Magnesium nitride

When measuring the boiling point of magnesium, Henri Étienne Sainte-Claire Deville and Henri Caron identified that molten magnesium they distilled covered itself by "small colorless and transparent needles which are destroyed fairly quickly by transforming into ammonia and magnesia". In their 1857 publication the chemists interpreted it as a likely nitride similar to those discovered by Friedrich Wöhler and Heinrich Rose.s:fr:Page:Comptes rendus hebdomadaires des séances de l’Académie des sciences, tome 044, 1857.djvu/406

It was indeed confirmed in 1862 when Friedrich Briegleb and Johann Georg Anton Geuther synthesized the compound on purpose and first studied it.{{Cite journal |last=Briegleb |first=Fr. |last2=Geuther |first2=A. |date=1862 |title=Ueber das Stickstoffmagnesium und die Affinitäten des Stickgases zu Metallen |url=https://books.google.com/books?id=netSAAAAcAAJ&pg=PA228 |journal=Justus Liebigs Annalen der Chemie |language=de |volume=123 |issue=2 |pages=228–241 |doi=10.1002/jlac.18621230212 |issn=1099-0690}}

• By passing dry, very pure nitrogen over heated magnesium at {{convert|800-850|C|F}} for 90 minutes:

:{{chem2|3 Mg + N2 → Mg3N2}}{{cite book |last1=Ehrlich |first1=P. |editor1-last=Brauer |editor1-first=Georg |title=Handbook of Preparative Inorganic Chemistry 1 |date=December 1, 1963 |publisher=Academic Press |location=New York, London |isbn=978-0121266011 |pages=916-917 |edition=Second |url=https://archive.org/details/Handbook_of_Preparative_Inorganic_Chemistry_1_2_Brauer/page/n939/mode/2up |access-date=29 March 2025 |language=en |chapter=Section 17: Alkaline Earth Metals}}

• By passing dry ammonia over heated magnesium at {{convert|800-850|C|F}} for 4 hours:

:{{chem2|3 Mg + 2 NH3 → Mg3N2 + 3 H2}}

This second method is preferred despite the additional time required due to the difficulty of fully purifying nitrogen gas to prevent the formation of unwanted oxides.

Magnesium nitride reacts with water to produce magnesium hydroxide and ammonia gas, as do many metal nitrides.

:{{chem2|Mg3N2(s) + 6 H2O(l) → 3 Mg(OH)2(aq) + 2 NH3(g)}}

In fact, when magnesium is burned in air, some magnesium nitride is formed in addition to the principal product, magnesium oxide.

Thermal decomposition of magnesium nitride gives magnesium and nitrogen gas (at 700-1500 °C).

At high pressures, the stability and formation of new nitrogen-rich nitrides (N/Mg ratio equal or greater to one) were suggested and later discovered.{{Cite journal|last1=Yu|first1=Shuyin|last2=Huang|first2=Bowen|last3=Zeng|first3=Qingfeng|last4=Oganov|first4=Artem R.|last5=Zhang|first5=Litong|last6=Frapper|first6=Gilles|date=June 2017|title=Emergence of Novel Polynitrogen Molecule-like Species, Covalent Chains, and Layers in Magnesium–Nitrogen Mg x N y Phases under High Pressure|journal=The Journal of Physical Chemistry C|volume=121|issue=21|pages=11037–11046|doi=10.1021/acs.jpcc.7b00474|issn=1932-7447}}{{Cite journal|last1=Wei|first1=Shuli|last2=Li|first2=Da|last3=Liu|first3=Zhao|last4=Li|first4=Xin|last5=Tian|first5=Fubo|last6=Duan|first6=Defang|last7=Liu|first7=Bingbing|last8=Cui|first8=Tian|date=2017|title=Alkaline-earth metal (Mg) polynitrides at high pressure as possible high-energy materials|journal=Physical Chemistry Chemical Physics|volume=19|issue=13|pages=9246–9252|doi=10.1039/C6CP08771J|pmid=28322368|bibcode=2017PCCP...19.9246W|issn=1463-9076}}{{Cite journal|last1=Xia|first1=Kang|last2=Zheng|first2=Xianxu|last3=Yuan|first3=Jianan|last4=Liu|first4=Cong|last5=Gao|first5=Hao|last6=Wu|first6=Qiang|last7=Sun|first7=Jian|date=2019-04-25|title=Pressure-Stabilized High-Energy-Density Alkaline-Earth-Metal Pentazolate Salts|journal=The Journal of Physical Chemistry C|volume=123|issue=16|pages=10205–10211|doi=10.1021/acs.jpcc.8b12527|s2cid=132258000|issn=1932-7447}} These include the {{chem2|Mg2N4}} and {{chem2|MgN4}} solids which both become thermodynamically stable near 50 GPa.{{Cite journal|last1=Laniel|first1=Dominique|last2=Winkler|first2=Bjoern|last3=Koemets|first3=Egor|last4=Fedotenko|first4=Timofey|last5=Bykov|first5=Maxim|last6=Bykova|first6=Elena|last7=Dubrovinsky|first7=Leonid|last8=Dubrovinskaia|first8=Natalia|date=December 2019|title=Synthesis of magnesium-nitrogen salts of polynitrogen anions|journal=Nature Communications|volume=10|issue=1|pages=4515|doi=10.1038/s41467-019-12530-w|issn=2041-1723|pmc=6778147|pmid=31586062|bibcode=2019NatCo..10.4515L}} The {{chem2|Mg2N4}} is composed of exotic cis-tetranitrogen {{chem2|N4(4−)}} species with N-N bond orders close to one. This {{chem2|Mg2N4}} compound was recovered to ambient conditions, along with the {{chem2|N4(4−)}} units, marking only the fourth polynitrogen entity bulk stabilized at ambient conditions.

