- Mechanism of the coupling of diazonium to single-walled carbon nanotubes and its consequences
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Due to its simplicity and versatility, diazonium coupling is the most widely used method for carbon nanotube (CNT) functionalization to increase CNT processability and add new functionalities. Yet, its mechanism is so far mostly unknown. Herein, we use kinetic analysis to shed light on this complex mechanism. A free-radical chain reaction is revealed by absorption spectroscopy and ESR. Metallic CNTs are shown to play an unexpected catalytic role. The step determining the selectivity towards metallic CNTs is identified by a Hammett correlation. A mechanistic model is proposed that predicts reactivity and selectivity as a function of diazonium electrophilicity and metallic-to- semiconducting CNT ratio, thus opening perspectives of controlled high-yield functionalization and purification.
- Schmidt, Gregory,Gallon, Salome,Esnouf, Stephane,Bourgoin, Jean-Philippe,Chenevier, Pascale
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- Photocatalyzed borylation using water-soluble quantum dots
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The synthesis of arylboronates by Sandmeyer-type reactions in the presence of water still remains a significant challenge. Herein, we report the use of water-soluble MPA-capped quantum dot (QD) photocatalysts for the borylation of diazonium salts in the presence of water. A biphasic system under mild acidic conditions remains critical to prevent decomposition and competitive disulphide bond formation. The present protocol offers a broader scope of substrates and borylating agents. Additionally, this catalytic system offers a significantly high turnover number (TON). The present methodology can effectively distinguish subtle reactivity differences between boronic acids and boronates. Mechanistic investigation suggests an excited-state electron transfer pathway.
- Chandrashekar, Hediyala B.,Maji, Arun,Halder, Ganga,Banerjee, Sucheta,Bhattacharyya, Sayan,Maiti, Debabrata
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supporting information
p. 6201 - 6204
(2019/06/07)
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- Visible-Light-Mediated Hydroxycarbonylation of Diazonium Salts
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A visible light-promoted catalytic photoredox hydroxycarbonylation was achieved on aryl diazonium salts whether preformed or generated in situ from the corresponding anilines. This strategy allows a straightforward access to a variety of carboxylic acids under mild conditions. (Figure presented.).
- Gosset, Cyrille,Pellegrini, Sylvain,Jooris, Romain,Bousquet, Till,Pelinski, Lydie
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supporting information
p. 3401 - 3405
(2018/08/06)
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- One-Pot Reactions for Synthesis of 2,5-Substituted Tetrazoles from Aryldiazonium Salts and Amidines
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One-pot sequential reactions of aryldiazonium salts with amidines followed by the treatment of I2/KI under basic conditions provide 2,5-disubstituted tetrazoles in moderate to excellent yields. This one-pot synthesis has several advantages such as mild reaction conditions, short reaction time, convenient workup, and high yields, making this methodology practical.
- Ramanathan, Mani,Wang, Yu-Hao,Liu, Shiuh-Tzung
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supporting information
p. 5886 - 5889
(2015/12/11)
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- Crown Cation Complex Effects. 12. Dissolution and Complexation of Arenediazonium Cations in Nonpolar Media. An Assessment of Solvent Effects and Reactivity by Infrared and Nuclear Magnetic Resonance Spectroscopy
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A number of arenediazonium salts (largely tetrafluoroborates) have been surveyed to determine their solubility properties and the influence of crown ethers and quaternary ammonium salts thereupon.Analysis has been by a variety of spectral techniques inclu
- Korzeniowski, Stephen H.,Leopold, Ahuva,Beadle, James R.,Ahern, Michael F.,Sheppard, William A.,et al.
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p. 2153 - 2159
(2007/10/02)
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