N2 tsuas yog paub cov qauv nruab nrab thiab ruaj khov (allotrope) ntawm nitrogen. Synthesis ntawm neutral N3 thiab N4 tau tshaj tawm ua ntej tab sis tsis tuaj yeem raug cais tawm vim muaj kev tsis ruaj khov heev. Cov kws tshawb fawb tam sim no tau ua tiav hauv chav tsev kub synthesis ntawm hexanitrogen (N6), ib qho tshiab nruab nrab allotrope ntawm nitrogen uas lawv tuaj yeem ntxiab hauv argon matrices ntawm 10K. Synthesis ntawm N6 tau lees paub spectroscopically thiab cov allotrope tshiab tau pom tias muaj kev ruaj khov. Cov tshuaj tiv thaiv decomposition yog exothermic nrog tso tawm ntau lub zog tawm tswv yim ua tau daim ntawv thov raws li lub zog cia tshuab raws li qhov xav tau ntawm cov kua nitrogen txias. Txawm li cas los xij, qhov kev npaj ntawm qhov ruaj khov tshiab, nruab nrab allotrope ntawm nitrogen yog ib qho kev loj hlob tseem ceeb hauv chemistry.
Allotropes yog cov qauv sib txawv ntawm cov khoom uas ua los ntawm kev sib txawv ntawm kev sib txuas ntawm cov atoms ntawm tib lub caij. Lawv muaj cov khoom sib txawv raws li lawv cov qauv thiab yog cov nqi nruab nrab uas muaj nyob rau hauv cov ntaub ntawv nonradical. Piv txwv li, pob zeb diamond, graphite, thiab graphene yog nruab nrab, ruaj khov allotropes ntawm carbon. Zoo li O2 thiab O3 (ozone) allotropes ntawm oxygen.
Yuav ua li cas txog nruab nrab, ruaj khov cov ntaub ntawv ntawm nitrogen? Nyob zoo N2 tsuas yog paub ruaj khov allotrope ntawm nitrogen. Ob tug lwm yam nruab nrab allotropes N3 thiab N4 tau tshaj tawm ua ntej xyoo 1956 thiab 2002 raws li tab sis tsis tuaj yeem raug cais tawm vim muaj kev tsis ruaj khov heev.
Chemists tau tam sim no ntse synthesized C2h-symmetric hexanitrogen (C2h-N6) ntawm chav tsev kub. [C2h symmetry yog ib hom symmetry pom nyob rau hauv lub ntiaj teb tshuaj. AC2h-symmetric molecule muaj ob-fold tig axis (C2) thiab kab rov tav daim iav dav hlau (σh)].
Hexanitrogen (N6), qhov tshiab nruab nrab allotrope ntawm nitrogen tau tsim nyob rau hauv chav tsev kub los ntawm cov roj-theem cov tshuaj tiv thaiv ntawm chlorine (Cl2) los yog bromine (Br2) nrog silver azide (AgN3) nyob rau hauv lub siab txo. Qhov no tau ua raws los ntawm cryogenic ntxiab hauv argon matrices ntawm 10 Kelvin. Cov kws tshawb fawb kuj tseem tuaj yeem npaj hexanitrogen hauv daim ntawv ntshiab raws li cov yeeb yaj kiab ntawm 77 Kelvin (qhov kub ntawm cov kua nitrogen).
Hexanitrogen (N6) yog li npaj nyob rau hauv lub chaw soj nstuam yog tus yam ntxwv spectroscopically thiab tau pom tias yuav ruaj khov.
Thaum decomposition, hexanitrogen (N6) tawg rau hauv peb N2 molecules. Cov tshuaj tiv thaiv yog exothermic nrog kev tso tawm ntawm 185.2 kcal ib mole ntawm lub zog, uas yog 2.2 thiab 1.9 npaug siab dua lub zog tso tawm ntawm decomposition TNT thiab HMX los ntawm qhov hnyav. Vim hais tias ntawm lub zog loj tso tawm ntawm decomposition, hexanitrogen (N6) tej zaum yuav yog ib qho kev cog lus zoo huv si-khoom siv, txawm li cas los xij uas yuav tsum tau ua kom hexanitrogen ntawm cov kua nitrogen kub hauv qab 77K uas tej zaum yuav tsis ua haujlwm zoo rau lub zog cia-txheej txheem.
Txawm hais tias txhua daim ntawv thov yav tom ntej, chav ntsuas kub ntawm qhov tshiab nruab nrab molecular allotrope ntawm nitrogen uas tuaj yeem raug daig hauv qhov chaw cryogenic yog qhov kev loj hlob tseem ceeb hauv chemistry.
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References:
- Qian, W., Mardyukov, A. & Schreiner, PR Kev npaj ntawm ib qho nruab nrab nitrogen allotrope hexanitrogen C2 hnu 6. xwm 642, 356–360 (2025). Published: 11 June 2025. DOI: https://doi.org/10.1038/s41586-025-09032-9
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, a new neutral allotrope of nitrogen which they could trap in argon matrices at 10K. The synthesis of N6 was confirmed spectroscopically and the new allotrope was demonstrated to be stable.){kind=link}