Hydrogen sullide

Fluorine, chlorine, bromine, and iodine react with H S to form the corresponding halogen acid. Metal sullides are formed when H S is passed inlo solutions of the heavy metals, such as Ag. Ph. Cu. and Mn. This rcaelion is responsible lor the tarnishing of Ag and is the hasis for the separation of these metals in classical wet qualitative analytical methods. Hydrogen sullide reacts with many organic compounds. 

A closely related synthesis utilizes alkynic epoxides, which add hydrogen sullide in the presence of a base to form thiophenes in good yield. For example, when the epoxide (184) was stirred in an aqueous solution of barium hydroxide with slow addition of hydrogen sulfide gas, and the product extracted after neutralization with acetic acid, the substituted thiophene (186) was obtained in 60-70% yield (53ZOB1569). In these experiments R1 =Me or Et, R2 = H or Me and R3 = Ph. The same synthetic method was used to produce a thiophene having an optically active substituent, with relatively little racemization. In this case R1 = EtC HMe while R2 and R3 = H, but the yield was equivalent (73JOC2361). This reaction also undoubtedly proceeds via an intermediate (185), a structure related to a 1 -mercapto-1,3-butadiene. 

Diplienylcarbodiimide can be prepared by the removal of the rlrments of hydrogen sullide from N,N -diphenyllhi< urea by... 

In the atmosphere of the Northern equatorial Atlantic Ocean the concentration of hydrogen sullide has been recently studied by Slatt et al. (1978) using a sensitive fluorescence technique. They report concentrations ranging from 5 x 10 3 to 5 x 10-2 ppb(0.0C76-0.C76/igm"3 STP)which are much lower than the mean level of 0.2 ppbm used by Friend (1973). Slatt and her co-workers also state, on the basis of their results, that the residence time of H2S in the atmosphere cannot be more than a few hours. On the other hand, they estimate that the oceanic production rate of this substance given by Friend is probably correct. 

Compound Carbon dioxide Hydrogen sullide Carbon Nitrogen monoxide... 

MOLECULE, hi the traditional sense, a molecule is the smallest particle of a chemical substance capable of independent existence with retention of all its chemical properties. Molecules comprise one or more atoms which need not be of the same kind. Only the rare, or noble gases form single-atom or monatomic molecules. All other elements form bi-. Iri. quudrt-. etc. atomic molecules, e.g.. hydrogen. H ozone. O-, phosphorus. P4 and sulfur, Sx or hydrogen chloride. IICI sodium sullide. Na S. aluminum chloride, AlClu carbon tetrachloride. C CI. and so on. 

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