Hydrogen disulfide

Structure

The connection of atoms in the hydrogen disulfide molecule is . The structure of hydrogen disulfide is similar to that of hydrogen peroxide, with C2 point group symmetry. Both molecules are distinctly nonplanar. The dihedral angle between the and planes is 90.6°, compared with 111.5° in . The bond angle is 92°, close to 90° for unhybridized divalent sulfur.

Synthesis

Hydrogen disulfide can be synthesised by cracking polysulfanes () according to this idealized equation: : The main impurity is trisulfane ().

Reactions

Upon contact with water or alcohols, hydrogen disulfide readily decomposes under ambient conditions to hydrogen sulfide and sulfur.

It is more acidic than hydrogen sulfide, but the pKa has not been reported.

In organosulfur chemistry, hydrogen disulfide adds to alkenes to give disulfides and thiols.

Quantum tunneling and its suppression in deuterium disulfide

The deuterated form of hydrogen disulfide, deuterium disulfide (dideuterodisulfane), has a similar geometry to , but its tunneling time is slower, making it a convenient test case for the quantum Zeno effect, in which frequent observation of a quantum system suppresses its normal evolution. Trost and Hornberger have calculated that while an isolated molecule would spontaneously oscillate between left and right chiral forms with a period of 5.6 milliseconds, the presence of a small amount of inert helium gas should stabilize the chiral states, the collisions of the helium atoms in effect "observing" the molecule's momentary chirality and so suppressing spontaneous evolution to the other chiral state.

Health effects

In high concentrations, it can cause dizziness, disorientation and ultimately unconsciousness.

Historic literature

• Georg Brauer: Handbook of Preparative Inorganic Chemistry Volume I, page 391, Wiley, 1963.
• von Richter, Victor: Translated by Edgar F Smith, "A Text-Book of Inorganic Chemistry", Page 111, P. Blakiston, Son & Co., 1893

References

References

1. (2003). "Topic in Current Chemistry".
2. De, A. K.. (2001-01-15). "A Text Book of Inorganic Chemistry". Imperial College Press.
3. [http://www.rbltd.co.uk/?PAGEID=10520 Hazardous Reagents], Robinson Brothers
4. (2009). "Hund's Paradox and the Collisional Stabilization of Chiral Molecules". Phys. Rev. Lett..
5. [https://www.uni-due.de/~hp0198/pubs/physicstoday_cday.pdf Month-long calculation solves 82-year-old quantum paradox], Physics Today, September 2009, p. 16
6. Stein, Wilkinson, G. (2007). "Seminars in general adult psychiatry". Royal College of Psychiatrists.