Abstract
The spectroscopic features and molecular structure of 5-fluoro-6-(4-methylpiperazin-1-yl)benzo[d]thiazol-2-amine (2-ABT) have been determined. Single-crystal X-ray analysis and vibrational spectroscopy have revealed the existence of 2-ABT in the amino tautomeric form in the solid state. Properties of 2-ABT in solution have been investigated using 1H and 13C NMR spectroscopy along with electronic absorption spectroscopy. The experimental data are complemented by DFT and TD-DFT calculations at the B3LYP/6–311 + g(2d,p) level. TD-DTF-predicted spectroscopic and structural properties for both amino and imino tautomers of 2-ABT are compared with the measured data; no strong evidence for the presence of the imino tautomer is found within the experimental data. Calculated energy differences between the tautomers strongly favour the amino tautomer over the other. Indeed, X-ray crystallography has unequivocally shown the amino tautomer which co-crystallized with one water molecule in the orthorhombic space group Pnna. Analysis of the crystal packing reveals an interesting structural motif which comprises an assemblage of the 2-ABT molecules through π···π stacking interactions. Furthermore, there exist hydrogen-bonding interactions involving the lattice solvent and the amino group along with the benzothiazole nitrogen atom.
| Original language | English |
|---|---|
| Pages (from-to) | 614-621 |
| Number of pages | 8 |
| Journal | Journal of Molecular Structure |
| Volume | 1176 |
| DOIs | |
| Publication status | Published - Jan 15 2019 |
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Keywords
- 2-aminobenzothiazole
- Amino-imino tautomer
- DFT calculations
- H-bonding interactions
- Single-crystal X-ray
ASJC Scopus subject areas
- Analytical Chemistry
- Spectroscopy
- Organic Chemistry
- Inorganic Chemistry
Cite this
Spectroscopic characterization, crystallographic elucidation and DFT investigation of 5-fluoro-6-(4-methylpiperazin-1-yl)benzo[d]thiazol-2-amine. / Al-Harthy, Thuraya S.; Shongwe, Musa; Husband, John; Stoll, Raphael; Merz, Klaus; Abdel-Jalil, Raid.
In: Journal of Molecular Structure, Vol. 1176, 15.01.2019, p. 614-621.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spectroscopic characterization, crystallographic elucidation and DFT investigation of 5-fluoro-6-(4-methylpiperazin-1-yl)benzo[d]thiazol-2-amine
AU - Al-Harthy, Thuraya S.
AU - Shongwe, Musa
AU - Husband, John
AU - Stoll, Raphael
AU - Merz, Klaus
AU - Abdel-Jalil, Raid
PY - 2019/1/15
Y1 - 2019/1/15
N2 - The spectroscopic features and molecular structure of 5-fluoro-6-(4-methylpiperazin-1-yl)benzo[d]thiazol-2-amine (2-ABT) have been determined. Single-crystal X-ray analysis and vibrational spectroscopy have revealed the existence of 2-ABT in the amino tautomeric form in the solid state. Properties of 2-ABT in solution have been investigated using 1H and 13C NMR spectroscopy along with electronic absorption spectroscopy. The experimental data are complemented by DFT and TD-DFT calculations at the B3LYP/6–311 + g(2d,p) level. TD-DTF-predicted spectroscopic and structural properties for both amino and imino tautomers of 2-ABT are compared with the measured data; no strong evidence for the presence of the imino tautomer is found within the experimental data. Calculated energy differences between the tautomers strongly favour the amino tautomer over the other. Indeed, X-ray crystallography has unequivocally shown the amino tautomer which co-crystallized with one water molecule in the orthorhombic space group Pnna. Analysis of the crystal packing reveals an interesting structural motif which comprises an assemblage of the 2-ABT molecules through π···π stacking interactions. Furthermore, there exist hydrogen-bonding interactions involving the lattice solvent and the amino group along with the benzothiazole nitrogen atom.
AB - The spectroscopic features and molecular structure of 5-fluoro-6-(4-methylpiperazin-1-yl)benzo[d]thiazol-2-amine (2-ABT) have been determined. Single-crystal X-ray analysis and vibrational spectroscopy have revealed the existence of 2-ABT in the amino tautomeric form in the solid state. Properties of 2-ABT in solution have been investigated using 1H and 13C NMR spectroscopy along with electronic absorption spectroscopy. The experimental data are complemented by DFT and TD-DFT calculations at the B3LYP/6–311 + g(2d,p) level. TD-DTF-predicted spectroscopic and structural properties for both amino and imino tautomers of 2-ABT are compared with the measured data; no strong evidence for the presence of the imino tautomer is found within the experimental data. Calculated energy differences between the tautomers strongly favour the amino tautomer over the other. Indeed, X-ray crystallography has unequivocally shown the amino tautomer which co-crystallized with one water molecule in the orthorhombic space group Pnna. Analysis of the crystal packing reveals an interesting structural motif which comprises an assemblage of the 2-ABT molecules through π···π stacking interactions. Furthermore, there exist hydrogen-bonding interactions involving the lattice solvent and the amino group along with the benzothiazole nitrogen atom.
KW - 2-aminobenzothiazole
KW - Amino-imino tautomer
KW - DFT calculations
KW - H-bonding interactions
KW - Single-crystal X-ray
UR - http://www.scopus.com/inward/record.url?scp=85054855531&partnerID=8YFLogxK
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U2 - 10.1016/j.molstruc.2018.08.080
DO - 10.1016/j.molstruc.2018.08.080
M3 - Article
VL - 1176
SP - 614
EP - 621
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
SN - 0022-2860
ER -