Crystal structure and Hirshfeld surface analysis of 5-acetyl-3-amino-6-methyl-N-phenyl-4-[(E)-2-phenylethenyl]thieno[2,3-b]pyridine-2-carboxamide

The asymmetric unit of the title molecule consists of four molecules that differ primarily in the orientations of the styryl and the N-phenylcarboxamido groups.


Structural commentary
The asymmetric unit of (I) contains four molecules (Fig. 1) of which one (molecule I) is represented in an ORTEP-style plot in Fig. 2. The conformational differences between molecules I, II, III and IV are highlighted in the overlay diagram shown in Fig. 3. The maximum r.m.s. deviation of the overlay between molecules I, II, III and IV is 0.498 Å . The conformations of the four molecules differ primarily in the varying orientations of the styryl and the N-phenylcarboxamido groups, as indicated by the torsion and dihedral angles collated in Tables 1 and 2. The orientations of the latter substituents are partially determined by the intramolecular N-HÁ Á ÁO hydrogen bond (Table 3 and Fig. 2). In each molecule, both the thiophene and pyridine rings are planar to within 0.0235 (11) Å (maximum r.m.s deviation = 0.0163 Å ) and 0.0197 (12) Å (maximum r.m.s deviation = 0.0125 Å ). Other bond lengths and angles are all in the expected ranges.

Supramolecular features
In the crystal, various hydrogen-bonding interactions are found (Table 3). The strongest stem from interactions between the amide NH group and the pyridine N atom of a neighbouring molecule (N3-H3AÁ Á ÁN4 i , N6-H6DÁ Á ÁN7 ii , N9-H9AÁ Á ÁN10 v and N12-H12AÁ Á ÁN1 vi ). Weaker C33-H33CÁ Á ÁO8 iii and C75-H75Á Á ÁS4 v interactions between a methyl group and an a carbonyl O atom, and between a phenyl CH group and a thiophene S atom, respectively, consolidate Molecule I with displacement ellipsoids for the non-hydrogen atoms drawn at the 30% probability level. The intramolecular N-HÁ Á ÁO hydrogen bond is depicted by a dashed line.

Figure 3
Overlay image of the four molecules (I, II, III and IV) in the asymmetric unit of the title compound. Table 1 Selected torsion angles ( ).

Figure 1
The four molecules (I, II, III and IV) in the asymmetric unit of (I).
the packing. Together with three sets of C-HÁ Á Á(ring) interactions, supramolecular layers parallel to the ac plane with a width corresponding to b/2 are formed (Figs. 4 and 5).

Hirshfeld surface analysis
For the four molecules I, II, III and IV, intermolecular interactions (Table 4) were quantified using Hirshfeld surface analysis and the associated two-dimensional fingerprint plots generated. The calculations and visualization were carried out using Crystal Explorer 17.5 (Turner et al., 2017). Fig. 6  Packing in the crystal of (I) viewed along the b axis direction. N-HÁ Á ÁO, C-HÁ Á ÁO, N-HÁ Á ÁN and C-HÁ Á ÁS hydrogen bonds are depicted, respectively, by dark blue, black, light blue and yellow dashed lines. The C-HÁ Á Á(ring) interactions are illustrated by green dashed lines.

Figure 5
Packing viewed along the c-axis direction with intermolecular interactions depicted as in Fig. 2.
contributions. The percentage contributions of other weak interactions are listed in Table 5. The fact that the same interactions result in different contributions to the Hirshfeld surface for molecules I, II, III and IV can be attributed to the different environments of each molecule in the crystalline state.

Figure 6
A view of the three-dimensional Hirshfeld surface for the four molecules (I, II, III and IV) in the asymmetric unit of the title compound, plotted over (a) d norm and (b) shape-index.
In the crystal of TACXED, mutual N-HÁ Á ÁO hydrogen bonds form dimers, which are then associated into chains parallel to the c axis through O-HÁ Á ÁN hydrogen bonds involving the solvent water molecule. In the crystal of MUZXOW, the bicyclic core of the compound is slightly folded [1.9 (1) ], while pairwise intermolecular N-HÁ Á ÁO hydrogen bonding forms dimers across centres of symmetry. In the crystal of XEBPIF, an intramolecular N-HÁ Á ÁO carbonyl hydrogen bond closes an S(6) ring. Supramolecular chains along [011] mediated by O-HÁ Á ÁN(pyridine) hydrogen bonds form in the crystal. A three-dimensional network is completed byinteractions occurring between the benzene ring and the two rings of the thieno[2,3-b]pyridine unit. In the crystal of AWETIH, molecules are linked by pairs of N-HÁ Á ÁO hydrogen bonds, forming inversion dimers with an R 2 2 (8) ring motif. Within the dimers, which stack along the a-axis direction, there is a weakinteraction involving inversionrelated thiophene rings. In the crystal of ULAROQ, the conformation of the title molecule is partially determined by an intramolecular N-HÁ Á ÁO hydrogen bond, forming an S(6) loop, and an N-HÁ Á Á interaction involving the centroid of the 4-chlorophenyl ring. In the crystal, molecules are linked by pairs of N-HÁ Á ÁO hydrogen bonds, forming inversion dimers with an R 2 2 (20) ring motif. In the crystal of GOLDUH, the amino and carbonyl groups are nearly coplanar with the heterocyclic ring system. There are two N-HÁ Á ÁO hydrogenbonding interactions involving the same N-H donor set and two different acceptors, one in an intramolecular bond helping to fix the molecular conformation and the other defining a dimeric structure around the symmetry centre at (0, 1 2 , 1 2 ). In the crystal of QOLPEN, molecules are linked into a zigzag sheet propagating along the b-axis direction by intermolecular N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds. WUVZES crystallizes with two molecules in the asymmetric unit. The crystal structure is stabilized by intermolecular and intramolecular C-HÁ Á ÁO hydrogen bonds. The asymmetric unit of NEQSUA likewise comprises two molecules, which differ primarily in the orientations of the acetyl and p-anisyl substituents. In the crystal, N-HÁ Á ÁO hydrogen bonds form chains extending parallel to (110). The asymmetric unit of the molecular salt RUTRUV comprises two cations and two anions. Each cation features an intramolecular N-HÁ Á ÁO hydrogen bond, which closes an S(6) ring; in each case the hydropyridine ring adopts a half-chair conformation. In the crystal, O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds link the components into [100] chains.
Numerous C-HÁ Á ÁO interactions cross-link the chains into a three-dimensional network.