I. Distribution of antimony (III) between hydrochloric acid and isopropyl ether. II. The infrared spectra and probable structures of some nitrogen-sulphur compounds

Abstract

Antimony (III) was extracted by isopropyl ether from solutions of HCl, HCl-HCl0_4, and HCl-NaCl. The ether and acid layers were analyzed for antimony (III) and chloride. On the basis of the variation of the distribution ratios with the aqueous HCl concentrations a model of the species of antimony (III) present in the HCl solution was constructed. The following constants relating the species to one another were calculated. K_(2-3) = [SbCl_3] a_(H_2O / [SbCl_2OH] a^2_(HCl) = 0.145 K_(3-4) = [SbCl^-_4] / [SbCl_3] a_(HCl) = 0.34 D_2 = [SbCl_2OH] _e / [SbCL_2OH] _a = 0.0080 D_3 = [SbCl_3] _e / [SbCl_3] _a = 0.062 Spectrophotometric measurements on antimony (III) in acid and ether solutions indicated the presence of a hydrate of SbCl_3 in the acid. Reasonable agreement was found between the results predicted by the model and the experimental values of the solubility of Sb_40_5Cl_2 in HCl, the potential of the antimony (III) - antimony (V) half cell in HCl, and the catalytic effect of antimony (III) on the hydrolysis of SbCl^-_6. The infrared spectra of the products of fluorinations of N_4S_4 were taken. CCl_4, CFCl_3, SO_2, SOF_2, SF_4, SF_6 and SiF_4 were identified as components of the mixture. Bands of four unknown compounds were found. Compound A with bands at 1375 and 644 cm^(-1) was identified as SNF on the basis of its instability and infrared spectrum. Compound B was identified as NSF_3 since it was not decomposed by heating nor was capable of being further fluorinated. The envelopes of the 1520, 819, and 774 cm^(-1) bands indicate that it is a symmetric rotor. Compound C with bands at 1340 and 1160 cm^(-1) was unidentified. Compound D with bands at 1340 and 1160 cm^(-1) was at first thought to be NSF but a force constant calculation led to an unreasonable structure. It is still unidentified. An approximate normal coordinate treatment of SNF led to k_(NS) = 10.4 millidynes/A and k_(NF) = 2.3 millidynes/A. These values indicate that the N-F bonding has considerable ionic character. Approximate force constants for NSF_3 were calculated and were found to correspond to the NSF_3 structure with normal single and triple bonds. No evidence was found for the existence of Glemser's SN_2F_2. His erroneous results could be explained by the presence of SO_2, SOF_2, and SF_4 as impurities in his product of the N_4S_4 fluorination.