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1. Direct Crystallization of Diamine Radical Cations: Carbon‐Nitrogen Bond Formation from the Reaction of Triphenylamine with TiCl 4 , TiBr 4 , or SnCl 4 versus Carbon‐Carbon Bond Formation with SbCl 5 **

   https://doi.org/10.1002/chem.202104631  

   Roy, Mrittika ; Walton, Jeffrey H. ; Fettinger, James C. ; Balch, Alan L. ( February 2022 , Chemistry – A European Journal)

   Direct synthesis of diamine radical cations in crystalline form proceeding through oxidation of triphenylamine followed by the formation of a new C−N bond is reported. Although the oxidative coupling of triphenylamine is well studied, diamine products are rarely captured in their radical cation state. The neutral diamine most frequently obtained from this reaction pathway is N,N,N’,N’‐tetraphenylbenzidine. Herein, the capture of radical cations of diamines in crystalline form in one step starting with neutral triphenylamine was demonstrated, and the formation of two products (the radical cations of N,N,N′,N′‐tetraphenyl‐1,4‐benzenediamine or N,N,N′,N′‐tetraphenylbenzidine) depending on the oxidizing agent used was observed. The radical species are characterized by single‐crystal X‐Ray diffraction, electron paramagnetic resonance spectroscopy, and optical spectroscopy.

    

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2. sp Carbon Chains Surrounded by sp 3 Carbon Double Helices:  Directed Syntheses of Wirelike Pt(C⋮C) n Pt Moieties That Are Spanned by Two P(CH 2 ) m P Linkages via Alkene Metathesis

   https://doi.org/10.1021/ja071612n  

   de Quadras, Laura ; Bauer, Eike B. ; Mohr, Wolfgang ; Bohling, James C. ; Peters, Thomas B. ; Martín-Alvarez, José Miguel ; Hampel, Frank ; Gladysz, John A. ( July 2007 , Journal of the American Chemical Society)
3. sp Carbon Chains Surrounded by sp 3 Carbon Double Helices:  Coordination-Driven Self-Assembly of Wirelike Pt(C⋮C) n Pt Moieties That Are Spanned by Two P(CH 2 ) m P Linkages

   https://doi.org/10.1021/ja0716103  

   Stahl, Jürgen ; Mohr, Wolfgang ; de Quadras, Laura ; Peters, Thomas B. ; Bohling, James C. ; Martín-Alvarez, José Miguel ; Owen, Gareth R. ; Hampel, Frank ; Gladysz, John A. ( July 2007 , Journal of the American Chemical Society)
4. Carbon Dioxide Promotes Dehydrogenation in the Equimolar C 2 H 2 ‐CO 2 Reaction to Synthesize Carbon Nanotubes

   https://doi.org/10.1002/smll.201703482  

   Shi, Wenbo ; Peng, Yue ; Steiner, III, Stephen A. ; Li, Junhua ; Plata, Desiree L. ( January 2018 , Small)

   The equimolar C₂H₂‐CO₂reaction has shown promise for carbon nanotube (CNT) production at low temperatures and on diverse functional substrate materials; however, the electron‐pushing mechanism of this reaction is not well demonstrated. Here, the role of CO₂is explored experimentally and theoretically. In particular,¹³C labeling of CO₂demonstrates that CO₂is not an important C source in CNT growth by thermal catalytic chemical vapor deposition. Consistent with this experimental finding, the adsorption behaviors of C₂H₂and CO₂on a graphene‐like lattice via density functional theory calculations reveal that the binding energies of C₂H₂are markedly higher than that of CO₂, suggesting the former is more likely to incorporate into CNT structure. Further, H‐abstraction by CO₂from the active CNT growth edge would be favored, ultimately forming CO and H₂O. These results support that the commonly observed, promoting role of CO₂in CNT growth is due to a CO₂‐assisted dehydrogenation mechanism.

    

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5. Attributing Past Carbon Fluxes to CO 2 and Climate Change: Respiration Response to CO 2 Fertilization Shifts Regional Distribution of the Carbon Sink

   https://doi.org/10.1029/2022GB007478  

   Quetin, Gregory R. ; Famiglietti, Caroline A. ; Dadap, Nathan C. ; Bloom, A. Anthony ; Bowman, Kevin W. ; Diffenbaugh, Noah S. ; Liu, Junjie ; Trugman, Anna T. ; Konings, Alexandra G. ( February 2023 , Global Biogeochemical Cycles)