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1.
《印度化学会志》2022,99(11):100769
Fullerene-C60 and its heteroatom decorated forms have been widely investigated as drug delivery vehicles and for sensor applications. Further, in the literature carboxylated or carboxylic derivatives of fullerenes have found a special place for biological applications due to their promising water-soluble properties. In the scope of this study, we examined the interaction between paracetamol (acetaminophen) which is a widely prescribed drug to manage acute and chronic pain conditions and C60, silicon doped fullerene (SiC59) and (1,2-methanofullerene C60)-61-carboxylic acid (C60-CH-COOH) using density functional theory calculations. Stability evaluations, electronic and structural properties were carried out by analyzing binding energies, frontier molecular orbitals and natural bond orbitals. It was found that silicon doping on the surface of C60 enhanced the adsorption strength of paracetamol and SiC59 is quite sensitive to the presence of paracetamol drug molecule. 相似文献
2.
Fullerenes have been of research interest and they have been particularly studied for their possible applications as drug delivery vehicles. In the present research, the optimized molecular geometries, electronic properties and the possible interaction mechanisms between C60, Si- or Al-doped C60 and 6-chloro-3-hydroxy-2-pyrazinecarboxamide were investigated using quantum mechanical calculations. The calculated binding energies to the Si- and Al-doped fullerenes suggest that doping of fullerene nanocage enhances the interaction mechanism and alters the chemical and electronic properties. The results and parameters found in this research reveal further insight into drug delivery systems. 相似文献
3.
Arpita Varadwaj Dr. Pradeep R. Varadwaj 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(48):15345-15360
Based on an experimental observation, it has been controversially suggested in a study (Kurotobi et al., Science 2011 , 33, 613) that a single molecule of water can completely be localized within the subnano‐space inside the fullerene C60 cage and, that neither the H atoms nor the O lone‐pairs are linked, either via hydrogen bonding or through dative bonding, with the interior C‐framework of the C60 cage. To resolve the controversy, electronic structure calculations were performed by using the density functional theory, together with the quantum theory of atoms in molecules, the natural population and bond orbital analyses, and the results were analyzed by using varieties of recommended diagnostics often used to interpret noncovalent interactions. The present results reveal that the mechanically entrapped H2O molecule is not electronically innocent of the presence of the cage; each H atom of H2O is weakly O? H???C60 bonded, whereas the O lone‐pairs are O???C60 bonded regardless of the conformations investigated. Exploration of various featured properties suggests that H2O@C60 may be regarded as a unique system composed of both inter‐ and intramolecular interactions. 相似文献
4.
In this study, the application of graphene quantum dots (GQDs) and doped GQDs as potential carriers for the delivery of isoniazid (Iso) drug has been investigated, using density functional theory (DFT) calculations. For this purpose, the hexa-peri-hexabenzocoronene (as a GQD model) and its BN-, BP-, AlN-, and AlP-doped (C36X3Y3H18 where X = B, Al and Y = N, P) forms were selected. Our results indicated that the adsorption energies of isoniazid on doped GQDs were more negative than that of pure GQD. Moreover, the calculations showed that adsorption of isoniazid on AlN- and AlP-doped GQDs was thermodynamically favorable. The dipole moments of BP-, AlN-, and AlP-doped GQDs were much greater (5.799, 1.860, and 3.312 D, respectively) than that of pristine GQD (0 D). The AlN-Iso and AlP-Iso complexes had small energy gaps, low chemical potentials, and low global hardnesses, which were appropriate for their attachments to the target site. The nature of interactions was analyzed by the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) analyses. Overall, the results confirmed that the AlN- and AlP-doped GQDs could be used as potential carriers for drug delivery application. 相似文献
5.
