6,8-Di­bromo-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₄Br₂O₃, the atoms of the 6,8-di­bromo­chromone unit are essentially coplanar [largest deviation from the mean planes = 0.1109 (3) Å] and the formyl group is twisted slightly with respect to the attached ring [C—C—C—O torsion angles = 11.5 (4) and −168.9 (3)°]. In the crystal, mol­ecules are linked to each other through halogen bonds [Br...O = 3.118 (2) Å, C—Br...O = 162.37 (8) and C=O...Br = 140.20 (15)°]. The molecules are further assembled via π–π stacking interactions [centroid–centroid distance = 3.850 (2) Å].

3-Acetyl-2-fluoro-6H-benzo[c]chromen-6-one

The title compound, C₁₅H₉FO₃, was obtained in a one-pot synthesis by Suzuki-Miyaura cross-coupling and nucleophilic substitution reaction of 4'-chloro-2',5'-di­fluoro­aceto­phenone with o-(meth­oxy­carbon­yl)phenyl­boronic acid. The asymmetric unit contains two crystallographically independent mol­ecules related by a non-crystallographic inversion centre. There are face-to-face stacking inter­actions between the aromatic rings of the benzoate and aceto­phenone units of the symmetry-independent mol­ecules [centroid-centroid distances = 3.870 (3) and 3.986 (3) Å]. In the crystal, mol­ecules are further assembled via stacking inter­actions along the a-axis direction. One of the mol­ecules inter­acts with its inversion equivalent [centroid-centroid distance between the aromatic rings of the benzoate and aceto­phenone units = 3.932 (3) Å], and the other inter­acts with its twofold axis equivalent [centroid-centroid distance between the aromatic rings of aceto­phenone units = 3.634 (3) Å].

(E)-3,4,5-Trimeth­oxy-N′-[(4-oxo-4H-chromen-3-yl)methyl­idene]benzo­hydrazide

In the title chromone-tethered benzohydrazide derivative, C₂₀H₁₈N₂O₆, the atoms of the E-3-(hydrazonometh­yl)-4H-chromen-4-one segment are essentially coplanar, the largest deviation being 0.065 (6) Å. The dihedral angle between this segment and the benzene ring of the tri­meth­oxy­benzene unit is 40.18 (10) Å. In the crystal, the mol­ecule is linked to its inverse-symmetry equivalent by pairs of N—H...O hydrogen bonds and C—H...π inter­actions. The –CH=N—NH– segment is stacked on the benzene ring of the chromone unit of a translation-related equivalent mol­ecule [centroid–centroid distance = 3.413 (6) Å].

6-Chloro-4-oxo-4H-chromene-3-carb­aldehyde

In the title compound, C₁₀H₅ClO₃, a chlorinated 3-formyl­chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0456 Å) with the largest deviation from the least-squares plane [0.1136 (16) Å] being found for the ring-bound carbonyl O atom. In the crystal, mol­ecules are linked through stacking inter­actions along the b axis [shortest centroid-centroid distance between the pyran and benzene rings = 3.4959 (15) Å].

Diethyl 4-oxo-4H-[1,4′-bi­quinoline]-3,3′-di­carboxyl­ate

In the title mol­ecule, C₂₄H₂₀N₂O₅, the quinoline and quinolinone moieties are practically perpendicular to each other, forming a dihedral angle of 89.06 (3)°. In the crystal, each moiety forms coplanar π-stacked couples with the respective inversion equivalents. The quinolinone moieties overlap with their benzene rings with a centroid–centroid separation of 3.641 (2) Å, whereas the quinoline moieties overlap with their pyridine rings with a separation of 3.592 (2) Å. The resulting supra­molecular chains propargate along [101].

6,8-Di­iodo-4-oxo-4H-chromene-3-carbalde­hyde

The title compound, C₁₀H₄I₂O₃, is an iodinated 3-formyl­chromone derivative, and the atoms are essentially coplanar [r.m.s. deviation = 0.049 Å, largest deviation from the least-squares plane = 0.111 (9) Å for the CH(=O) C atom]. In the crystal, mol­ecules are linked into a three-dimensional network through halogen bonds [I...O = 3.352 (5) and 3.405 (7) Å, C—I...O = 144.2 (3) and 154.5 (3)°, and C=O...I = 134.9 (6) and 146.0 (6)°], and π–π stacking inter­actions [centroid–centroid distance = 3.527 (6) Å].

