Ethyl 2-[(Z)-3-chloro­benzyl­idene]-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate

In the title compound, C23H19ClN2O3S, the central pyrimidine ring is significantly puckered, assuming almost a screw boat conformation. In addition to the usual inter­molecular C—H⋯O hydrogen bonding, short intra­molecular C—H⋯S contacts and π–π stacking inter­actions [centroid–centroid distance = 3.762 (2) Å] contribute to the crystal packing

12-(4-Chloro­phen­yl)-7-methyl-10-phenyl-3,4,5,6,8,10-hexa­aza­tricyclo­[7.3.0.02,6]dodeca-1(9),2,4,7,11-penta­ene

The 12 non-H atoms defining the triple-fused-ring system in the title compound, C19H13ClN6, are almost coplanar (r.m.s. deviation = 0.023 Å). The chloro-substituted ring is almost effectively coplanar with the central atoms [dihedral angle = 6.74 (13)°], but the N-bound benzene ring is not [dihedral angle = 54.38 (13)°]. In the crystal, supra­molecular chains along the a axis sustained by C—H⋯π and π–π [centroid–centroid distance between N4C and C4N five-membered rings = 3.484 (2) Å] stacking occur. A very long C—Cl⋯π contact is also seen

Ethyl 2-(2-acetoxy­benzyl­idene)-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-1,3-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate1

In the title mol­ecule, C25H22N2O5S, the atoms of the thia­zolopyrimidine ring system, with the exception of the phenyl-bearing C atom [deviation = 0.177 (2) Å], are essentially planar [r.m.s deviation = 0.100 (2) °] and the mean plane of these atoms forms dihedral angles of 89.86 (10) and 7.97 (8)° with the phenyl and benzene rings, respectively. In the crystal, co-operative C—H⋯O and C—H⋯π inter­actions lead to a supra­molecular chain along the a axis. These chains are connected via π–π inter­actions [centroid–centroid = 3.7523 (13) Å]

12-(4-Methoxy­phen­yl)-10-phenyl-3,4,5,6,8,10-hexa­azatricyclo­[7.3.0.02,6]dodeca-1(9),2,4,7,11-penta­ene

In the title compound, C19H14N6O, the fused 12-membered tetra­zolo/pyrimidine/pyrrole ring system is almost planar (r.m.s. deviation = 0.013 Å). The 4-methoxy­phenyl and phenyl substituents on the pyrrole ring are both twisted with respect to the fused-ring system [dihedral angles = 25.39 (18) and 36.42 (18)°, respectively]. Intra­molecular C—H⋯N inter­actions occur. In the crystal, mol­ecules pack into layers in the ac plane and these are connected along the b axis via C—H⋯π and π–π [centroid–centroid separation = 3.608 (3) Å] inter­actions

4-{[(4Z)-5-Oxo-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl­idene]meth­yl}phenyl acetate

The title mol­ecule, C18H13NO4, shows a dihedral angle between the terminal acetyl group (r.m.s. deviation = 0.0081 Å) and remaining non-H atoms (r.m.s. = 0.0734 Å) of 53.45 (7)°. The configuration about the central olefinic bond is Z and overall the mol­ecule has a U-shaped conformation. Supra­molecular chains along the b-axis direction are found in the crystal structure. These are stabilized by (C=O)⋯π(ring centroid of the 1,3-oxazole ring) inter­actions [3.370 (2) Å]

Crystal structure of 1-(4-methylphenyl)-3-(propan-2-ylideneamino)thiourea

In the title thiosemicarbazone, C11H15N3S, the p-tolyl-N—H and imino-N—H groups are anti and syn, respectively, to the central thione-S atom. This allows for the formation of an intramolecular p-tolyl-N—H...N(imino) hydrogen bond. The molecule is twisted with the dihedral angle between the p-tolyl ring and the non-hydrogen atoms of the N=CMe2 residue being 29.27 (8)°. The crystal packing features supramolecular layers lying in the bc plane whereby centrosymmetric aggregates sustained by eight-membered thioamide {...HNCS}2 synthons are linked by further N—H...S hydrogen bonds. Layers are connected via methyl-C—H...π interactions. The supramolecular aggregation was further investigated by an analysis of the Hirshfeld surface and comparison made to related structures

Bis[bis(N-2-hydroxyethyl,N-isopropyl-dithiocarbamato)mercury(II)]2: crystal structure and Hirshfeld surface analysis

The presence of both κ2-chelating and μ2,κ2-tridentate bridging dithiocarbamate ligands in centrosymmetric {Hg[S2CN(iPr)CH2CH2OH]2}2 (1) leads to globular aggregates that are linked into a three-dimensional architecture via hydroxyl-O–H···O(hydroxy) hydrogen bonding. The structure contrasts that of Hg[S2CN(CH2CH2OH)2]2 (2; this is a literature structure) in which square planar units are connected into supramolecular chains via Hg···S secondary bonding; chains are connected in the crystal structure by hydroxyl-O–H···O(hydroxy) hydrogen bonding. A Hirshfeld surface analysis on 1 and 2 reveal the influence of O–H···O and Hg···S interactions on the molecular packing as well as the distinctive interactions, such as C–H···S interactions in 1 and C–H···π (HgS2C) contacts in 2. A bibliographic survey shows the different structural motifs observed for 1 and 2 are complimented by an additional five motifs for binary mercury(II) dithiocarbamates revealing a fascinating structural diversity for this class of compound

Two dialkylammonium salts of 2-amino-4-nitrobenzoic acid: crystal structures and Hirshfeld surface analysis

The crystal structures of two ammonium salts of 2-amino-4-nitrobenzoic acid are described, namely dimethylazanium 2-amino-4-nitrobenzoate, C2H8N+·C7H5N2O4−, (I), and dibutylazanium 2-amino-4-nitrobenzoate, C8H20N+·C7H5N2O4−, (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxylate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-antiperiplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxylate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intramolecular amino-N—H...O(carboxylate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supramolecular chain by charge-assisted amine-N—H...O(carboxylate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N—H...O(carboxylate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N—O...π(arene) and methyl-C—H...O(nitro) interactions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N—H...O(carboxylate) hydrogen bonding. The formation of ammonium-N—H...O(carboxylate) hydrogen bonds, involving all ammonium-N—H and carboxylate O atoms leads to a three-dimensional architecture; additional C—H...O(nitro) interactions contribute to the packing. The Hirshfeld surface analysis confirms the importance of the hydrogen bonding in both crystal structures. Indeed, O...H/H...O interactions contribute nearly 50% to the entire Hirshfeld surface in (I)

Utilizing Hirshfeld surface calculations, non-covalent interaction (NCI) plots and the calculation of interaction energies in the analysis of molecular packing

The analysis of atom-to-atom and/or residue-to-residue contacts remains a favoured mode of analysing the molecular packing in crystals. In this contribution, additional tools are highlighted as methods for analysis in order to complement the ‘crystallographer’s tool’, PLATON [Spek (2009). Acta Cryst. D65, 148–155]. Thus, a brief outline of the procedures and what can be learned by using Crystal Explorer [Spackman & Jayatilaka (2009). CrystEngComm 11, 19–23] is presented. Attention is then directed towards evaluating the nature, i.e. attractive/weakly attractive/repulsive, of specific contacts employing NCIPLOT [Johnson et al. (2010). J. Am. Chem. Soc. 132, 6498–6506]. This is complemented by a discussion of the calculation of energy frameworks utilizing the latest version of Crystal Explorer. All the mentioned programs are free of charge and straightforward to use. More importantly, they complement each other to give a more complete picture of how molecules assemble in molecular crystals