Redox Properties of Mixed Lutetium/Yttrium Nitride Clusterfullerenes: Endohedral Lu_xY_3−xN@C₈₀(I) (x=0–3) Compounds

Abstract

The redox behavior of mixed lutetium/yttrium nitride clusterfullerenes of the series Lu(x)Y(3-x)N@C(80)(I(h), x = 0-3) is studied for the first time by means of cyclic voltammetry, fast-scan cyclic voltammetry, square-wave voltammetry, and electron paramagnetic resonance (EPR) spectroelectrochemistry. A reversible single-electron-transfer process, which does not result in an EPR signal, is detected during the anodic oxidation sweep of cyclic voltammetry experiments performed at different temperatures (296 and 360 K). The cathodic reduction sweep reveals a rather complex response for all the four clusterfullerenes--with up to three irreversible reduction steps. By correlating the results of fast-scan and square-wave voltammetry and combining them with simulations of the voltammograms, we are able to propose a reduction mechanism for the Lu(x)Y(3-x)N@C(80)(I) (x = 0-3) fullerenes.

An endohedral redox system in a fullerene cage: the Ce based mixed-metal cluster fullerene Lu2CeN@C80

“…In the cathodic range, Lu 2 CeN@C 80 exhibits two electrochemically irreversible reduction steps with peak potentials (E pc ) at À1.43 and À1.92 V vs. Fc +/0 (corresponding peak potentials in square-wave voltammetry measurements are at À1.39 and À1.88 V). With slight variation of the peak potentials, this behavior is typical for all non-Sc M 3 N@C 80 NCFs studied to date, including Er 3 N@C 80 , Dy 3 N@C 80 , Tm 3 N@C 80 , Gd 3 N@C 80 , Nd 3 N@C 80 , Pr 3 N@C 80 and Lu x Y 3Àx N@C 80 , 3,4,[25][26][27]29,38 (for comparison, Fig. 7c shows cyclic voltammogram of Y 3 N@C 80 measured in the same conditions).…”

“…3,4,12,[21][22][23][24] In particular, the redox behaviour of NCFs has been studied in great detail, and it was found that the endohedral cluster is usually redox-inert, while the oxidation or reduction of NCFs occurs by changing the charge state of the carbon cage. 3,4,[25][26][27][28][29] Since the yield of NCFs in synthesis is much higher than that of the conventional metallofullerenes, it enhances the possibilities for research of the properties and applications of fullerenes.…”

Fullerenes

“…152 The redox behaviour of mixed lutetium/yttrium nitride clusterfullerenes of the series LuxY 3Àx N@C 80 (x = 0-3) was studied for the first time by means of cyclic voltammetry and electron paramagnetic resonance. 153 Metallofullerene encapsulating the radioactive tracer Ac-225, Ac@C 82 was obtained and its electronic properties were studied by radiochromatography. 154 The structures of two newly synthesised endohedral fullerenes, Tm@C 94 and Ca@C 94 have been determined by single crystal X-ray diffraction.…”

Influence of the Encapsulated Clusters on the Electrochemical Behaviour of Endohedral Fullerene Derivatives: Comparative Study of N‐Tritylpyrrolidino Derivatives of Sc3N@Ih‐C80 and Lu3N@Ih‐C80

“…The redox behavior of M 3 N@C 80 fullerenes have been intensively studied in recent years and most of them show similar redox patterns with irreversible reduction processes. [4,[7][8][9][10] Only very recently Popov and coworkers reported that TiSc 2 N@I h -C 80 exhibits reversible reduction processes. [11] Although the cause of irreversibility remains unclear, tremendous progress has been made in this field.…”

“…Moreover, the first reduction potential, compared to that of the parent Sc 3 N@I h -C 80 , is dramatically shifted from À1.26 V to À1.06 V, making it the most easily reduced M 3 N@I h -C 80 compound. [4,[8][9][10] It is notewor- À1.54…”