Hydrogen ditelluride

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Hydrogen ditelluride
Hydrogen ditelluride
  Tellurium, Te
  Hydrogen, H
Names
IUPAC name
Hydrogen ditelluride
Systematic IUPAC name
Ditellane
Other names
ditellane
Dihydrogen ditellanide
Identifiers
3D model (
JSmol
)
ChEBI
ChemSpider
239518
  • InChI=1S/H2Te2/c1-2/h1-2H
    Key: JVCDLODDVKFSTM-UHFFFAOYSA-N
  • [TeH][TeH]
Properties
H2Te2
Molar mass 257.22 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Hydrogen ditelluride or ditellane is an unstable

weak force
.

Production

Hydrogen ditelluride can possibly be formed at the tellurium cathode in electrolysis in acid.[2] When electrolysed in alkaline solutions, a tellurium cathode produces ditelluride Te2−2 ions, as well as Te2− and a red polytelluride. The greatest amount of ditelluride is made when pH is over 12.[3]

Apart from its speculative detection in electrolysis, ditellane has been detected in the gas phase produced from di-sec-butylditellane.[1][4]

Properties

Hydrogen ditelluride has been investigated theoretically, with various properties predicted. The molecule is twisted with a C2 symmetry. There are two enantiomers. Hydrogen ditelluride is one of the simplest possible unsymmetrical molecules; any simpler molecule will not have the required low symmetry. The equilibrium geometry (not counting zero point energy or vibrational energy) has bond lengths of 2.879 Å between the tellurium atoms and 1.678 Å between hydrogen and tellurium. The H−Te−Te angle is 94.93°. The angle of lowest energy between the two H−Te bonds (the dihedral angle between the Ha−S−S and S−S−Hb planes) is 89.32°. The trans configuration is higher in energy (3.71 kcal/mol), and the cis would be even higher (4.69 kcal/mol).[5]

Being

Z boson exchanges between the nucleus and electrons.[6] It is proportional to the cube of the atomic number, so is stronger in tellurium molecules than others higher up in the periodic table (O, S, Se). Because of parity violation, the energy of the two enantiomers differs, and is likely to be higher in this molecule than most molecules, so an effort is underway to observe this so-far undetected effect. The tunneling effect is reduced by higher masses, so that the deuterium form, D2Te2 will show less tunneling. In a torsional vibrational mode, the molecule can twist back and forward storing energy. Seven different quantum vibration levels are predicted below the energy to jump to the other enantiomer. The levels are numbered vt = 0 up to 6. The sixth level is predicted to be split into two energy levels because of quantum tunneling.[7] The parity violation energy is calculated as 3×10−9 cm−1 or 90 Hz.[7]

The different vibrational modes for H2Te are symmetrical stretch of H−Te, symmetrical bend of H−Te−Te, torsion, stretch Te−Te, asymmetrical stretch H−Te, asymmetrical bend of H−Te−Te.[7] The time to tunnel between enantiomers is only 0.6 ms for 1H2Te2, but is 66000 seconds (18 h 20 min) for the tritium isotopomer T2Te2.[7]

Related

There are organic derivatives, in which the hydrogen is replaced by organic groups. One example is bis(2,4,6-tributylphenyl)ditellane.[8] Others are diphenyl ditelluride and 1,2-bis(cyclohexylmethyl)ditellane.

References