Nucleus-Independent Chemical Shift Criterion for Aromaticity in Some of the Corannulene Derivatives as Carbon Nanostructure: Effect of Substituent Groups on Aromaticity

The dianions of tetraphenylsilole and tetraphenylgermole behave as aromatic species, as shown by the equalization of C-C bond lengths in these rings and by nucleus-independent chemical shift (NICS) calculations. Similarly, the dianions of 9-silafluorene and 9-germafluorene are aromatic. In the latter species, the heteroatom five-membered rings are more aromatic than the attached benzene rings. Also to be recognized as aromatically stabilized compounds are the stable unsaturated diiminocarbenes, diiminosilylenes, and diiminogermylenes. Evidence for the aromatic delocalization in these molecules comes from NMR, NICS calculations, Raman spectroscopy, isodesmic molecular orbital (MO) calculations, and calculated isomerization stabilization energies. From the presently available evidence, the aromaticity appears to alternate, with C > Ge > Si, going down group 14.

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Probing carbon micropore size distribution by nucleus independent chemical shift

Carbon ◽

10.1016/j.carbon.2014.06.031 ◽

2014 ◽

Vol 77 ◽

pp. 1132-1139 ◽

Cited By ~ 20

Author(s):

Yun-Zhao Xing ◽

Zhi-Xiang Luo ◽

Alfred Kleinhammes ◽

Yue Wu

Keyword(s):

Chemical Shift ◽

Size Distribution ◽

Micropore Size Distribution ◽

Nucleus Independent Chemical Shift ◽

Micropore Size ◽

Carbon Micropore

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A Valence Bond Study of the Bergman Cyclization: Geometric Features, Resonance Energy, and Nucleus-Independent Chemical Shift (NICS) Values

Chemistry - A European Journal ◽

10.1002/(sici)1521-3765(20000417)6:8<1446::aid-chem1446>3.0.co;2-i ◽

2000 ◽

Vol 6 (8) ◽

pp. 1446-1454 ◽

Cited By ~ 34

Author(s):

John Morrison Galbraith ◽

Peter R. Schreiner ◽

Nathan Harris ◽

Wu Wei ◽

Alexander Wittkopp ◽

...

Keyword(s):

Chemical Shift ◽

Valence Bond ◽

Resonance Energy ◽

Geometric Features ◽

Bergman Cyclization ◽

Nucleus Independent Chemical Shift

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Theoretical insights into the properties of the borazine… X- complexes (X- = H, F, Cl, CN, NC or NCO)

Journal of the Serbian Chemical Society ◽

10.2298/jsc0910105g ◽

2009 ◽

Vol 74 (10) ◽

pp. 1105-1111 ◽

Cited By ~ 1

Author(s):

Reza Ghiasi

Keyword(s):

Charge Transfer ◽

Chemical Shift ◽

Total Energy ◽

Ab Initio ◽

Intermolecular Interactions ◽

Natural Bond Orbital ◽

Nbo Analysis ◽

Interaction Energies ◽

Ab Initio Method ◽

Nucleus Independent Chemical Shift

The character of the NH ...X- (X- = H, F, Cl, CN, NC or NCO) interactions of borazine with anions was studied using ab initio method. The interaction energies were calculated at the B3LYP/6-311++G(d,p) level. The energetic and geometric characteristics of the complexes were compared. The 'atoms in molecules' methodology was used to analyze the electron density and to obtain atomic contributions to the total energy and charge of the systems. Natural bond orbital (NBO) analysis demonstrated the charge transfer in the study of the nature of the intermolecular interactions. The aromaticity of these compounds was predicted in light of the nucleus-independent chemical shift (NICS).

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