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Organic compounds always have a $\ce{C-H}$ bond. But can we make compounds having $\ce{C-D}$ bonds where D is the deuterium part like $\ce{CD4}$, $\ce{C2D5CHO}$, $\ce{C6D6}$ and other complex organic compounds? Overall, can we make organic compounds containing deuterium? Also, can we consider those compounds organic? Are the compounds stable? Give some example of preparatory reaction of those compounds.

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  • $\begingroup$ Um, I haven't heard of "deteurium bonds" to date. And don't forget to use Mathjax for chemical formulae formatting! $\endgroup$
    – M.A.R.
    Oct 4, 2015 at 17:23
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    $\begingroup$ Yes, we can, and they can be quite useful probes of chemical and biological processes. Yes, they are still considered organic. $\endgroup$
    – Jon Custer
    Oct 4, 2015 at 17:24
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    $\begingroup$ Just to give an example - $\ce{CDCl3}$ is widely used as an NMR solvent. $\endgroup$ Oct 4, 2015 at 17:27
  • $\begingroup$ @orthocresol As is $\ce{C6D6}$, which the question specifically asks for ;) $\endgroup$
    – Jan
    Oct 4, 2015 at 17:28
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    $\begingroup$ @NilayGhosh A solvent used for NMR. I'm going to quote from the Wikipedia page on proton NMR - "Simple NMR spectra are recorded in solution, and solvent protons must not be allowed to interfere. Deuterated solvents especially for use in NMR are preferred, e.g. deuterated water, D2O, deuterated acetone, (CD3)2CO, deuterated methanol, CD3OD, deuterated dimethyl sulfoxide, (CD3)2SO, and deuterated chloroform, CDCl3." $\endgroup$ Oct 4, 2015 at 17:32

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Deuterium occurs at around the 0.02% level in nature (natural abundance level). So all compounds that contain hydrogen will already contain a low level concentration of the deuterated isomer(s). So in fact, deuterated compounds do exist in nature.

Despite this low level of natural deuterium incorporation, the deuterium can still be detected by various spectroscopic techniques (mass spectrometry and nmr for example).

Further, organic compounds can be synthesized with deuterium in specific locations. These deuterated compounds are still considered organic compounds. Since deuterium is a stable nucleus (e.g. does not undergo radioactive decay), the compounds containing deuterium are also stable. Because the $\ce{C-D}$ bond is a bit shorter and therefore a bit stronger than the corresponding $\ce{C-H}$ bond, there is an isotope effect in reactions where these bonds are broken. Because the $\ce{C-H}$ bond is weaker, it will break up to 7 times faster than the corresponding $\ce{C-D}$ bond. This can have a significant effect on biological processes.

$\ce{D2O}$ and $\ce{D2}$ gas are relatively common and inexpensive materials that can be used to introduce deuterium into other molecules. Here are 2 examples involving the use of these materials for deuterium incorporation. In the first example $\ce{D2O}$ is used as the source of deuterium, in the second example deuterium gas is used to introduce the deuterium. If you google "organic preparation of deuterated compounds" you'll find many more examples.

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Specifically deuterated compounds are widely used in many areas of research and industry.

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  • $\begingroup$ Is halogen substitution always used? What about preparing deuterated acetylene C2D2 from CaC2 and heavy water? $\endgroup$
    – Rich
    Oct 25, 2019 at 2:45
  • $\begingroup$ @Rich Yes, that would be another (of many) useful approach. $\endgroup$
    – ron
    Nov 14, 2019 at 18:11

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