Fulleropyrrolidine Derivatives Research Articles

In silico analysis: Fulleropyrrolidine derivatives against HIV-PR mutants and SARS-CoV-2 Mpro

Abstract Approximately 37.9 million people living with HIV (PLWH) are at risk of severe consequences from COVID-19. Urgent development of tailored treatments for PLWH, who have historically been excluded from vaccine trials, is crucial. The present study introduces some modified fulleropyrrolidine derivatives with chalcogen atoms (O, S, or Se) and hydroxymethylcarbonyl (HMC) groups to target 11 single and double HIV-1 protease (HIV-PR) mutations and the main protease of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 Mpro). The inhibitory activities of these derivatives are computationally examined through molecular docking, molecular dynamic simulations for 200 ns, and Lipinski’s rule of five (RO5). Fourier-transform infrared spectroscopy spectra and thermodynamic properties are calculated and analyzed using Density Functional Theory B88-PW91 method. The results indicate that the suggested O-compounds obey three parameters of the RO5 and HMC forms hydrogen bonds with studied viral proteases. Compounds with O and S additives display a high binding affinity with negative binding energy values for HIV-PR mutations (A71V-I84V, V77I-I84V, and I84V-L90M) and SARS-CoV-2 Mpro. The compounds with S and Se additives shift to lower frequencies of the major vibrational bands. Specifically, compound 1, with two oxygen additives, emerges as the most effective in inhibiting both HIV-PR mutations and SARS-CoV-2 Mpro.

Novel [60]fullerene polymers: Part 2: Synthesis and polymerisation processes through acrylation of N-(4-hydroxyphenyl)-o-hydroxy-2-phenyl fulleropyrrolidine derivatives and their monomers

Following on from part 1 of this paper where linear C60 polymers were synthesised, part 2 describes the synthesis of crosslinked and branched chain C60 polymers so that the amount of C60 content in the polymer, the number averaged molecular weight “Mn” and the weight averaged molecular weight “Mw” may be increased. This paper reviews the method in which fulleropyrrolidines were prepared by [3 + 2] cycloaddition of azomethine ylides to [60]fullerene cage through the use of N-(4-hydroxyphenyl) glycine in conjunction with benzaldehyde derivatives. Numerous types of [60]fullerene polymers were synthesised through fulleropyrrolidine acrylic monomers. In this study, the cycloaddition process was selected because it provides a powerful tool for fullerene functionalisation, as a result very stable cycloadducts are formed. The addition of azomethine ylide was found to provide a versatile method for the derivatization of [60]fullerene. In this case, the synthesis of functionalised C60 and novel branched chain and crosslinked network of fullerene polymers has been investigated. The first step in this study was to prepare dihydroxy fulleropyrrolidines by [3 + 2] cycloaddition of azomethine ylide to [60]fullerene. The fulleropyrrolidine monomer having multiple functional groups was put up by the reaction of –OH groups of fulleropyrrolidine with acryloyl chloride in the presence of a base in an alcoholic solution. FT-IR, Mass spectra,1H NMR and UV techniques were used to characterise the reaction products obtained. Benzoyl Peroxide was used as a free radical initiator to polymerise the monomer in dimethylformamide. DMF is a highly suitable solvent for this procedure because both C60 monomer and polymer are soluble. In this work, the process parameters such as time of reaction, reaction temperature, mole ratio, type of solvent, and quantity of reagents used were varied in so as to obtain the highest yields of fulleropyrrolidines, monomers and polymers.

Novel [60]Fullerene Polymers: Part 2: Synthesis and Polymerisation Processes Through Acrylation of N-(4-Hydroxyphenyl)-O-Hydroxy-2-Phenyl Fulleropyrrolidine Derivatives and Their Monomers

Novel [60]Fullerene Polymers: Part 2: Synthesis and Polymerisation Processes Through Acrylation of N-(4-Hydroxyphenyl)-O-Hydroxy-2-Phenyl Fulleropyrrolidine Derivatives and Their Monomers

Multifunctional Molecular Design of a New Fulleropyrrolidine Electron Transport Material Family Engenders High Performance of Perovskite Solar Cells

Abstract[6,6]‐phenyl‐C61‐butyric acid methyl ester remains indispensable as the electron transport material (ETM) for perovskite solar cells (PSCs), but its synthesis involves complicated multisteps with low productivity. In contrast, the potential of synthesizing simpler fulleropyrrolidine derivatives has long been overlooked, and little has been understood regarding their structure‐dependent effects on photovoltaic (PV) performance. Herein, seven novel fulleropyrrolidine derivatives (F1–F7) are deliberately designed, synthesized, and comprehensively characterized in both solution and thin‐film states and subsequently investigated as ETMs for PSCs. Notably, the F4 delivers the highest power conversion efficiencies over 20% of devices, which surpass all reported fulleropyrrolidine ETMs due to its optimal photoelectric property. Moreover, the structure‐dependent effects of the fullerenes on PV parameters are uncovered, including solubility, intermolecular interaction, packing structure, and charge‐transfer ability, which can guide the future design of high‐performance and stable fullerene ETMs for PSCs.

