New pyrazolino and pyrrolidino[60]fullerenes: the introduction of the hydrazone moiety for the formation of metal complexes

Abstract

The [3 + 2] cycloaddition reaction of C 60 with pyridine-derived hydrazones (acting as dipolar reagents) was successfully conducted resulting in fullerene derivatives 5a-b. The compounds were characterized by means of NMR, UV-Vis spectroscopy, and X-ray crystallography. The electrochemical behavior was also investigated. The fulleropyrazoline 5a exhibits anodically shifted reduction potentials of about 100 mV when compared with those for C 60 , whereas 5b exhibits cathodic shifts relative to pristine C 60 . The complexation reaction of 5b with metallic ions (Zn 2+ , Cd 2+ , and Fe 2+ ) was achieved. Job and Benesi-Hildebrand analysis confirmed the formation of complexes with a molar ratio of 1:1 and binding constants between 2.26 × 10 5 and 1.59 × 10 5 M À1 . Electrochemistry of these complexes showed a marked influence of the metal ion on the reduction potentials.

New chitosan-imine derivatives: from green chemistry to removal of heavy metals from water

“…On the other hand, compounds such as hydrazones are of interest in supramolecular chemistry since appropriately substituted hydrazones are able of acting as ligands in coordination chemistry [39,40], finding use as molecular switches [41][42][43][44][45][46], metallo-assemblies [47][48][49], among others [50,51].…”

Pyrazole-, isoxazole- and pyrrole-ring fused derivatives of C60: synthesis and electrochemical properties as well as morphological characterization

“…[6,6]-Adducts of C 60 are distinguished by signal at 430 nm. [29][30][31] The optical band gap (E opt g ) of C 60 -based compounds can be estimated from the absorption onsets (l onset ) of Uv-vis spectrum (Fig. 2) for each compound.…”

Síntesis regioespecífica y estudio electroquímico de dos derivados carboxílicos C60 solubles en agua

“…To analyze such effects, we recorded the cyclic voltammetry of the different derivatives in THF (Figure 6 and table 2). In this sense, it is important to emphasize that there are few reports of electrochemical studies of fullerene addends in polar solvents (Paolucci, et al, 1999;Romero, et al, 2017b) and that the addition of the different malonates to the fullerene cage structure is a good methodology to increase the solubility of these compounds. Fullerene has been considered for several electronic applications thanks to its remarkable ability to accept electrons.…”

“…To exploit these properties, exohedral functionalization of C 60 has become the "go-to" method to make the processing of these structures into more complex materials easier, partly because fullerene adducts are more soluble in common organic solvents than their pristine counterparts. Synthetic modifications have also been used to modulate the physical properties of the fullerene framework to insert it in several materials such as polymers (Giacalone & Martín, 2006), metal complexes (Romero, et al, 2017a;Zhou, et al, 2006), coordination polymers (Chen, et al, 2015;Peng, et al, 2013Peng, et al, , 2014, metalorganic frameworks (MOFs) (Minar, et al, 2015) and dendrimers (Nierengarten, et al, 2003), just to name a few.…”