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Nikodem Kuźnik,1 Mateusz M Tomczyk,1 Marzena Wyskocka,1 Łukasz Przypis,1 Artur P Herman,1 Rafał Jędrysiak,1 Krzysztof K Koziol,2 Slawomir Boncel11Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland; 2Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UKAbstract: Iron-filled multiwall carbon nanotubes (Fe@MWCNTs) were functionalized toward a variety of potential magnetic resonance imaging contrast agents. Oxidized Fe@MWNCTs were covered with PEG5000 via direct esterification or using acyl chloride derivatives. Alternatively, the latter were functionalized with an aminophenol ligand (Fe@O-MWCNT-L). Moreover, pristine Fe@MWCNTs were functionalized with N-phenylaziridine groups (Fe@f-MWCNT) via [2+1] cycloaddition of nitrene. All of these chemically modified nanotubes served as a vehicle for anchoring Fe3+ ions. The new hybrids – Fe(III)/Fe@(f-/O-)MWCNTs – containing 6%–14% of the “tethered” Fe3+ ions were studied in terms of the acceleration of relaxation of water protons in nuclear magnetic resonance. The highest transverse relaxivity r2=63.9±0.9 mL mg-1 s-1 was recorded for Fe(III)/Fe@O-MWCNT-L, while for Fe(III)/Fe@f-MWCNT, with r2=57.9±2.9 mL mg-1 s-1, the highest impact of the anchored Fe(III) ions was observed. The T1/T2 ratio of 30–100 found for all of the nanotube hybrids presented in this work is a very important factor for their potential application as T2 contrast agents. Increased stability of the hybrids was confirmed by ultraviolet–visible spectrophotometry.Keywords: multiwall carbon nanotubes, Fe3+, transverse relaxation time T2, MRI contrast agent

The synthesis and characterization of a family of indene-C 60 adducts obtained via Diels-Alder cycloaddition [4 + 2] are reported. The new C 60 derivatives include indenes with a variety of functional groups. These adducts show lowest unoccupied molecular orbital energy levels to be at the right position to consider these compounds as electron-transporting materials for planar heterojunction perovskite solar cells. Selected derivatives were applied into inverted (p-i-n configuration) perovskite device architectures, fabricated on flexible polymer substrates, with large active areas (1 cm 2 ). The highest power conversion efficiency, reaching 13.61%, was obtained for the 6'-acetamido-1',4'-dihydro-naphtho[2',3':1,2][5,6]fullerene-C 60 ( NHAc-ICMA ). Spectroscopic characterization was applied to visualize possible passivation effects of the perovskite's surface induced by these adducts., Competing Interests: The authors declare no competing financial interest., (© 2021 American Chemical Society.)

Single-walled carbon nanotubes (SWCNTs) have been modified with ester groups using typical organic radical chemistry. Consequently, traps for mobile excitons have been created, which enhanced the optical properties of the material. The proposed methodology combines the benefits of mainstream approaches to create luminescent defects in SWCNTs while it simultaneously avoids their limitations. A step change was achieved when the aqueous medium was abandoned. The selection of an appropriate organic solvent enabled much more facile modification of SWCNTs. The presented technique is quick and versatile as it can engage numerous reactants to tune the light emission capabilities of SWCNTs. Importantly, it can also utilize SWCNTs sorted by chirality using conjugated polymers to enhance their light emission capabilities. Such differentiation is conducted in organic solvents, so monochiral SWCNT can be directly functionalized using the demonstrated concept in the same medium without the need to redisperse the material in water.

A copper-catalyzed iodination of carbazoles has been developed. Barluenga's reagent IPy2BF4 is used to generate a soft electrophilic halonium species for the iodination of the carbazoles. This report represents the first concept of copper-catalyst-promoted electrophilic halogenation of carbazoles. We demonstrated numerous applications of this methodology synthesizing diverse carbazole derivatives, i.e., both electron-rich and electron-deficient systems.