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

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.

Fullerene bisadduct stabilizers: The effect of different addition positions on inhibiting the autocatalytic decomposition of nitrocellulose absorbed nitroglycerin

To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose (NC)/nitroglycerine (NG), we synthesized N-(4-methoxy) phenylpyrrolidine-C60 and four different of bis(N-(4-methoxy) phenylpyrrolidine)-C60 compounds through Prato reaction. Their structures were characterized by UV–vis, 1H NMR, 13C NMR, high-resolution mass spectroscopy, and single-crystal X-ray diffraction. Their stabilization effect to NC/NG were investigated using differential scanning calorimetry, methyl violet, vacuum stabilization effect, weight loss, and accelerating rate calorimeter tests. The results indicated these compounds had excellent stabilization effect to NC/NG. The stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C60. Moreover, the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different, and its stabilization effect to NC is also different. The stabilization effect order of different bisadduct isomers to nitrocellulose is as follows: e-edge > trans-2> cis-2> trans-3. Electron paramagnetic resonance (EPR) and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/NG. The EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide, and their ability is better than that of the monoadduct and C60, which is consistent with the results of stabilization effect performance test.

Doping alkali metal ions and introducing electron donor groups to fulleropyrrolidine derivatives: Large second-order nonlinear optical responses

The present study is focused on the nature of the structure-properties relationships of the 2,5-diaryl fulleropyrrolidine (1) derivatives by the density functional theory (DFT). 1 derivatives are designed and investigated, which are modified by electron donor groups and doped with alkali metal ions (1-D, M@1 and M@1-D, D = –CH3, –OCH3, –NH2; M = Li+, Na+, K+). Surprisingly, M@1-D compounds show a remarkable NLO response compared to 1-D and M@1. The K+@1-NH2 possesses the largest βtot value of 4.58 × 103 a.u.. Furthermore, the Uv–vis absorption spectrum by the time-dependent (TD-DFT) method is carried out to study tendency of the NLO responses for 1-D, M@1 and M@1-D. Calculated maximum absorption wavelength of K+@1-NH2 is significantly red-shifted compared to 1-NH2 and K+@1. The current work presents that 2,5-diaryl fulleropyrrolidine modified by introducing electron donor groups and doping alkali metal ions is a good candidate for well-performance NLO nanomaterial.

Mapping molecular electrostatic potential (MESP) for fulleropyrrolidine and its derivatives

Mapping molecular electrostatic potential (MESP) maps for chemical structure has become of great concern. Since it may explain valuable information about the interaction, active sites as well as determining the nature of chemical addition, through which a molecule is most probable to undergo; either electrophilic or nucleophilic addition. Calculations at a DFT high theoretical level and MESP maps for fulleropyrrolidine and its derivatives were carried out. The relation between total dipole moment (TDM) and the constructed MESPs were also investigated. Three different series of fulleropyrrolidine derivatives; ortho, meta and para, were presented. Results show that positioning the same element at different sites may change significantly TDM of the structure. The electron density of the fullerene structure appears as a red ellipse shape indicating an extremely negative region that is most likely to undergo nucleophilic reactions. The addition of electronegative substitutes; O and N, creates negative potentials at the terminal of the structure referring that electrophilic reactions are most probable there. The negative potential of fullerene core has the main role in determining the TDM direction.

A Comparative Study on Structure of [60] and [70] Fulleropyrrolidine Derivatives with N-Methyl

Density functional theory Dmol3 was employed to optimize a series of [60] and [70] fulleropyrrolidine derivatives. A comparative study showed that the difference of optimized geometrical structure between [60] and [70] fulleropyrrolidine derivatives with same substituent group was a little. The HOMO of fulleropyrrolidine derivatives with the same substituent group apart from C60-D and C70-D mainly focused on the same position, furthermore, the HOMO hardly focused on the pyrrolidine. However, the LUMO of all fulleropyrrolidine derivatives focused on the fullerene. Similarly, apart from C60-D and C70-D, the value of Δ E of [70] fulleropyrrolidine derivatives was larger than that of [60] fulleropyrrolidine derivatives.

