On the structure and spectroscopic properties of bispidine, N, N′-dimethylbispidine and a bis-bispidine macrocycle

V. Galasso, K. Goto, Y. Miyahara, B. Kovač, L. Klasinc

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The equilibrium conformations of bispidine and its N, N′-dimethyl derivative were investigated with the ab initio MP2 formalism and the density functional theory (DFT) ansatz B3LYP. For bispidine, the chair-chair (cc) (exo, endo) is the most stable conformer. On the contrary, for its N, N′-dimethyl derivative, the energy difference between the cc and chair-boat (cb) conformers is small, allowing for conformational mobility of the bicyclo rings. For tetraaza-macrocycle with four nitrogen lone pair orbitals (LPOs) pointing into the molecular cavity, the C2h structure with stepped ethylene bridges is preferred over the twisted structure of D2 symmetry. Mono- and di-protonated forms of this base are characterized by intramolecular asymmetric hydrogen bonds. All the theoretical conformational predictions are consistent with the available experimental results. The NMR chemical shifts, calculated by the continuous set of gauge transformations (CSGT) formalism with the DFT/B3LYP method, are fairly consistent with NMR observation. The He(I) photoelectron (PE) spectra were measured and assigned by means of ab initio outer valence Green's function (OVGF) calculations. The predominance of the lowest energy conformation of bispidine and tetraaza-macrocycle is supported by the spectroscopic results. The conformational situation for N, N′-dimethyl-bispidine is more complex. Whereas its NMR spectrum indicates a predominance of the cc conformer in THF-d8 solution, the vibrational and PE spectra should be interpreted in terms of a mixture of the cc and cb conformers in the neat liquid and gas phase.

Original languageEnglish
Pages (from-to)229-240
Number of pages12
JournalChemical Physics
Volume277
Issue number3
DOIs
Publication statusPublished - Apr 1 2002

Fingerprint

seats
Nuclear magnetic resonance
Boats
Photoelectrons
Density functional theory
Conformations
Derivatives
Chemical shift
Green's function
Gages
boats
Hydrogen bonds
Nitrogen
Gases
nuclear magnetic resonance
photoelectrons
bispidine
density functional theory
formalism
Liquids

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

On the structure and spectroscopic properties of bispidine, N, N′-dimethylbispidine and a bis-bispidine macrocycle. / Galasso, V.; Goto, K.; Miyahara, Y.; Kovač, B.; Klasinc, L.

In: Chemical Physics, Vol. 277, No. 3, 01.04.2002, p. 229-240.

Research output: Contribution to journalArticle

Galasso, V. ; Goto, K. ; Miyahara, Y. ; Kovač, B. ; Klasinc, L. / On the structure and spectroscopic properties of bispidine, N, N′-dimethylbispidine and a bis-bispidine macrocycle. In: Chemical Physics. 2002 ; Vol. 277, No. 3. pp. 229-240.
@article{ac9233e226be4ef89b7d127758582c3b,
title = "On the structure and spectroscopic properties of bispidine, N, N′-dimethylbispidine and a bis-bispidine macrocycle",
abstract = "The equilibrium conformations of bispidine and its N, N′-dimethyl derivative were investigated with the ab initio MP2 formalism and the density functional theory (DFT) ansatz B3LYP. For bispidine, the chair-chair (cc) (exo, endo) is the most stable conformer. On the contrary, for its N, N′-dimethyl derivative, the energy difference between the cc and chair-boat (cb) conformers is small, allowing for conformational mobility of the bicyclo rings. For tetraaza-macrocycle with four nitrogen lone pair orbitals (LPOs) pointing into the molecular cavity, the C2h structure with stepped ethylene bridges is preferred over the twisted structure of D2 symmetry. Mono- and di-protonated forms of this base are characterized by intramolecular asymmetric hydrogen bonds. All the theoretical conformational predictions are consistent with the available experimental results. The NMR chemical shifts, calculated by the continuous set of gauge transformations (CSGT) formalism with the DFT/B3LYP method, are fairly consistent with NMR observation. The He(I) photoelectron (PE) spectra were measured and assigned by means of ab initio outer valence Green's function (OVGF) calculations. The predominance of the lowest energy conformation of bispidine and tetraaza-macrocycle is supported by the spectroscopic results. The conformational situation for N, N′-dimethyl-bispidine is more complex. Whereas its NMR spectrum indicates a predominance of the cc conformer in THF-d8 solution, the vibrational and PE spectra should be interpreted in terms of a mixture of the cc and cb conformers in the neat liquid and gas phase.",
author = "V. Galasso and K. Goto and Y. Miyahara and B. Kovač and L. Klasinc",
year = "2002",
month = "4",
day = "1",
doi = "10.1016/S0301-0104(02)00331-2",
language = "English",
volume = "277",
pages = "229--240",
journal = "Chemical Physics",
issn = "0301-0104",
publisher = "Elsevier",
number = "3",

