Solvated and solvent-free forms ofN,N′-dithiodiphthalimide

Abstract

N,N'-Dithiodiphthalimide, C16H8N2O4S2, crystallizes from ethyl acetate with two independent molecules in the asymmetric unit, in which the N-S-S-N torsion angles are -83.59 (19) and 92.9 (2) degrees. The molecules are linked by C-H...O hydrogen bonds and aromatic pi-pi-stacking interactions into a three-dimensional framework. When crystallized from either dichloromethane or ethanol, solvates are formed in which the molecules of the title compound lie across twofold rotation axes in space group C2/c, with N-S-S-N torsion angles of 93.54 (7) and 96.14 (11) degrees. There are no hydrogen bonds in these solvates, but the molecules are linked by aromatic pi-pi-stacking interactions into chains, between which there are continuous channels. Disordered solvent molecules occupy these channels, which account for ca 20% of the unit-cell volume.

Polymorphs and pseudopolymorphs of N,N′-dithiobisphthalimide

“…Here we report a number of further polymorphs and pseudopolymorphs of (I) which, taken together with those reported earlier (Skakle et al, 2001), appear to fall into several distinct groups or families (Table 1): solvent-free polymorphs, solvates where the molecules of (I) and the solvent are linked by CÐHÁ Á ÁO hydrogen bonds; and three types of solvate where the solvent molecules are not hydrogen bonded to the framework formed by the molecules of (I): those where the solvent molecules are in isolated cavities, channel polymorphs in which localized solvent molecules in the channels are readily re®nable, and channel polymorphs analogous to (2) and (3) in which the solvent molecules are disordered and/or mobile within the channels (non-localized solvent molecules).…”

“…Polymorph (1) of (I) crystallizes from a solution in ethyl acetate with Z H = 2 in space group P2 1 /c (Skakle et al, 2001). In this solvent-free polymorph, the molecules are linked by CÐ HÁ Á ÁO hydrogen bonds into centrosymmetric aggregates containing four molecules, two of each type, and these fourmolecule aggregates are further linked by aromatic %Á Á Á% stacking interactions and by weak CÐHÁ Á ÁO hydrogen bonds to form a continuous three-dimensional framework.…”

“…We recently reported (Skakle et al, 2001) two distinct crystalline forms of N,N H -dithiobisphthalimide, C 16 H 8 N 2 O 4 S 2 (I). When crystallized from ethyl acetate, (I) gave a solvent-free polymorph (1) in which the molecules were linked into a three-dimensional framework by a combination of CÐHÁ Á ÁO hydrogen bonds and aromatic %Á Á Á% stacking interactions.…”

Crystal structure of 4-methyl-5-(5-{[5-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-4-phenyl-4H-1,2,4-triazol-3-yl}disulfanyl]-4-phenyl-4H-1,2,4-triazol-3-yl)-2-phenyl-1,3-thiazol acetonitrile, (C36H26N8S4XC2H3N)

“…The torsion angle ¿C1-S1-S2-C19 is 68.7(2)°, indicating that the conformation in along the SI-S2 bond is approximately gauche (synclinal) [15]. It seems that in this conformer electrostatic repulsive and steric interactions are in minimum limit in the presence of acetonitrile molecule in the crystal packing.…”

“…Melting points were measured on an Electrothermal 9100 apparatus and are uncorrected. Elemental analyses were performed using a Heraeus CHN-O-Rapid analyzer.show clearly that the four rings do not share a common plane, and probably it is the result of electrostatic repulsive and steric interactions [13][14][15]. The torsion angle ¿C1-S1-S2-C19 is 68.7(2)°, indicating that the conformation in along the SI-S2 bond is approximately gauche (synclinal) [15].…”