Lead(II) and cadmium(II) compounds with 2,4-dichlorophenoxyacetic acid (2,4D) and 2-(2,4-dichlorophenoxy)-propionic acid (2,4DP): Synthesis and properties

The paper presents the conditions under which compounds of the commercial herbicides, 2,4-dichlorophenoxyacetic acid (2,4D; C₈H₆O₃Cl₂) and 2-(2,4-dichlorophenoxy)-propionic acid (2,4DP; C₉H₈O₃Cl₂), with lead(II) and cadmium(II) are formed and the results of the examination of their properties.On the basis of the elemental analysis and Pb and Cd determination, the following molecular formulae for the obtained compounds were proposed: Pb(C₈H₅O₃Cl₂)₂.H₂O, Cd(C₈H₅O₃Cl₂)₂.₂H₂O, Pb(C₉H₇O₃Cl₂)2·H₂O and Cd(C₉H₇O₃Cl₂)₂·H₂O. Water solubility of the synthesized complexes at room temperature was examined. X-ray powder analysis was carried out. The discussion of IR spectra and conductivity data is presented. Thermal decomposition of these compounds in air was studied by TG/MS methods.This revised version was published online in November 2005 with corrections to the Cover Date.     

Carbonyl and trifluorophosphine adducts of bis(2,4-dimethylpentadienyl)titanium and bis(2,4-dimethylpentadienyl)vanadium

The syntheses of mono(carbonyl) and mono(trifluorophosphine) adducts of bis(2,4-dimethylpentadienyl)titanium and bis(2,4-dimethylpentadienyl)vanadium are described. Characterization has been achieved by routine spectral and analytical procedures. Detailed ¹H and ¹³C NMR studies, as well as electron paramagnetic resonance and comparative infrared studies have been carried out in order to gain further understanding of the electronic nature of pentadienylmetal compounds, particularly compared to cyclopentadienylmetal compounds. Thus, infrared and EPR studies of V(C₅H₅)₂(CO) and V(2,4-C₇H₁₁)₂(CO) suggest that the withdrawal of electron density by the 2,4-dimethylpentadienyl ligand is considerably greater than that by the cyclopentadienyl ligand     

(2,4-Di-(tert-butyl)-6-methylphenyl)dithiophosphorane

Use of the 2,4-di-(tert-butyl)-6-methylphenyl radical permits stabilization of the corresponding dithiophosphorane (I). The analogous diselenophosphorane could not be detected as the monomer. This compound undergoes intramolecular addition of the C-H bond of the ortho-tert-butyl group at the P=Se bond with formation of the corresponding diselenophosphonic acid (III). Intermediate selenophosphine oxide (IV) was trapped as its salt with triethylamine (V).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1654–1656, July, 1991.     

Ni(II) and Co(II) complexes with 2,4-dichlorophenoxyacetic acid and 2-(2,4-dichlorophenoxy)-propionic acid

Nickel(II) and cobalt(II) complexes with the commercial herbicides 2,4-dichlorophenoxyacetic acid (2,4D; C₈H₆O₃Cl₂) and 2-(2,4-dichlorophenoxy)-propionic acid (2,4DP; C₉H₈O₃Cl₂) were prepared and characterized. On the basis of the results of elemental analysis and Ni and Co determination, the following molecular formulae were proposed for the obtained compounds: Ni(C₈H₅O₃Cl₂)₂·6H₂O, Co(C₈H₅O₃Cl₂)₂·6H₂O, Ni(C₉H₇O₃Cl₂)₂·2H₂O and Co(C₉H₇O₃Cl₂)₂·2H₂O. X-ray powder analysis was carried out. The IR, electronic (VIS) spectra and conductivity data were discussed. Water solubility of the synthesized complexes at room temperature was examined. Thermal decomposition of the compounds was studied. Dehydration processes occur during heating in air. The anhydrous compounds decompose via different intermediate products to oxides. TG/MS studies indicate formation of gaseous mass fragments of decomposition including H₂O⁺, OH⁺, CO₂ ⁺, HCl⁺, Cl₂ ⁺, CH₃Cl⁺, CH₂O⁺, C₆H₆ ⁺ and other. This revised version was published online in August 2006 with corrections to the Cover Date.     

Syntheses of N-(2,4-Dinitrophenyl)nitroazoles

Several N-(2,4-dinitrophenyl)nitroazoles which cannot be obtained by direct nitration of N-phenylazoles have been prepared by condensation of 2,4-dinitrofluorobenzene with the appropriate nitroazoles. The structures of the products are assigned on the basis of their proton magnetic resonance spectra; in all the examples studied, condensations occur at positions remote from the nitro group of the nitroazole.     

DSC determination of the fusion and sublimation enthalpy of bis(2,4-pentanedionato)beryllium(II) and tris(2,4-pentanedionato)aluminium(III)

The sublimation enthalpy of bis(2,4-pentanedionato)beryllium(II) and of tris(2,4-pentanedionato)aluminium(III) has been determined by differential scanning calorimetry as 85.3 ± 3.5 kJ mole^?1 and 125.6 ± 3.2 kJ mole^?1, respectively. The corresponding fusion enthalpies are 15.67 ± 0.74 and 28.71 ± 1.34 kJ mole^?1, respectively.