The interactions between the embedded atom X (X = Li, Na, K, Rb, Cs; F, Cl, Br, I) andC60 cage in the endohedral-form complexes (X@C60) are calculated and discussed according to molecular mechanics from the point of view of the bonding and non-bonding. It
is found from the computational results that for atoms with radii larger than Li’s, their locations with the minimum interaction
in (X@C60) are at the cage center, while atom Li has an off-center location with the minimum interaction deviation of ~0.05 nm, and
the cage-environment in C60 can be regarded as syhero-symmetry in the region with radiusr of ~0.2 nm. It is shown that the interaction between X and C60 cage is of non-bonding characteristic, and this non-bonding interaction is not purely electrostatic. The repulsion and dispersion
in non-bonding interactions should not be neglected, which make important contribution to the location with minimum interaction
of X, at center or off center. Some rules about the variations of interactions with atomic radii have been obtained.
Project supportt:d by the National Natural Science Foundation of China. 相似文献
6.
A systematic study of rare gas atoms encapsulated in small fullerenes using dispersion corrected density functional theory
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The most stable fullerene structures from C20 to C60 are chosen to study the energetics and geometrical consequences of encapsulating the rare gas elements He, Ne, or Ar inside the fullerene cage using dispersion corrected density functional theory. An exponential increase in stability is found with increasing number of carbon atoms. A similar exponential law is found for the volume expansion of the cage due to rare gas encapsulation with decreasing number of carbon atoms. We show that dispersion interactions become important with increasing size of the fullerene cage, where Van der Waals forces between the rare gas atom and the fullerene cage start to dominate over repulsive interactions. The smallest fullerenes where encapsulation of a rare gas element is energetically still favorable are He@C48, Ne@C52, and Ar@C58. While dispersion interactions follow the trend Ar > Ne > He inside C60 due to the trend in the rare gas dipole polarizabilities, repulsive forces become soon dominant with smaller cage size and we have a complete reversal for the energetics of rare gas encapsulation at C50. © 2014 Wiley Periodicals, Inc. 相似文献
7.
Density functional theory (DFT) calculations are performed for a representative set of low-energy structures of C60-n Si n heterofullerenes (n = 1, 2, 6, 12, 20, 24, 30) to investigate the effect of silicon doping on the electron structure of fullerene. The results show that chemical shielding (CS) parameters are so sensitive to the structural distortion made by outwardly relaxing silicon doped atoms from the fullerene surface which results in puckered Si-doped rings. As a result, the chemical shifts of the nearest carbon sites of silicon atoms considerably shift to downfield. Our survey shows that those first neighbors of silicon atoms which have minor 13C chemical shift belong to normal (un-puckered) rings. Meanwhile, the chemical shielding anisotropy (Δσ) parameter detects the effects of dopant so that Δσ values of the carbon atoms which are contributed to the Si–C bond are mainly larger than the others. Compensation between diatropic and paratropic ring currents lead to less negative NICS values at cage centers of Si-doped fullerenes than that of C60 except C58Si2-b and C54Si6-b in which more negative NICS values may be attributed to more spherical geometries of their carbon cages. 相似文献
8.
H. Kamiyama K. Ohno Y. Maruyama Y. Kawazoe Y. Nishina K. Shindo 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,26(Z1):291-293
Two dimensional band structure is calculated for a triangular lattice of C60 molecules by using a mixed-basis approach in which wave functions are expanded with not only plane waves but also 1s and 2p atomic orbitals of carbon atoms. The present analysis modeling a charge transfer from Si dimers of the Si (100) surface suggests the existence of a small Fermi-surface. The resulting partial charge distribution is consistent with the recent STM observation of specific stripes, the direction of which is parallel to that of the topmost double bond of C60, regardless of the intermolecular interaction. It is concluded that the orientation of C60 on the Si surface is mainly determined by the direction of dimer arrays and not by the interaction between C60 molecules.ACKNOWLEDGEMENT The authors are very grateful to the Institute for Supercomputing Research of RECRUIT Co. for the use of the NEC SX-2 supercomputer. Authors also thank IBM Japan and Japan IMSL Inc. for supporting them a good computer environment. 相似文献
9.
