[10]CPP‐Based Inclusion Complexes of Charged Fulleropyrrolidines. Effect of the Charge Location on the Photoinduced Electron Transfer

Abstract

A number of non‐covalently bound donor‐acceptor dyads, consisting of C60 as the electron acceptor and cycloparaphenylene (CPP) as the electron donor, have been reported. A hypsochromic shift of the charge transfer (CT) band in polar medium has been found in [10]CPP⊃Li+@C60. To explore this anomalous effect, we study inclusion complexes [10]CPP⊃Li+@C60‐MP, [10]CPP⊃C60‐MPH+, and [10]CPP⊃C60‐PPyMe+ formed by fulleropyrrolidine derivatives and [10]CPP using the DFT/TDDFT approach. We show that the introduction of a positively charged fragment into fullerene stabilizes CT states that become the lowest‐lying excited states. These charge‐separated states can be generated by the decay of locally excited states on a nanosecond to picosecond time scale. The distance of the charged fragment to the center of the fullerenic cage and its accessibility to the solvent determine the strength of the hypsochromic shift.

Photoinduced electron transfer in host–guest complexes of double nanohoops

“…The obtained values for mono (Twin1 ⊃ C 60 , Twin2 ⊃ C 60 , and Twin3 ⊃ C 60 ) and bis (Twin1 ⊃ 2C 60 , Twin2 ⊃ 2C 60 , and Twin3 ⊃ 2C 60 ) adducts are shown in Table 1. As previously demonstrated for similar systems, dispersion interactions play a significant role in the stability of such complexes [65,66]. To confirm this, we used a Morokuma-type method of energy decomposition analysis (EDA) [67][68][69].…”

“…While CT states can be highly stabilized or destabilized by the solvent, the influence of solvation on LE states is often minimal. The equilibrium COSMO-like solvation model [66,73,74] with dichloromethane (DCM) as the solvent was used to evaluate the effect of the solvent on the excited states. All of the investigated complexes in GS have rather small dipole moments.…”

The Hunter Falls Prey: Photoinduced Oxidation of C60 in Inclusion Complex with Perfluorocycloparaphenylene

“…For example, ΔE int for the complex of C 60 with π‐extended corannulene bowl is only −31 kcal/mol, [29a] but the existence of such a complex in solution has been established experimentally [29b] . The dispersion interactions play a major role in the stability of the complex, as shown earlier for systems of a similar nature [11c,30] . To get more insight, we performed the energy decomposition analysis (EDA) of the interaction energy using a Morokuma‐type method [31] .…”

Bethe Salpeter Equation Spectra for Very Large Systems

“…In the last decade, cycloparaphenylenes (CPPs), also known as carbon nanohoops, have emerged as highly structurally tunable emitters, with rich size-dependent opto-electronic properties and host-guest chemistry. [43] While substantial DFT modeling has been completed on CPP+fullerene complexes, [35,[44][45][46] extraction of optical properties at this level of theory is difficult due to the characteristic charge transfer states in CPPs. Further, it has already been established that the BSE formalism is very accurate in predicting the properties of other fullerene-polymer complexes.…”