http://scholar.google.com/citations?hl=en&user=95SvbM8AAAAJ
1.
Coluci, Vitor; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
A molecular dynamics study of the rotational dynamics and polymerization of C60 in C60-cubane crystals Journal Article
Em: MRS Proceedings, vol. 1130, pp. 1130–W06, 2008.
@article{coluci2008molecular,
title = {A molecular dynamics study of the rotational dynamics and polymerization of C60 in C60-cubane crystals},
author = {Coluci, Vitor and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7973166&fileId=S1946427400024088},
year = {2008},
date = {2008-01-01},
journal = {MRS Proceedings},
volume = {1130},
pages = {1130--W06},
publisher = {Cambridge University Press},
abstract = {Recently, heteromolecular crystals of fullerene C60 and cubane (C8H8) have been synthesized. For some temperatures the C60 molecules are free to rotate whereas cubanes behave like a static bearing in a so-called rotor-stator phases. In this work we report classical and tight-binding molecular dynamics simulations in order to investigate the rotor-stator dynamics and polymerization processes. Our results show that, for 200 K and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations within the timescale of our simulations, while C60 fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (< 1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (> 10 ps). Random copolymerization among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recently, heteromolecular crystals of fullerene C60 and cubane (C8H8) have been synthesized. For some temperatures the C60 molecules are free to rotate whereas cubanes behave like a static bearing in a so-called rotor-stator phases. In this work we report classical and tight-binding molecular dynamics simulations in order to investigate the rotor-stator dynamics and polymerization processes. Our results show that, for 200 K and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations within the timescale of our simulations, while C60 fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (< 1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (> 10 ps). Random copolymerization among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure.
2.
Coluci, Vitor R; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study Journal Article
Em: The Journal of Chemical Physics, vol. 129, não 6, pp. 064506, 2008.
@article{coluci2008rotational,
title = {Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study},
author = {Coluci, Vitor R and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jcp/129/6/10.1063/1.2965885},
year = {2008},
date = {2008-01-01},
journal = {The Journal of Chemical Physics},
volume = {129},
number = {6},
pages = {064506},
publisher = {AIP Publishing},
abstract = {We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.
3.
Konstantinova, Elena; Camilo Jr, Alexandre; Barone, Paulo MVB; Dantas, Socrates O; Galvao, Douglas S
Some electronic properties of saturated and unsaturated cubane oligomers using DFT-based calculations Journal Article
Em: Journal of Molecular Structure: THEOCHEM, vol. 868, não 1, pp. 37–41, 2008.
@article{konstantinova2008some,
title = {Some electronic properties of saturated and unsaturated cubane oligomers using DFT-based calculations},
author = {Konstantinova, Elena and Camilo Jr, Alexandre and Barone, Paulo MVB and Dantas, Socrates O and Galvao, Douglas S},
url = {http://www.sciencedirect.com/science/article/pii/S016612800800448X},
year = {2008},
date = {2008-01-01},
journal = {Journal of Molecular Structure: THEOCHEM},
volume = {868},
number = {1},
pages = {37--41},
publisher = {Elsevier},
abstract = {Cubanes and cubane-based molecular structures attract considerable interest as structural units which represent a new class of materials with remarkable properties. These structures are potentially useful for a variety of industrial applications and, for this reason, deserve detailed study. One of the options is to use cubane-based structures to synthesize a new class of conducting polymers with small energy band gap. In the present work we use the DFT-based methods to perform geometrical optimization and obtain some electronic properties for cubane, cubatriene, saturated and unsaturated oligomers containing different number of cubane and cubatriene building units. Our results indicate that the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) manifests a small decrease with the growing units number for saturated or unsaturated oligomers. This energy difference is strongly dependent on the presence of hydrogen atoms and is greater for unsaturated structures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cubanes and cubane-based molecular structures attract considerable interest as structural units which represent a new class of materials with remarkable properties. These structures are potentially useful for a variety of industrial applications and, for this reason, deserve detailed study. One of the options is to use cubane-based structures to synthesize a new class of conducting polymers with small energy band gap. In the present work we use the DFT-based methods to perform geometrical optimization and obtain some electronic properties for cubane, cubatriene, saturated and unsaturated oligomers containing different number of cubane and cubatriene building units. Our results indicate that the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) manifests a small decrease with the growing units number for saturated or unsaturated oligomers. This energy difference is strongly dependent on the presence of hydrogen atoms and is greater for unsaturated structures.
2008
3.
Coluci, Vitor; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
A molecular dynamics study of the rotational dynamics and polymerization of C60 in C60-cubane crystals Journal Article
Em: MRS Proceedings, vol. 1130, pp. 1130–W06, 2008.