Y. Kitagawa Y. Nakanishi T. Saito K. Koizumi M. Shoji S. Yamada T. Kawakami M. Okumura K. Yamaguchi 《Polyhedron》2009,28(9-10):1750-1753
The magnetic interactions between two C60 anions are investigated by using unrestricted B3LYP (UB3LYP) calculations. Among four types of interactions, only one type of SOMO–SOMO interaction shows a week ferromagnetic interaction (Jab = 4.6 cm?1) whilst other interactions show week anti-ferromagnetic interactions. In order to explain a mechanism of the ferromagnetic and the anti-ferromagnetic interactions, a natural orbital (NO) analysis and a spin density analysis are carried out. The results of the analyses suggest that orbital orthogonality between SOMOs of each C60 anions is the origin of the ferromagnetic interaction. On the other hand, a spin polarization effect does not appear in a spin density map in the ferromagnetic coupling state. 相似文献
10.
Dr. Wonsang Koh Hye Sook Moon Prof. Seung Geol Lee Dr. Ji Ii Choi Prof. Seung Soon Jang 《Chemphyschem》2015,16(4):789-795
The mechanism of Li adsorption on a graphene–fullerene (graphene–C60) hybrid system has been investigated using density functional theory (DFT). The adsorption energy for Li atoms on the graphene–C60 hybrid system (?2.285 eV) is found to be higher than that on bare graphene (?1.375 eV), indicating that the Li adsorption on the former system is more stable than on the latter. This is attributed to the high affinity of Li atoms to C60 and the charge redistribution that occurs after graphene is mixed with C60. The electronic properties of the graphene–C60 system such as band structure, density of states, and charge distribution have been characterized as a function of the number of Li atoms adsorbed in comparison to those of the pure graphene and C60. Li adsorption is found to preferentially occur on the C60 side due to the high adsorption energy of Li on C60, which imparts a metallic character to the C60 in the graphene–C60 hybrid system. 相似文献
11.
Optimized molecular geometries and electronic structures are determined for neutral, positively charged, and negatively charged carbon and silicon clusters containing up to ten atoms. The effects of polarization functions and electron correlation are included in these claculations. Carbon clusters have linear or monocyclic ground state geometries whereas silicon clusters containing five or more atoms have three-dimensional ground state structures. Neutral C4, C6 and C8 all have linear and monocyclic isomers of comparable stability whereas the ionic forms appear to be generally more stable as linear geometrical arrangements. In the case of neutral and positively charged carbon clusters, the odd-numbered clusters are significantly more stable than the adjacent even-numbered clusters whereas the opposite order of stability occurs for the negative ions. This is due to the large values of the electron affinities of the linear forms of even-numbered clusters such as C4 and C6. The relative stabilities of silicon clusters does not change with the charge state of the clusters. 相似文献
12.
The interaction between C60 molecules with a graphite (0001) surface has been investigated by means of molecular dynamics simulations. The initial energies of the C60 molecules are 90 and 270 eV, respectively. An empirical model potential suggested by Takai et al. is used to describe the interaction between carbon atoms in the C60 molecule and between the atoms forming the graphite substrate. The interaction between the C60 atoms and the graphite atoms is modeled by a suitable Lennard-Jones potential. The resilience of scattered C60 molecules is observed and its energy distribution is in reasonable agreement with available experimental data, showing no significant dependence of the rebounding translational energy on the incident kinetic energy. The energy partition in the collision has been analyzed in detail and a two-step collision model speculated in the experiments has been discussed based on the simulation results. 相似文献
13.