When isolating argon, William Ramsay passed dry air over copper to remove oxygen and over magnesium to remove the nitrogen, forming magnesium nitride.

Magnesium nitride was the catalyst in the first practical synthesis of borazon (cubic boron nitride).{{cite journal

| author = R. H. Wentorf, Jr.

| authorlink = Robert H. Wentorf, Jr.

| date=March 1961

| title = Synthesis of the Cubic Form of Boron Nitride

| journal = Journal of Chemical Physics

| volume = 34

| issue = 3

| pages = 809–812

| doi = 10.1063/1.1731679

| bibcode = 1961JChPh..34..809W

}}

Robert H. Wentorf, Jr. was trying to convert the hexagonal form of boron nitride into the cubic form by a combination of heat, pressure, and a catalyst. He had already tried all the logical catalysts (for instance, those that catalyze the synthesis of diamond), but with no success.

Out of desperation and curiosity (he called it the "make the maximum number of mistakes" approach{{cite web

| url = http://www.winstonbrill.com/bril001/html/article_index/articles/51-100/article61_body.html

| title = Discovering a Material That's Harder Than Diamond

| accessdate = June 28, 2006

| author = Robert H. Wentorf, Jr.

| date=October 1993

| work = R&D Innovator

}}), he added some magnesium wire to the hexagonal boron nitride and gave it the same pressure and heat treatment. When he examined the wire under a microscope, he found tiny dark lumps clinging to it. These lumps could scratch a polished block of boron carbide, something only diamond was known to do.

From the smell of ammonia, caused by the reaction of magnesium nitride with the moisture in the air, he deduced that the magnesium metal had reacted with the boron nitride to form magnesium nitride, which was the true catalyst.

Magnesium nitride has also been applied to synthesize aluminum nitride nanocrystals, cubic boron nitride and nitrides of aluminum and Group 3 {{Cite journal|last1=Zong|first1=Fujian|last2=Meng|first2=Chunzhan|last3=Guo|first3=Zhiming|last4=Ji|first4=Feng|last5=Xiao|first5=Hongdi|last6=Zhang|first6=Xijian|last7=Ma|first7=Jin|last8=Ma|first8=Honglei|title=Synthesis and characterization of magnesium nitride powder formed by Mg direct reaction with N2|journal=_Journal of Alloys and Compounds|year=2010 |volume=508|issue=1|pages=172–176|doi=10.1016/j.jallcom.2010.07.224}} It has also been proposed as an intermediate in a fossil-fuel-free nitrogen fixation process.{{Cite journal|last1=Hu|first1=Yang|last2=Chen|first2=George Z.|last3=Zhuang|first3=Lin|last4=Wang|first4=Zhivong|last5=Jin|first5=Xianbo|title=Indirect electrosynthesis of ammonia from nitrogen and water by a magnesium chloride cycle at atmospheric pressure|journal=Cell Reports Physical Science|year=2021 |volume=2|issue=5|page=100425|issn=2666-3864|doi=10.1016/j.xcrp.2021.100425|bibcode=2021CRPS....200425H |s2cid=235555007 |doi-access=free}}

{{reflist}}

• {{cite journal |author1=Wu, P. |author2=Tiedje, T. | year = 2018| title = Molecular beam epitaxy growth and optical properties of Mg₃N₂ films | journal = Applied Physics Letters | volume = 113 | issue = 8 | pages = 082101 | publisher = AIP | doi = 10.1063/1.5035560 |bibcode=2018ApPhL.113h2101W |s2cid=125356057}}

{{Magnesium compounds}}

{{Nitrides}}

{{DEFAULTSORT:Magnesium Nitride}}

Category:Nitrides

Category:Magnesium compounds