6-Chloro-8-nitro-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₄ClNO₅, the non-H atoms of the 6-chloro­chromone unit are coplanar (r.m.s. deviation = 0.017 Å) with the largest deviation from the mean plane [0.031 (2) Å] being found for the C=O C atom. The nitro group (NO₂) is inclined to the chromone unit mean plane by 13.3 (2) °. The formyl group is also twisted with respect to the attached ring [C—C—C—O torsion angles = 10.8 (4) and −171.8 (2)°]. In the crystal, mol­ecules are linked via C-H...O hydrogen bonds forming slab-like networks lying parallel to (-301). The slabs are linked by π–π inter­actions involving the benzene rings of the chromone units [centroid–centroid distance = 3.770 (3) Å].

6-Bromo-4-oxo-4H-chromene-3-carb­alde­hyde

In the title compound, C₁₀H₅BrO₃, a brominated 3-formyl­chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0420 Å), with the largest deviation from its mean plane [0.109 (2) Å] being found for the ring-bound carbonyl O atom. In the crystal, mol­ecules are linked through halogen bonds [Br...O = 3.191 (2) Å, C—Br...O = 167.32 (10)° and C=O...Br = 168.4 (2)°] along [101]. Mol­ecules are assembled into layers parallel to (101) via π–π stacking inter­actions along the b axis [shortest centroid–centroid distance between the pyran and benzene rings = 3.495 (2) Å].

(E)-4-Methyl-N′-[(4-oxo-4H-chromen-3-yl)methyl­idene]benzohydrazide

In the title chromone-tethered benzohydrazide derivative, C₁₈H₁₄N₂O₃, the 4H-chromen-4-one and the –CH=N–NH–CO– units are each essentially planar, with the largest deviations from thei planes being 0.052 (2) and 0.003 (2) Å, respectively. The dihedral angles between the 4H-chromen-4-one and the –CH=N–NH–CO– units, the 4H-chromen-4-one unit and the benzene ring of the 4-tolyl group, and the benzene ring of the 4-tolyl group and the –CH=N–NH–CO– unit are 8.09 (7), 9.94 (5) and 17.97 (8)°, respectively. In the crystal, the mol­ecules form two types of centrosymmetric dimers: one by N—H...O hydrogen bonds and the other by π–π stacking inter­actions between the 4H-chromen-4-one unit and the 4-tolyl group [centroid–centroid distance = 3.641 (5) Å]. These dimers form one-dimensional assemblies extending along the a-axis direction. Additional π–π stacking inter­actions between two 4H-chromen-4-one units [centroid–centroid distance = 3.591 (5) Å] and two 4-tolyl groups [centroid–centroid distance = 3.792 (5) Å] organize the mol­ecules into a three-dimensional network.

6-Fluoro-4-oxo-4H-chromene-3-carbalde­hyde

In the title compound, C₁₀H₅FO₃, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0071 Å), with the largest deviation from the mean plane [0.0203 (15) Å] being found for the ring C atom in the 2-position. In the crystal, mol­ecules are linked into a three-dimensional architecture via C—H...O hydrogen bonds and π–π stacking inter­actions between the chromone units along the a-axis direction [centroid–centroid distance between the benzene and pyran rings = 3.707 (2) Å].

Diethyl 7,7′-di­chloro-4-oxo-4H-[1,4′-bi­quinoline]-3,3′-di­carboxyl­ate

In the title compound, C₂₄H₁₈Cl₂N₂O₅, the quinoline and quinolinone moieties are nearly perpendicular to each other, forming a dihedral angle of 82.36 (3)°. In the crystal, mol­ecules form a halogen bond between a Cl atom of a quinolinone moiety and the N atom of the quinoline moiety of the inversion equivalent [Cl...N = 3.106 (3) Å]. The mol­ecules also form two kinds of C—H...O hydrogen-bonded centrosymmetric inversion dimers, making chains along the c-axis direction which are further inter­linked by the halogen bonds into layers parallel to the bc plane.

