversion. Published attempts to calculate KT from spectral data alone are shown to be unreliable.

Studies with dithizone: Part 33. effect of temperature on the spectrum in chloroform

Abstract The position and relative intensity of the two peaks in the visible absorption spectrum of dithizone dissolved in chloroform do not change on cooling from room temperature to −48°C. Thus either the two absorption peaks cannot be ascribed to two discrete species (thiol and thione tautomers), or the enthalpy of their interconversion is zero.

C-H⋯π(Ar)⋯Cl-C, C-Cl⋯π(Ar), Cl⋯Cl and other interactions in the crystal structure of 6-benzoyl-2,4-bis(trichloromethyl)-1,3-benzdioxin

The title compound is monoclinic,P21/n,Z=4,a=9.934(1),b=18.399(2),c=11.098(2)Å, β=111.08(1)°. The molecule can conveniently be visualized as a benzophenone molecule with one of the aromatic rings fused to a 1,3-dioxin ring which adopts a distorted envelope conformation withcis-trichloromethyl groups substituted at positions 2 and 4. An interaction, observed for the first time, involves a hydrogen atom and a chlorine atom from opposite sides of the same aromatic ring to give C-H⋯-π(Ar)⋯Cl-C. The parameters are H⋯ring-centroid 2.63 A, Cl⋯ring centroid 3.41 Å, H⋯ring-centroid⋯Cl 167°, C-H⋯ring centroid 159°, C-Cl⋯ring centroid 150.2°. The π(Ar) system is that of the unfused aromatic ring. A second π(Ar) ⋯ Cl-C interaction occurs but this time with the π(Ar) system of the fused aromatic ring. The Cl⋯Cl and Cl⋯O(=C) interactions form the familiar zig-zag pattern which has been noted for many chloroaromatic compounds.

C−Cl...π(Ar)...Cl−C, Cl...Cl and other interactions in the structures of two 6-substituted-2,4-bis(trichloromethyl)-1,3-benzdioxin's: (I) 6-carboxymethyl; (II) 6-propionyl, an antimethanogenesis food additive

AbstractC12H3Cl6O4, (I),Mr=428.91, triclinic,

The boat conformation of α-parachloral. Notes on the revised structures of α- andβ-parachloral

P\bar 1

Isomerism in parabutylchloral; x-ray crystallographic determinations of 2,4,6-tris(1′,1′,2′-trichloropropyl)-1,3,5-trioxanes

,a=9.197(1),b=9.336(2),c=9.830(1) Å, α=79.29(1), β=83.33(1), γ=85.38(1)°,V=822.16,Z=2,Dx=1.73 Mg m−3,F(000)=428, λ(MoKα)=0.71069 Å, μ=10.62 cm−1, room temperature, finalR=0.033 for 2573 unique counter reflections withFo>4σ(Fo). C13H10Cl6O3, (II),Mr=426.94, triclinic,