Premium
Structural elucidation of nitro‐substituted five‐membered aromatic heterocycles utilizing GIAO DFT calculations
Author(s) -
Katritzky Alan R.,
Akhmedov Novruz G.,
Doskocz Jacek,
Hall C. Dennis,
Akhmedova Rena G.,
Majumder Suman
Publication year - 2007
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1894
Subject(s) - chemistry , chemical shift , nitro , density functional theory , coupling constant , computational chemistry , carbon 13 nmr , aromaticity , atomic orbital , molecule , stereochemistry , organic chemistry , alkyl , physics , particle physics , quantum mechanics , electron
The GIAO (Gauge Including Atomic Orbitals) DFT (Density Functional Theory) method is applied at the B3LYP/6–31+G(d,p)//B3LYP/6–31+G(d), B3LYP/6–311++G(d,p)//B3LYP/6–31+G(d), B3LYP/6–311+G (2d,p)//B3LYP/6–31+G(d) and B3LYP/6–311++G(d,p)//B3LYP/6–311++G(d,p) levels of theory for the calculation of proton and carbon chemicals shifts and coupling constants for 25 nitro‐substituted five‐membered heterocycles. Difference (1D NOE) spectra in combination with long‐range gHMBC experiments were used as tools for the structural elucidation of nitro‐substituted five‐membered heterocycles. The assigned NMR data (chemical shifts and coupling constants) for all compounds were found to be in good agreement with theoretical calculations using the GIAO DFT method. The magnitudes of one‐bond ( 1 J CH ) and long‐range ( n J CH , n > 1) coupling constants were utilized for unambiguous differentiation between regioisomers of nitro‐substituted five‐membered heterocycles. Copyright © 2006 John Wiley & Sons, Ltd.