Sulfur and iodine

Phosphonic acid and hydrogen phosphonates are used as strong but slow-acting reducing agents. They cause precipitation of heavy metals from solutions of their salts and reduce sulfur dioxide to sulfur, and iodine to iodide in neutral or alkaline solution. 

Of the several syntheses available for the phenothiazine ring system, perhaps the simplest is the sulfuration reaction. This consists of treating the corresponding diphenylamine with a mixture of sulfur and iodine to afford directly the desired heterocycle. Since the proton on the nitrogen of the resultant molecule is but weakly acidic, strong bases are required to form the corresponding anion in order to carry out subsequent alkylation reactions. In practice such diverse bases as ethylmagnesium bromide, sodium amide, and sodium hydride have all been used. Alkylation with (chloroethyl)diethylamine affords diethazine (1), a compound that exhibits both antihista-minic and antiParkinsonian activity. Substitution of w-(2-chloroethyl)pyrrolidine in this sequence leads to pyrathiazine (2), an antihistamine of moderate potency. 

Chlorpromazine (33) can probably be considered the prototype of the phenothiazine major tranquilizers. The antipsychotic potential of the phenothiazines was in fact discovered in the course of research with this agent. It is of note that, despite the great number of alternate analogs now available to clinicians, the original agent still finds considerable use. The first recorded preparation of this compound relies on the sulfuration reaction. Thus, heating 3-chlorodiphenylamine (30) with sulfur and iodine affords the desired phenothiazine (31) as well as a lesser amount of the isomeric product (32) produced by reaction at the 2 position. The predominance of reaction at 6 is perhaps due to the sterically hindered nature of the 2 position. Alkylation with w-C3-chloropropyl)dimethylamine by means of sodium amide affords chlorpromazine (33). ... 

The only references of antimony available in the literature were the reactions in ethanolic solutions. Nowak et al. [133] have reported the sonochemical synthesis of SbSI gel by irradiating an ethanolic solution containing elemental antimony, sulfur and iodine for 2 h by the ultrasound of 35 kHz and 2 W/cm2 at 50°C. They also... 

Beattie, I.R., Ozin, G.A., and Perry, R.O., Gas phase Raman spectra of P4, P2, As4 and As2. Resonance fluorescence spectrum of 80Se2. Resonance fluores-cence-Raman effects in the gas-phase spectra of sulfur and iodine. Effect of pressure on the depolarization ratios for iodine,. Chem. Soc., Perkin I, 2071, 1970. 

Sa I (solid). According to Ogier7 there is no heat effect on mixing sulfur and iodine. 

As early as 1804 solutions of non-metals such as sulfur and iodine in oleums were reported to produce highly colored solutions but the nature of the solutes was unknown. From the mid 1960s, Gillespie s group adduced reliable evidence to indicate that solutions such as these and others in HS03F and HF contained the polyatomic halogen cations It, if", IJ, If, Brf and Brf and the chalcogen cations listed in Table 2. 

Anal. Calcd. weight of [S7l][AsF6], based on AsFj 4.00g. Found 3.89g. Calcd. weight of unreacted sulfur and iodine 1.79 g. Found 1.78 g. 

Sulfur and iodine. Beck and Strobel (1986) subjected various RSI compounds, R = Ce-Nd, Sm, Gd-Dy, to elevated temperatures (800°C) and pressures (0.5-4.0-GPa). Under normal pressures the R = Ce Sm compounds exhibit the SmSI-type structure and the R = Gd-Dy compounds the GdSI-type structure. Under elevated pressure the R = Gd-Dy compounds transform to the SmSl-type structure, with GdSI itself transforming under additional pressure to the a-CeSI-modification. The R = /3-Ce-Sm compounds convert to the a-CeSI modification. 

With sulfur and iodine, in which the bonds have little ionic character (electronegativity of copper, 1.9 of sulfur and iodine, 2.5), the cuprous compounds are the more stable. 

V. V. Brazhkin, S. V. Popova, and R. N. Voloshin, Pressure-temperature phase diagram of molten elements selenium, sulfur and iodine, Physica B265, 64-71 (1999). 

Sulfur halides include several fluorides (SF2, SF4, SFe, S2F2, SSF2, S2F10), some chlorides (SCI2, SCI4, S2CI2), and some poorly characterized bromides. Even a compound of sulfur and iodine is claimed however, the S—I bond is notoriously unstable and cannot be formed by direct reaction of the elements. 

Many nonmetals are gases at room temperature. These include nitrogen, oxygen, fluorine, and chlorine. One nonmetal, hromine, is a liquid. The solid nonmetals include carhon, phosphorus, selenium, sulfur, and iodine. These solids tend to he brittle rather than malleable and ductile. Some nonmetals are illustrated in Figure 3.4. 

Table 2.2 Some of the complexes formed by some of the ligands in Table 2.1. This table endeavours to demonstrate that any one metal may well form complexes with different numbers of ligands and that many complexes are not monomeric (there are sulfur and iodine bridging atoms in the two cases not explicitly detailed). Note that when two different complexes contain the same number of ligands it does not necessarily mean that the geometrical arrangements of the ligands is the same in the two cases. Note, too, that the attempt to show variety means that this table does not properly reflect the fact that the majority of complexes contain metal ions bonded to six ligands...

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