20.500.12556/RUL-169266 Host−guest interactions in the C$_{59}$N$^•$$\subset$[10]CPP supramolecular radical A remarkable stability of a supramolecular radical comprising an azafullerene (C$_{59}$N$^•$) radical sterically protected by a [10]cycloparaphenylene ([10]CPP) nanoring, C$_{59}$N$^•$$\subset$[10]CPP, has recently been observed by various experimental probes. In order to investigate the host−guest interaction in these supramolecular complexes, we carried out electron paramagnetic resonance (EPR) measurements, theoretically supported by density functional theory (DFT) calculations. The continuous wave (CW) EPR spectrum shows the presence of two active spin components: C$_{59}$N$^•$$\subset$[10]CPP monomers that can in certain cases polymerize into oligomeric radicals. Two- and three-pulse electron spin echo envelope modulation (ESEEM) measurements allow for determination of experimental hyperfine coupling constants for $^{13}$C and $^1$H atoms and also show the strong coupling to the $^{14}$N atom adjacent to the radical C of the azafullerene. These experimental hyperfine coupling constants reasonably agree with those calculated for the DFT optimized supramolecular structures. The results are consistent with a small spin delocalization from the guest (C$_{59}$N$^•$) to the host ([10]CPP), thereby explaining weak but non-negligible interaction between them. Our study demonstrates that ESEEM experiments in alliance with DFT computations can offer valuable insights into the radical host−guest structures. physical chemistry carbon chemical structure electron paramagnetic resonance spectroscopy energy levels quantum mechanics fizikalna kemija true false true Angleški jezik Slovenski jezik Članek v reviji 2025-05-21 10:22:23 2025-05-21 10:22:24 2025-05-22 04:03:48 0000-00-00 00:00:00 2025 0 0 Str. 9057-9065 iss. 19 Vol. 129 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544 1932-7447 10.1021/acs.jpcc.4c07474 236551683 tanuma-et-al-2025-host-guest-interactions-in-the-c59n-10-cpp-supramolecular-radical.pdf tanuma-et-al-2025-host-guest-interactions-in-the-c59n-10-cpp-supramolecular-radical.pdf 1 CF57E9478B175929C88F223C2AB64964 290ac383491910937a7ca49c31f4c3d9b66f6beca3a9c9aa6468f6e470a3fcd8 d84f8e47-361b-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=210531 https://pubs.acs.org/doi/10.1021/acs.jpcc.4c07474 0 b24e468f-361b-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=210530 Fakulteta za matematiko in fiziko 0 0 0