March, 1950
DERIVATIVES O F 3-THIOPHENETHIOL
1289
Conclusion phous series. This was further substantiated by the preparation of mixed sodium copper zinc salts 1. The following new compounds have been b y addition of sodium chromate solution to a n prepared and described, members of the isomorequimolar mixture of zinc and copper trichromate phous series M:0.4Mii0.4CrOa.3H20 : NatOe4CuO. solution until all zinc and copper were precipitated. 4Cr03.3Hz0, Naz0-4Co0.4Cr03.3H20. They The first crystals formed were a brownish maroon, form characteristic tabular diamond-shaped crysindicating a predominance of the copper salt. As tals over a range of PH and concentration. precipitation progressed, a continuous graduation 2. A new series of compounds, of the general in color to reddish-yellow was noted with no formula (NH4)20.4Mii0.4Cr03.NH3.2H~0, or change in crystal form, a zinc-rich salt precipitat- 3NHs.4MiiO-4CrO3.3H20, crystallizing in sixing directly on the copper-rich crystals first sided plates or aggregates, has been noted. The formed. A typical product was uniform, brownish- zinc.and cobalt salts have been prepared and dered in color, composed mostly of aggregates of scribed. well-defined crystals of the general shape previ3. Precipitates have been obtained approxiously described. Single crystals showed a crystal mating the above formulas in the case of ammoangle of 62-63'. The crystals were identified as nium copper chromate, ammonium nickel chrobelonging t o the general family of compounds b y mate, sodium nickel chromate, and potassium analysis for sodium and chromium: Found: nickel chromate. These materials exhibit subNa20, 7.49; CrOa, 47.52; molecular ratio, CrOa: stantial variation in appearance and composition NaaO = 3.94. Calculated (Cu salt) : Na20, 7.43; with varying precipitation conditions. They apCrOa, 47.94; (Zn salt) Na20, 7.37; CrOa, 47.55. pear t o be solid-solution type compounds with Isomorphism evidently exists, but there is a con- the property of forming definite crystals with a n siderable discrepancy in solubility of the two excess or deficiency of certain components of the salts, the copper salt being the more insoluble a t lattice. the lower pH. -2. The series of compounds falls within a logiAn interesting development in the case of the cal pattern, as determined by ionic ratios. The ammonium double salts is the existence of a new non-existence of the sodium cadmium chromate is series of compounds of the' general formula in accord with this pattern, as are the non-stoichio3NH34M1'O.4Cr03.3H2O. The exact structure of metric compounds formed. these compounds is unknown, but a simple con5 . Preliminary data have been presented cept of their formation is the replacement of a wa- which may be helpful in the eventual determinaby tion of the structure of these compounds. ter molecule in (NH4)20.4Mii0.4Cr03.3H20 NH,. They appear to crystallize in hexagonal RESEARCH LABO~TORIES plates in those cases where discrete crystals have MUTUALCHEMICAL COMPANY OF AMERICA RECEIVED JANUARY 7, 1949 heen observed. BALTIMORE, MARYLAND
A DIVISION OF SOCONY-VACUUM DEVELOPMENT DEPARTMENT]
[ C V S T R I B U T I O N FROM SOCONY-VACUUM LABORATORIES,
O I L CO., I N C . ,
RESEARCH AND
Derivatives of 3-Thiophenethiol BY J. W. BROOKS,E. G. HOWARD' AND J. J. WEHRLE The preparation of thiophene by the reaction of sulfur with n-butane a t elevated temperatures has been reported by Rasmussen, Hansford and Sachanen.2 These investigators obtained approximately one pound of so-called "tar" for every pound of thiophene produced. The tar has been investigated and found to contain 20-30% of 3thiophenethiol. A possible mechanism for the formation of this compound is given. In order t o identify the thiol obtained from the tar as :
