Crystal structure of the 1:1 adduct of 2,3-diphenyl-3,4,5,6-tetrahydro-2H-1,3-thiazin-4-one with triphenyltin chloride

In the adduct resulting from the reaction of 2,3-diphenyl-3,4,5,6-tetrahydro-2H-1,3-thiazin-4-one with triphenyltin chloride, the three rings of the triphenyltin group are involved in intramolecular interactions of different types, and all the phenyl rings participate in intermolecular π–π interactions.


Structural commentary
The molecular structure obtained ( Fig. 1) is similar to that reported for (1) (Smith et al., 1995). It is a 1:1 complex, with the carbonyl oxygen in (3) bound to the tin atom. The tin atom is pentacoordinate with a distorted trigonal-bipyramidal geometry (Table 1), the apical axis being the O-Sn-Cl line. Chlorine and (3) are in the axial positions and the three phenyl groups are equatorial. The C-Sn, Cl-Sn, and C-O bond lengths are similar to those in (1).
The current crystal structure (4) exhibits an envelope conformation for the thiazine ring with the sulfur atom forming the flap, similar to (3) (Yennawar & Silverberg, 2014, 2015. The structure has a C-HÁ Á ÁO type interaction between the only oxygen atom (O1) and a phenyl carbon C18 of the same molecule. Extensive intra-and intermolecular ring interactions influence the structure of the molecule as well as the crystal packing. Both parallel-displaced and T-shaped interactions, analyzed using PLATON (Spek, 2009) have been observed and are discussed below in Section 3.

Supramolecular Features
The adduct has a thiazine ring (ring-1) and five phenyl rings (rings-2 and ring-3 attached at positions 2 and 3 of the thiazine and rings 4, 5 and 6 of the triphenyltin moiety). The intramolecular interactions between all six rings influence orientation of the phenyl rings and the intermolecular interactions of the five phenyl rings stabilize the crystal lattice (Fig. 2).
centroid of ring-3, resulting in a T-typering-4 Á Á Á ring-3 interaction. Ring-6 has T-type interactions with both (ring-2 and ring-3) phenyl rings of the thiazine with inter-centroid distances of 5.112 (1) with ring-3 and 5.954 (1) Å with ring-2. The C3 atom of the thiazine ring is 3.5235 (6) Å from the centroid of ring-5, resulting in a C-HÁ Á Á interaction. Thus all six rings, aromatic and non-aromatic, participate in influencing the structure of the molecule. Intermolecular interactions -The five phenyl rings interact extensively with the phenyl rings of the neighboring molecules in the lattice. Of the eight suchinteractions, one belongs to the parallel-displaced type and seven are of the T-type. In the parallel-displaced interaction, ring-3 and ring-5 of a molecule interact respectively with ring-5 and ring-3 of molecules on opposite sides, forming a continuous chain along the a-axis direction. The distance between the centroids of these partially overlapping rings is 3.8627 (7) Å and the dihedral angle is 2 between the ring planes. Seven T-type interactions stabilize the lattice further with centroid distances ranging from 5.1688 (9) to 5.8599 (10) Å and the dihedral angles of 69 to 89 . Rings 2, 5 and 6 participate in three interactions each, ring-4 in two and ring-3 in one. The intra-and intermolecular interactions are listed in Table 2.

Database Survey
The crystal structure of triphenyltin chloride has also been reported (Tse et al., 1986;Bokii et al., 1970).

Figure 2
The packing of the title compound (4).
tion was stirred. The contents of the 5 mL flask were transferred to the 10 mL flask dropwise by syringe over a period of 30 minutes. After two h of stirring, the stirrer was turned off. The solution was slightly hazy. After four days, the solution was transferred to a 50 mL round-bottom flask with acetone and concentrated under vacuum to a white solid. Recrystallization from ligroin produced (4) as a white powder (0.1086 g, 45%), m.p. 405-407 K. Crystals for X-ray crystallography were grown by slow evaporation from cyclohexane.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. Hydrogen atoms were placed geometrically to ride on the carbon atoms during refinement with C-H distances of 0.97 Å (>CH 2 ) and 0.93 Å (-CH arom ) and with U iso (H) = 1.2U eq (C).

Special details
Experimental. The data collection nominally covered a full sphere of reciprocal space by a combination of 4 sets of ω scans each set at different φ and/or 2θ angles and each scan (5 s exposure) covering −0.300° degrees in ω. The crystal to detector distance was 5.82 cm. Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.