Resumo | Links | BibTeX | Tags: Cubanes, Molecular Dynamics, Molecular Machines, Rotor-Stator
@article{coluci2008molecular,
title = {A molecular dynamics study of the rotational dynamics and polymerization of C60 in C60-cubane crystals},
author = {Coluci, Vitor and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7973166&fileId=S1946427400024088},
year = {2008},
date = {2008-01-01},
journal = {MRS Proceedings},
volume = {1130},
pages = {1130--W06},
publisher = {Cambridge University Press},
abstract = {Recently, heteromolecular crystals of fullerene C60 and cubane (C8H8) have been synthesized. For some temperatures the C60 molecules are free to rotate whereas cubanes behave like a static bearing in a so-called rotor-stator phases. In this work we report classical and tight-binding molecular dynamics simulations in order to investigate the rotor-stator dynamics and polymerization processes. Our results show that, for 200 K and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations within the timescale of our simulations, while C60 fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (< 1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (> 10 ps). Random copolymerization among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure.},
keywords = {Cubanes, Molecular Dynamics, Molecular Machines, Rotor-Stator},
pubstate = {published},
tppubtype = {article}
}
Recently, heteromolecular crystals of fullerene C60 and cubane (C8H8) have been synthesized. For some temperatures the C60 molecules are free to rotate whereas cubanes behave like a static bearing in a so-called rotor-stator phases. In this work we report classical and tight-binding molecular dynamics simulations in order to investigate the rotor-stator dynamics and polymerization processes. Our results show that, for 200 K and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations within the timescale of our simulations, while C60 fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (< 1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (> 10 ps). Random copolymerization among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure.
2.
Coluci, Vitor R; Sato, Fernando; Braga, Scheila F; Skaf, Munir S; Galvao, Douglas S
Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study Journal Article
Em: The Journal of Chemical Physics, vol. 129, não 6, pp. 064506, 2008.
Resumo | Links | BibTeX | Tags: C60, C70, Cubanes, Fullerenes, Molecular Dynamics, Rotor-Stator
@article{coluci2008rotational,
title = {Rotational dynamics and polymerization of C60 in C60-cubane crystals: A molecular dynamics study},
author = {Coluci, Vitor R and Sato, Fernando and Braga, Scheila F and Skaf, Munir S and Galvao, Douglas S},
url = {http://scitation.aip.org/content/aip/journal/jcp/129/6/10.1063/1.2965885},
year = {2008},
date = {2008-01-01},
journal = {The Journal of Chemical Physics},
volume = {129},
number = {6},
pages = {064506},
publisher = {AIP Publishing},
abstract = {We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.},
keywords = {C60, C70, Cubanes, Fullerenes, Molecular Dynamics, Rotor-Stator},
pubstate = {published},
tppubtype = {article}
}
We report classical and tight-binding molecular dynamics simulations of the C60fullerene and cubane molecular crystal in order to investigate the intermolecular dynamics and polymerization processes. Our results show that, for 200 and 400 K, cubane molecules remain basically fixed, presenting only thermal vibrations, while C60fullerenes show rotational motions. Fullerenes perform “free” rotational motions at short times (≲1 ps), small amplitude hindered rotational motions (librations) at intermediate times, and rotational diffusive dynamics at long times (≳10 ps). The mechanisms underlying these dynamics are presented. Random copolymerizations among cubanes and fullerenes were observed when temperature is increased, leading to the formation of a disordered structure. Changes in the radial distribution function and electronic density of states indicate the coexistence of amorphous and crystalline phases. The different conformational phases that cubanes and fullerenes undergo during the copolymerization process are discussed.
1.
Konstantinova, Elena; Camilo Jr, Alexandre; Barone, Paulo MVB; Dantas, Socrates O; Galvao, Douglas S
Some electronic properties of saturated and unsaturated cubane oligomers using DFT-based calculations Journal Article
Em: Journal of Molecular Structure: THEOCHEM, vol. 868, não 1, pp. 37–41, 2008.
Resumo | Links | BibTeX | Tags: Cubanes, DFT, Polymer
@article{konstantinova2008some,
title = {Some electronic properties of saturated and unsaturated cubane oligomers using DFT-based calculations},
author = {Konstantinova, Elena and Camilo Jr, Alexandre and Barone, Paulo MVB and Dantas, Socrates O and Galvao, Douglas S},
url = {http://www.sciencedirect.com/science/article/pii/S016612800800448X},
year = {2008},
date = {2008-01-01},
journal = {Journal of Molecular Structure: THEOCHEM},
volume = {868},
number = {1},
pages = {37--41},
publisher = {Elsevier},
abstract = {Cubanes and cubane-based molecular structures attract considerable interest as structural units which represent a new class of materials with remarkable properties. These structures are potentially useful for a variety of industrial applications and, for this reason, deserve detailed study. One of the options is to use cubane-based structures to synthesize a new class of conducting polymers with small energy band gap. In the present work we use the DFT-based methods to perform geometrical optimization and obtain some electronic properties for cubane, cubatriene, saturated and unsaturated oligomers containing different number of cubane and cubatriene building units. Our results indicate that the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) manifests a small decrease with the growing units number for saturated or unsaturated oligomers. This energy difference is strongly dependent on the presence of hydrogen atoms and is greater for unsaturated structures.},
keywords = {Cubanes, DFT, Polymer},
pubstate = {published},
tppubtype = {article}
}
Cubanes and cubane-based molecular structures attract considerable interest as structural units which represent a new class of materials with remarkable properties. These structures are potentially useful for a variety of industrial applications and, for this reason, deserve detailed study. One of the options is to use cubane-based structures to synthesize a new class of conducting polymers with small energy band gap. In the present work we use the DFT-based methods to perform geometrical optimization and obtain some electronic properties for cubane, cubatriene, saturated and unsaturated oligomers containing different number of cubane and cubatriene building units. Our results indicate that the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) manifests a small decrease with the growing units number for saturated or unsaturated oligomers. This energy difference is strongly dependent on the presence of hydrogen atoms and is greater for unsaturated structures.