}

TY - JOUR

T1 - On the structure and spectroscopic properties of bispidine, N, N′-dimethylbispidine and a bis-bispidine macrocycle

AU - Galasso, V.

AU - Goto, K.

AU - Miyahara, Y.

AU - Kovač, B.

AU - Klasinc, L.

PY - 2002/4/1

Y1 - 2002/4/1

N2 - The equilibrium conformations of bispidine and its N, N′-dimethyl derivative were investigated with the ab initio MP2 formalism and the density functional theory (DFT) ansatz B3LYP. For bispidine, the chair-chair (cc) (exo, endo) is the most stable conformer. On the contrary, for its N, N′-dimethyl derivative, the energy difference between the cc and chair-boat (cb) conformers is small, allowing for conformational mobility of the bicyclo rings. For tetraaza-macrocycle with four nitrogen lone pair orbitals (LPOs) pointing into the molecular cavity, the C2h structure with stepped ethylene bridges is preferred over the twisted structure of D2 symmetry. Mono- and di-protonated forms of this base are characterized by intramolecular asymmetric hydrogen bonds. All the theoretical conformational predictions are consistent with the available experimental results. The NMR chemical shifts, calculated by the continuous set of gauge transformations (CSGT) formalism with the DFT/B3LYP method, are fairly consistent with NMR observation. The He(I) photoelectron (PE) spectra were measured and assigned by means of ab initio outer valence Green's function (OVGF) calculations. The predominance of the lowest energy conformation of bispidine and tetraaza-macrocycle is supported by the spectroscopic results. The conformational situation for N, N′-dimethyl-bispidine is more complex. Whereas its NMR spectrum indicates a predominance of the cc conformer in THF-d8 solution, the vibrational and PE spectra should be interpreted in terms of a mixture of the cc and cb conformers in the neat liquid and gas phase.

AB - The equilibrium conformations of bispidine and its N, N′-dimethyl derivative were investigated with the ab initio MP2 formalism and the density functional theory (DFT) ansatz B3LYP. For bispidine, the chair-chair (cc) (exo, endo) is the most stable conformer. On the contrary, for its N, N′-dimethyl derivative, the energy difference between the cc and chair-boat (cb) conformers is small, allowing for conformational mobility of the bicyclo rings. For tetraaza-macrocycle with four nitrogen lone pair orbitals (LPOs) pointing into the molecular cavity, the C2h structure with stepped ethylene bridges is preferred over the twisted structure of D2 symmetry. Mono- and di-protonated forms of this base are characterized by intramolecular asymmetric hydrogen bonds. All the theoretical conformational predictions are consistent with the available experimental results. The NMR chemical shifts, calculated by the continuous set of gauge transformations (CSGT) formalism with the DFT/B3LYP method, are fairly consistent with NMR observation. The He(I) photoelectron (PE) spectra were measured and assigned by means of ab initio outer valence Green's function (OVGF) calculations. The predominance of the lowest energy conformation of bispidine and tetraaza-macrocycle is supported by the spectroscopic results. The conformational situation for N, N′-dimethyl-bispidine is more complex. Whereas its NMR spectrum indicates a predominance of the cc conformer in THF-d8 solution, the vibrational and PE spectra should be interpreted in terms of a mixture of the cc and cb conformers in the neat liquid and gas phase.

UR - http://www.scopus.com/inward/record.url?scp=0036534206&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036534206&partnerID=8YFLogxK

U2 - 10.1016/S0301-0104(02)00331-2

DO - 10.1016/S0301-0104(02)00331-2

M3 - Article

AN - SCOPUS:0036534206

VL - 277

SP - 229

EP - 240

JO - Chemical Physics

JF - Chemical Physics

SN - 0301-0104

IS - 3

ER -