Prof. Yanli Zeng Dr. Wenjie Wu Dr. Xiaoyan Li Prof. Shijun Zheng Prof. Lingpeng Meng 《Chemphyschem》2013,14(8):1591-1600
The influences of the Li???π interaction of C6H6???LiOH on the H???π interaction of C6H6???HOX (X=F, Cl, Br, I) and the X???π interaction of C6H6???XOH (X=Cl, Br, I) are investigated by means of full electronic second‐order Møller–Plesset perturbation theory calculations and “quantum theory of atoms in molecules” (QTAIM) studies. The binding energies, binding distances, infrared vibrational frequencies, and electron densities at the bond critical points (BCPs) of the hydrogen bonds and halogen bonds prove that the addition of the Li???π interaction to benzene weakens the H???π and X???π interactions. The influences of the Li???π interaction on H???π interactions are greater than those on X???π interactions; the influences of the H???π interactions on the Li???π interaction are greater than X???π interactions on Li???π interaction. The greater the influence of Li???π interaction on H/X???π interactions, the greater the influences of H/X???π interactions on Li???π interaction. QTAIM studies show that the intermolecular interactions of C6H6???HOX and C6H6???XOH are mainly of the π type. The electron densities at the BCPs of hydrogen bonds and halogen bonds decrease on going from bimolecular complexes to termolecular complexes, and the π‐electron densities at the BCPs show the same pattern. Natural bond orbital analyses show that the Li???π interaction reduces electron transfer from C6H6 to HOX and XOH. 相似文献
14.
Krit Suknuntha Vimon Tantishaiyakul Visit Vao‐Soongnern Youssef Espidel Terrence Cosgrove 《Journal of Polymer Science.Polymer Physics》2008,46(12):1258-1264
Blends of chitosan and poly(vinyl pyrrolidone) (PVP) have a high potential for use in various biomedical applications and in advanced drug‐delivery systems. Recently, the physical and chemical properties of these blends have been extensively characterized. However, the molecular interaction between these two polymers is not fully understood. In this study, the intermolecular interaction between chitosan and PVP was experimentally investigated using 13C cross‐polarization magic angle‐spinning nuclear magnetic resonance (13C CP/MAS NMR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). According to these experimental results, the interaction between the polymers takes place through the carbonyl group of PVP and either the OH? C6, OH? C3, or NH? C2 of chitosan. In an attempt to identify the interacting groups of these polymers, molecular modeling simulation was performed. Molecular simulation was able to clarify that the hydrogen atom of OH? C6 of chitosan was the most favorable site to form hydrogen bonding with the oxygen atom of C?O of PVP, followed by that of OH? C3, whereas that of NH? C2 was the weakest proton donor group. The nitrogen atom of PVP was not involved in the intermolecular interaction between these polymers. Furthermore, the interactions between these polymers are higher when PVP concentrations are lower, and interactions decrease with increasing amounts of PVP. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1258–1264, 2008 相似文献
15.
Arpita Varadwaj Helder M. Marques Pradeep R. Varadwaj 《Journal of computational chemistry》2019,40(20):1836-1860
The wide occurrence of halogen-centered noncovalent interactions in crystal growth and design prompted this study, which includes a mini review of recent advances in the field. Particular emphasis is placed on providing compelling theoretical evidence of the formation of these interactions between sites of positive electrostatic potential, as well as between sites of negative electrostatic potential, localized on the electrostatic surfaces of the bound fluorine atoms in a prototypical system, hexafluoropropylene (C3F6), upon its interaction with another same molecule to form (C3F6)2 dimers. The existence of σ- and π-hole interactions is shown for the stable dimers. Even so, weakly bound interactions locally responsible in holding the molecular fragments together cannot and should not be overlooked since they are partly responsible for determining the overall geometry of the crystal. The results of combined quantum theory of atoms in molecules, molecular electrostatic surface potential, and reduced density gradient noncovalent interaction analyses showed that these latter interactions do indeed play a role in the stability and growth of crystalline C3F6 itself and the (C3F6)2 dimers. A symmetry adapted perturbation theory energy decomposition analysis leads to the conclusion that a great majority of the (C3F6)2 dimers examined are the consequence of dispersion (and electrostatics), with nonnegligible contribution from polarization, which together competes with an exchange repulsion component to determine the equilibrium geometries. In a few structures of the (C3F6)2 dimer, the fluorine is found to serve as a six-center five-bond donor/acceptor, as found for carbon in other systems (Malischewski and Seppelt, Angew. Chem. Int. Ed. 2017, 56, 368). © 2019 Wiley Periodicals, Inc. 相似文献
16.
