Zusammenfassung
The crystal and molecular structure of three derivatives of carbonyl 2-substituted pyrroles was determined by the single crystal X-ray diffraction. There are 2,2-dichloro-1-(1-methyl-1H-pyrrol-2-yl)ethan-1-one (I), 2-chloro-1-(1H-pyrrol-2-yl)ethan-1-one (II) and methyl 1H-pyrrole-2-carboxylate (III). All compounds crystallize with one molecule in the asymmetric unit in P2(1)2(1)2(1) for I and II, ...
Zusammenfassung
The crystal and molecular structure of three derivatives of carbonyl 2-substituted pyrroles was determined by the single crystal X-ray diffraction. There are 2,2-dichloro-1-(1-methyl-1H-pyrrol-2-yl)ethan-1-one (I), 2-chloro-1-(1H-pyrrol-2-yl)ethan-1-one (II) and methyl 1H-pyrrole-2-carboxylate (III). All compounds crystallize with one molecule in the asymmetric unit in P2(1)2(1)2(1) for I and II, and P2(1)/c group for III. Despite the similar structures of the investigated compounds, the hydrogen bonds formed in their crystal structures adopt different H-bond motifs. In structure I, the dimers R-1(2)(5) and R-2(1)(7) form a chain along the b-axis, while in structures II and III, chain C(5) structural motifs are formed. The single point calculations at a omega B97XD/6-311++G(d,p) level of theory indicate that systems with N-HMIDLINE HORIZONTAL ELLIPSISO bonds have greater interaction energies (are more stable) compared with systems featuring C-HMIDLINE HORIZONTAL ELLIPSISO/Cl bonds. A descriptive Hirshfeld analysis showed that the greatest differences are visible for the HMIDLINE HORIZONTAL ELLIPSISH interactions. These HMIDLINE HORIZONTAL ELLIPSISH interactions predominate in structure III, accounting for 45% of the intermolecular interactions, while in structures I and II, they account for only 25%. Although compounds I-II contain Cl-atoms, the percentage of ClMIDLINE HORIZONTAL ELLIPSISCl interactions is rather low. In structure with two Cl-atoms (I), the contribution of the ClMIDLINE HORIZONTAL ELLIPSISCl contacts is 8.7% and for II, the contribution accounts for only 0.4% of the interactions.