TY  - JOUR
A1  - Koch, Andreas
A1  - Stamboliyska, Bistra
A1  - Mikhova, Bozhana
A1  - Breznica-Selmani, Pranvera
A1  - Mladenovska, Kristina
A1  - Popovski, Emil
T1  - Calculations of C-13 NMR chemical shifts and F-C coupling constants of ciprofloxacin
JF  - Magnetic resonance in chemistry
N2  - Ciprofloxacin is a widely used fluoroquinolone antibiotic. In this work, a comprehensive evaluation of MP2 and DFT with different functionals and basis sets was carried out to select the most suitable level of theory for the study of the NMR properties of ciprofloxacin. Their relative predictive capabilities were evaluated comparing the theoretically predicted and experimental spectral data. Our computational results indicated that in contrast to the solid state, the molecule of ciprofloxacin does not exist as a zwitterion in gaseous state. The results of the calculations of the chemical shifts most close to the experimental were obtained with B3LYP/aug-cc-pVDZ. The F-C coupling constants were calculated systematically with different DFT methods and several basis sets. In general, the calculations of the coupling constants with the BHandH computational method including the applied in this work 6-311++G**, EPRII, and EPRIII basis sets showed a good reproducibility of the experimental values of the coupling constants.
KW  - C-13 chemical shifts
KW  - ciprofloxacin
KW  - DFT calculations
KW  - F-C coupling constants
KW  - NMR
Y1  - 2019
U6  - https://doi.org/10.1002/mrc.4827
SN  - 0749-1581
SN  - 1097-458X
VL  - 57
IS  - 4
SP  - 75
EP  - 84
PB  - Wiley
CY  - Hoboken
ER  -