Electronic structure of superstoichiometric silicon carbide, ß-SiC x>1.0, was studied by the self-consistentab initio linearized “muffin-tin” orbital method. It is most likely that the formation of ß-SiC x>1.0 occurs by replacement of silicon atoms by carbon atoms rather than by insertion of carbon atoms into interstitial lattice sites. The C→Si replacement is accompanied by lattice compression (the equilibrium lattice parameter for a superstoichiometric phase of composition Si0.75C1.25 is ?2% smaller than for SiC). In the presence of superstoichiometric carbon the type of interaction between silicon and carbon atoms changes and additional bonds characteristic of diamond are formed. 相似文献
17.
18.
Noncovalent interactions of free-base phthalocyanine (H2Pc) with closed-cap armchair (5,5) and zigzag (10,0) single-walled carbon nanotubes (ANT and ZNT, respectively), as well as, for comparison, with C60 and C80(I h) fullerenes, whose hemispheres were used to close the ends of nanotube models, were studied theoretically by using one pure dispersion-corrected GGA functional (PBE with a long-range dispersion correction by Grimme, or PBE+D) and two hybrid meta exchange-correlation functionals (M05-2X and M06-2X). Strong complexation was observed in all four systems studied. The general trend found is that the interaction strength increases with the size (number of C atoms) of carbon nanocluster, that is, in the order of ZNT > ANT > C80 > C60. Depending on the DFT functional employed, the interaction strength decreased in the order of PBE+D > M06-2X > M05-2X. A common feature for the geometry of all four complexes considered, reproduced in all the calculations, is that H2Pc macrocycle undergoes strong distortion, which allows for increasing its contact surface with the nanotube sidewall or spherical fullerene, and therefore makes π-π interactions more efficient. 相似文献
19.
Fullerene (C60), the third carbon allotrope, has shown great potential in photoelectric materials and drug delivery. However, the low solubility of C60 in polar solvents, especially in water, is the major limiting factor for further applications. The use of ultrasound and amphiphilic block copolymers, poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP), helped to disperse C60 in acidic aqueous solutions. As characterized by dynamic light scattering, transmission electron microscopy, and UV-visible spectroscopy, the C60 colloids had a core-shell structure with C60 aggregated in the micellar cores. The photosensitized generation of singlet oxygen using C60-bound polymer micelle was confirmed by the iodide method. More importantly, C60 and metalloporphyrin complexes could be synthesized by the self-assembly between PEG-b-P4VP/C60 micelle and metalloporphyrin. The stability of metalloporphyrin increased in the presence of the PEG-b-P4VP/C60 micelle. This study provides a method for the solubilization of C60 with many potential applications in biomedicals and photovoltaics. 相似文献
20.
Y. Ito 《Journal of Radioanalytical and Nuclear Chemistry》2003,255(1):171-174
The positron density distributions in C60 and K6C60 have been evaluated using the positron lifetime and Doppler-broadening spectroscopy for the annihilation radiation.In C60, positrons are distributed in the interstitial sites between the C60 molecules,which has been demonstrated by measurements of the temperature dependence of the Doppler-broadening of the annihilation radiation. On the other hand, the positron density distribution must be greatly changed in K6C60, because positrons are repelled by Coulomb interactions by the positively charged K atoms. It has been observed that there is an extremely short lifetime and a small Doppler-broadening component for the positron annihilation in K6C60. This component is considered to reflect the positron annihilation inside a C60 molecule. 相似文献