Metallocenyl-containing and Unsaturated Fulleropyrrolidine Derivatives: Synthesis and Hydrogenation

The possibility of Pd/C-catalyzed hydrogenation of ferrocenyl, cymantrenyl, and ruthenocenyl derivatives of N-methyl-2-(3-chlorovinyl)fulleropyrrolidine and N-methyl-2-(2-styryl)fulleropyrrolidine with hydrogen was elucidated. A new compound, N-methyl-2-(3-chlorovinyl-3-ruthenocenyl)fulleropyrrolidine, was synthesized.

Interface engineering of compact-TiOx in planar perovskite solar cells using low-temperature processable high-mobility fullerene derivative

Interface engineering plays a promising strategy to produce highly efficient planar heterojunction (PHJ) perovskite solar cells. The deep trap states on the compact-TiOx surface leading to a large leakage current and recombination of charge carriers. To solve the problems, interfacial engineering of electron collecting layer (ECL) compact-TiOx by a thin-layer of one-step solution-processed and low-cost organic material is applied. In contrast, commonly used PCBM is still expensive material. Herein, a new, low-temperature processable higher potential of [60]fulleropyrrolidine derivatives named as N-phenyl[60]fulleropyrrolidines (PNP) was introduced as an interfacial modification of ECL compact-TiOx with the varying thickness of 10, 20, and 30nm to replace the commonly used PCBM in PHJ perovskite solar cells. The modified surface morphology was achieved by introducing PNP interfacial layers that enhanced the surface-energy properties of the cells in terms of enhanced photocurrent. Compared with PCBM, PNP features a higher electronic mobility and stronger hydrophobic nature. The enhancement of power conversion efficiency was obtained from 5.12% to 8.23%, with an increase in short-circuit current density (Jsc) from 11.90 to 21.44mAcm−2 and fill factor (FF) from 0.49 to 0.56 owing to insertion of optimum 10-nm-thickness PNP that led to more efficient electron transport and charge extraction in the solar cell performances. The present work provides an important sign in the aspects to the low-cost mass production of perovskite solar cells.

Optical, wetting and electrical properties of functionalized fulleropyrrolidine thin films

Fulleropyrrolidine derivatives acts as an electron acceptor in the fabrication of solar cells and other optoelectronic devices. In this investigation thin film of functionalized fulleropyrrolidines were fabricated and studied their photo-physical properties. Surface morphology of the thin films was investigated through AFM and FE-SEM. The results suggested that large dependence on structure vs molecular packing. The long alkyl chain substituted C60 were assembled in the form of nanorods. C60- C60 intermolecular distance were measured, the films were with good absorption and exhibits n-type semiconducting behavior. The films were having high contact angle and can be effectively used for fabricating semiconducting devices with self- cleaning property.

Interfacial Reaction of Fulleropyrrolidines Affecting Organic Photovoltaic Performance.

PSS). To clarify the effect of basic fulleropyrrolidine derivatives, we synthesized compounds with an N-benzyl substituent group and fabricated organic photovoltaic (OPV) cells using this N-benzyl fulleropyrrolidine. A device structure with the ITO/PEDOT:PSS/organic layer (PTB7:fulleropyrrolidine)/Ca/Al showed high series resistance, short-circuit current density (Jsc), and low fill factor (FF) values. However, OPV cells having an inverted structure, without the PEDOT:PSS layer, contributed good device performance. We were able to reproduce the high series resistance in a model experiment using aqueous ammonia vapor to treat the PEDOT:PSS layer. Our results indicated that the activity of the PEDOT:PSS layer was affected by the basicity of the fulleropyrrolidines. These results also explain why this phenomenon does not occur at the interface of OPV devices when conventional [6,6]-phenyl C61 butyric acid methyl ester is used as an acceptor material. This finding would contribute to enhancing the OPV device performances from a chemical view point of designing a new compound.

Influence of the perfluoroalkyl chain length in buckminsterfullerene derivatives for the field-effect transistor performances

Series of [60]fulleropyrrolidine derivatives containing perfluoroalkyl chains of different lengths linked to a phenyl group through a pyrrolidine ring have been successfully designed and synthesized. These compounds exhibited field-effect electron mobility with values ranging from 10−3 to 10−2cm2V−1s−1 depending on the length of the alkyl chain at the N-1 position of the pyrrolidine ring and perfluoroalkyl chain. A device operation study was also conducted under ambient conditions, revealing that the fluoroalkyl chains effectively induce air durability of FET devices. Our results thus suggest the short perfluoroalkyl groups can be selected as an alternative substituent group of the [60]fullerene for solution processable n-channel OFET material.

Evidence of charge-remote fragmentation in protonated [60]fulleropyrrolidine multi-adducts

[60]fulleropyrrolidine derivatives (Prato adducts of C60) with up to three ligands were protonated by electrospray ionization (ESI) and the collision-induced dissociation (CID) behaviour of these ions was studied with a quadrupole ion trap mass spectrometer. The systems under investigation showed distinctly different fragmentation behaviour for the neutral and the protonated ligands regarding both extent of fragmentation and pattern. This provided a means to distinguish reactions at the site of the charge from those occurring remote from it. In fact, evidence of charge-remote fragmentation (CRF) was obtained, with the neutral, charge-remote ligands showing efficient fragmentation and the protonated ligand largely resisting decomposition.