Ethyl 8-meth­oxy-4-oxo-1,4-di­hydro­quinoline-3-carboxyl­ate

In the title compound, C₁₃H₁₃NO₄, the asymmetric unit contains four independent mol­ecules, each exhibiting an intra­molecular N—H...O hydrogen bond. The ethyl group in one of the four mol­ecules is disordered, with a refined occupancy ratio of 0.295 (16):0.705 (16). A face-to-face stacking inter­action is found between the benzene rings of the quinoline units of two of the mol­ecules [centroid–centroid distance = 3.541 (2) Å], which are sandwiched by the other two mol­ecules through N—H...O hydrogen bonding. In the crystal, the sandwiched mol­ecules are assembled via stacking inter­actions along the b-axis direction with their translation-symmetry equivalents [centroid–centroid distance = 3.529 (2) Å], and are further linked through N—H...O hydrogen bonding. The other two mol­ecules are linked via stacking inter­actions with their inversion-symmetry equivalents [centroid–centroid distances = 3.512 (3) and 3.716 (4) Å] and via N—H...O hydrogen bonding.

8-Chloro-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₅ClO₃, a chlorinated 3-formyl­chromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.032 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.0598 (14) Å] being for a pyran-ring C atom. In the crystal, mol­ecules are linked through stacking inter­actions along the b axis [shortest centroid-centroid distance between the pyran and benzene rings = 3.566 (2) Å].

6-Iodo-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₅IO₃, an iodinated 3-formyl­chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0259 Å), with the largest deviation from the least-squares plane [0.056 (5) Å] being found for the formyl O atom. In the crystal, mol­ecules are linked through I...O halogen bonds [I...O = 3.245 (4) Å, C—I...O = 165.95 (13) and C=O...I = 169.7 (4)°] along [101]. The supra­molecular chains are assembled into layers via π–π stacking inter­actions along the b axis [shortest centroid–centroid distance between the pyran and benzene rings = 3.558 (3) Å].

8-Fluoro-4-oxo-4H-chromene-3-carbalde­hyde

In the title compound, C₁₀H₅FO₃, the non-H atoms of the 8-fluoro­chromone unit are essentially coplanar (r.m.s. deviation = 0.0259 Å), with a largest deviation from the mean plane of 0.0660 (12) Å for the chromone carbonyl O atom. The formyl group is twisted with respect to the attached ring [C—C—C—O torsion angles = −11.00 (19) and 170.81 (11)°]. In the crystal, mol­ecules are linked via weak C—H...O hydrogen bonds along the a axis and [-101], forming corrugated layers parallel to (010). In addition, π–π stacking inter­actions [centroid–centroid distance between the planes of the pyran and benzene rings = 3.519 (2) Å] are observed between these layers.

(E)-4-Meth­oxy-N′-[(6-methyl-4-oxo-4H-chromen-3-yl)methyl­idene]benzo­hydrazide monohydrate

In the title hydrate, C₁₉H₁₆N₂O₄·H₂O, the 4H-chromen-4-one segment is slightly twisted, with a dihedral angle between the two six-membered rings of 3.30 (5)°. The dihedral angles between the plane of the pyran­one ring and the hydrazide plane and between the planes of the pyran­one ring and the benzene ring of the p-meth­oxy­benzene unit are 26.69 (4) and 2.23 (3)°, respectively. The mol­ecule is connected to the solvent water mol­ecule by an N—H...O hydrogen bond. In the crystal, there are π–π stacking inter­actions between centrosymmetrically related pyran­one rings [centroid–centroid distance = 3.5394 (9) Å], as well as bridges formed by the water mol­ecules via O—H...O hydrogen bonds.

6-Chloro-7-methyl-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₁H₇ClO₃, a chlorinated and methyl­ated 3-formyl­chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0670 Å), with the largest deviation from the least-squares plane [0.2349 (17) Å] being for the pyran carbonyl O atom. In the crystal, mol­ecules are linked through π–π stacking inter­actions along the a axis [centroid–centroid distance between the pyran rings = 3.824 (6) Å] and two stacks are connected by type I halogen–halogen inter­actions between the Cl atoms [Cl...Cl = 3.397 (3) Å].

