5-Dehydro-m-xylylene

{{#if:103.14 g/molC₈H_{7|! style="background: #F8EABA; text-align: center;" colspan="2" | Properties}

5-Dehydro-m-xylylene
5-Dehydro-m-xylylene
IUPAC name 5-dehydro-1,3-quinodimethane
Other names 5-dehydro-m-xylylene, DMX
Identifiers
CAS number	681440-83-5
Molecular formula	C8H7
Molar mass	103.14 g/mol
14pxY (verify) (what is: 10pxY/10pxN?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

5-Dehydro-m-xylylene (DMX) is an aromatic organic triradical and the first known organic molecule to violate Hund's Rule.

Its electronic ground state is an "open-shell doublet" rather than a quartet; that is, it contains three low-spin coupled unpaired electrons in three singly occupied molecular orbitals. Because there are radical electrons in both spin states, this compound is said to exhibit antiferromagnetism. Though similar ground states are observed in molecules containing transition metal atoms, it is unprecedented in organic molecules. The 5-dehydro-m-xylylene anion (DMX^-) has also been studied extensively. It has a triplet ground state consisting of a phenyl anion and a m-xylylene biradical.

External links

• Physics web - Radical molecule breaks the rules
• Purdue University Department of Chemistry - ‘Rule-breaking’ moleculefa:۵-دهیدرو-ام-زایلیلن