(Invited) Preparation of [60]Fulleropyrrolidines and Their Photovoltaic Applications

A series of fulleropyrrolidine derivatives (FPx, x=1-8) with alternating N-phenyl or N-methyl group were prepared as acceptors for polymer solar cells (PSCs) with the purpose of investigating the effect of N-substitutions on the photovoltaic properties of fullerene materials. More importantly, the morphology studies by means of atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and space charge limited current (SCLC) measurements revealed that FP1 with N-phenyl group possessed not only appropriate miscibility with P3HT but also high electron mobility, which may account for its optimal photovoltaic properties. In addition, we will also demonstrate our recent progress on the preparation of graphene-based composites and their applications as the electron or hole extraction layer (EEL or HEL) in PSCs. Figure 1

Efficiency enhancement from [60]fulleropyrrolidine-based polymer solar cells through N-substitution manipulation

A series of fulleropyrrolidine derivatives (FPx, x=1–8) with alternating N-phenyl or N-methyl group were prepared as acceptors for polymer solar cells (PSCs) with the purpose of investigating the effect of N-substitutions on the photovoltaic properties of fullerene materials. More importantly, the morphology studies by means of atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and space charge limited current (SCLC) measurements revealed that FP1 with N-phenyl group possessed not only appropriate miscibility with P3HT but also high electron mobility, which may account for its optimal photovoltaic properties.

Fulleropyrrolidine Derivatives with Benzophenone Moiety as Electron Acceptors in Thermally Stable Organic Photovoltaic Devices

Abstract Two fulleropyrrolidine derivatives with the benzophenone moiety were synthesized based on a molecular design that suppresses their crystallization. The organic photovoltaic devices using the fulleropyrrolidine derivatives showed higher thermal stability than the devices using [6,6]-phenyl C61-butyric acid methyl ester. Solid-state nuclear magnetic resonance studies revealed that the benzophenone moiety reduced the domain sizes of the fullerene derivatives in the bulk heterojunction.

Essential factors for control of the equilibrium in the reversible rearrangement of M₃N@I(h)-C₈₀ fulleropyrrolidines: exohedral functional groups versus endohedral metal clusters.

The effects of exohedral moieties and endohedral metal clusters on the isomerization of M3N@I(h)-C80 products from the Prato reaction through [1,5]-sigmatropic rearrangement were systematically investigated by using three types of fulleropyrrolidine derivatives and four different endohedral metal clusters. As a result, all types of derivatives provided the same ratios of the isomers for a given trimetallic nitride template (TNT) as the thermodynamic products, thus indicating that the size of the endohedral metal clusters inside C80 was the single essential factor in determining the equilibrium between the [6,6]-isomer (kinetic product) and the [5,6]-isomer. In all the derivatives, the [6,6]- and [5,6]-Prato adducts with larger metal clusters, such as Y3N and Gd3N, were equally stable, which is in good agreement with DFT calculations. The reaction rate of the rearrangement was dependent on both the substituent of exohedral functional groups and the endohedral metal-cluster size. Further DFT calculations and (13)C NMR spectroscopic studies were employed to rationalize the equilibrium in the rearrangement between the [6,6]- and [5,6]-fulleropyrrolidines.

The effect of thiophene substituents of fulleropyrrolidine acceptors on the performance of inverted organic solar cells

A series of tailored fulleropyrrolidine derivatives with thiophene substituents was synthesized and studied as electron acceptor materials in inverted organic bulk heterojunction (BHJ) solar cells. The study concentrated on seeking correlation between the molecular structure of the acceptor and its capability to form a photovoltaic BHJ film with the used electron donor material poly(3-hexylthiophene), P3HT. Atomic force and scanning electron microscopy imaging showed that the sensitivity of the BHJ morphology is tied to the molecular structure of the acceptor, which was further studied by photovoltaic characterization of the model solar cells. The photovoltaic performance clearly depended on the molecular structure of the fulleropyrrolidine substituents although there was only slight difference in the BHJ surface morphology. Fulleropyrrolidine derivatives with one or two thiophene units performed better as acceptor materials than those with three or four thiophene units. Additionally, hexyl side chains attached to the four thiophene unit increased the compatibility of a fulleropyrrolidine derivative with P3HT compared to a similar derivative without of the hexyl groups. The results provide new knowledge of the effect of the molecular structure of fulleropyrrolidine derivatives on the BHJ morphology in organic photovoltaics.