6-Chloro-7-fluoro-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₄ClFO₃, a chlorinated and fluorinated 3-formyl­chromone derivative, all atoms are essentially coplanar (r.m.s. = 0.0336 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.062 (2) Å] being for a benzene-ring C atom. In the crystal, mol­ecules are linked through stacking inter­actions [centroid–centroid distance between the benzene and pyran rings = 3.958 (3) Å and inter­planar distance = 3.259 (3) Å], C—H...O hydrogen bonds, and short C...O contacts [2.879 (3) Å]. Unsymmetrical halogen–halogen inter­actions between the Cl and F atoms [Cl...F = 3.049 (3) Å, C—Cl...F = 148.10 (9)° and C—F...Cl = 162.06 (13)°] are also formed, giving a meandering two-dimensional network along the a axis.

7-Chloro-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₅ClO₃, a chlorinated 3-formyl­chromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.0592 Å for all non-H atoms), with the largest deviation from the least-squares plane [0.1792 (19) Å] being for the chromone-ring carbonyl O atom. In the crystal, mol­ecules are linked through C—H...O hydrogen bonds to form tetrads, which are assembled by stacking inter­actions [centroid–centroid distance between the pyran rings = 3.823 (3) Å] and van der Waals contacts between the Cl atoms [Cl...Cl = 3.4483 (16) Å and C—Cl...Cl = 171.73 (7)°] into a three-dimensional architecture.

(E)-3,4,5-Trimeth­oxy-N′-[(6-meth­oxy-4-oxo-4H-chromen-3-yl)methyl­idene]benzohydrazide monohydrate

In the title chromone-tethered benzohydrazide derivative, C₂₁H₂₀N₂O₇·H₂O, the atoms of the 4H-chromen-4-one segment are essentially coplanar (r.m.s. deviation = 0.0073 Å) with the largest deviation from the mean plane [0.012 (3) Å] being found for the benzene C atom. The dihedral angles between the chromone segment and the hydrazide plane and between the chromone segment and the benzene ring of the tri­meth­oxy­benzene unit are 24.67 (9) and 41.28 (8) Å, respectively. The mol­ecule is connected to the solvent water mol­ecule by O—H...O hydrogen bonds and weak C—H...O inter­actions. Additional N—H...O inter­actions are observed and together they link the mol­ecules into chains forming a two-dimensional network along (011).

Crystal structure of 7-bromo-4-oxo-4H-chromene-3-carbaldehyde

In the title compound, C₁₀H₅BrO₃, a brominated 3-formyl­chromone derivative, all atoms are essentially coplanar (r.m.s. = 0.0631 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.215 (3) Å] being for the formyl O atom. In the crystal, mol­ecules are linked into tapes through C—H...O hydrogen bonds and these tapes are assembled by stacking inter­actions [centroid–centroid distance between the pyran rings = 3.858 (3) Å] to form supra­molecular layers that stack along the c axis.

Crystal structure of (3,5-dibromo-2-hy­droxyphenyl){1-[(naphthalen-1-yl)carbonyl]-1H-pyrazol-4-yl}methanone

In the title compound, C₂₁H₁₂Br₂N₂O₃, a 1,4-diaroyl pyrazole derivative, the dihedral angles between the naphthalene ring system and the pyrazole ring, the pyrazole and benzene rings, and the naphthalene ring system and benzene ring are 50.0 (2), 51.1 (2) and 1.34 (16)°, respectively. The phenolic proton forms an intra­molecular O—H...O hydrogen bond with the adjacent carbonyl O atom. In the crystal, mol­ecules are linked by C—H...O hydrogen bonds, forming inversion dimers. The dimers are linked by C—H...Br hydrogen bonds, forming double stranded chains along [01-1]. The chains are linked by π–π inter­actions between the pyrazole rings and between the naphthalene and benzene rings [centroid–centroid distances = 3.592 (4) and 3.632 (4) Å, respectively].