Symmetry-related Benzene Rings Research Articles

The crystal structures and Hirshfeld surface analysis of N',N'''-((1E,1'E)-{[methyl-enebis(-oxy)]bis-(6-bromo-3,1-phenyl-ene)}bis-(methan-ylyl-idene))bis-(isonicotinohydrazide) dihydrate and N',N'''-((1E,1'E)-{[butane-1,4-diylbis(-oxy)]bis-(2,1-phenyl-ene)}bis-(methan-ylyl-idene))bis-(isonicotino-hydrazide) [+ solvent

The title compounds, C27H20Br2N6O4·2H2O, (I), and C30H28N6O4·[+ solvent], (II), both crystallize with one half-mol-ecule in the asymmetric unit. The whole mol-ecule of (I) is generated by twofold rotation symmetry, with the twofold rotation axis bis-ecting the C atom of the -O-CH2-O- bridge. This results in a folded or U-shaped conformation of the mol-ecule. The whole mol-ecule of (II) is generated by inversion symmetry, with the central CH2-CH2 bond of the -O-(CH2)4-O- bridge being located about a center of inversion. This results in a step-like conformation of the mol-ecule. The central C(=O)N-N=C regions of the isonicotinohydrazide moieties in both compounds are planar and the configuration about the imine C=N bonds is E. In compound (I), the benzene and pyridine rings are inclined to each other by 37.60 (6)°. The two symmetry-related pyridine rings are inclined to each other by 74.24 (6)°, and the two symmetry-related benzene rings by 7.69 (6)°. In compound (II), the benzene and pyridine rings are inclined to each other by 25.56 (11)°. The symmetry-related pyridine rings are parallel, as are the two symmetry-related benzene rings. In the crystal of (I), a pair of water mol-ecules link the organic mol-ecules via Owater-H⋯O and Owater-H⋯N hydrogen bonds, forming chains along [001], and enclosing an R 4 2(8) and two R 1 2(5) ring motifs. The chains are linked by N-H⋯Npyridine hydrogen bonds, forming a supra-molecular framework. There are also a number of C-H⋯O hydrogen bonds, and C-H⋯π and offset π-π inter-actions [inter-planar distance = 3.294 (1) Å] present reinforcing the framework. In the crystal of (II), mol-ecules are linked by N-H⋯Npyridine hydrogen bonds, forming a supra-molecular framework. Here too there are also a number of C-H⋯O hydrogen bonds present, and a C-H⋯π inter-action, reinforcing the framework. For compound (II), a region of disordered electron density was corrected for using the SQUEEZE [Spek (2015 ▸). Acta Cryst. C71, 9-18] routine in PLATON. Their formula mass and unit-cell characteristics were not taken into account during refinement.

Crystal structure of 2-methyl-3-nitro-benzoic anhydride.

The title mol­ecule, C16H12N2O7, lies on a twofold rotation axis which bis­ects the central O atom. The dihedral angle between two symmetry-related benzene rings is 48.54 (9)°. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds which generate C(13) chains running parallel to [31-1].

Crystal structure of catena-poly[[tri-methyl-tin(IV)]-μ-2-(2-nitro-phen-yl)acetato-κ(2) O:O'

In the title one-dimensional coordination polymer, [Sn(CH3)3(C8H6NO4)]n, the SnIV atom is coordinated by three methyl C atoms and two carboxyl­ate O atoms (one symmetry generated), resulting in an almost regular SnC3O2 trigonal pyramid. The C atoms occupy the equatorial sites and the O atoms occupy the axial sites. In the ligand, the dihedral angles between the benzene ring and the pendant acetate and nitro groups are 57.7 (1) and 36.9 (3)°, respectively. The bridging ligand leads to [010] chains in the crystal, with adjacent metal atoms related by a 21 screw axis. A weak π–π inter­action exists between the centroids of symmetry-related benzene rings at a distance of 3.9131 (19) Å.

Bis[5-meth-oxy-2-(meth-oxy-carbon-yl)phen-yl] methyl-phospho-nate.

In the title phospho­nate, C19H21O9P, the dihedral angle between the benzene rings is 63.33 (3)°, and the P atom has a distorted tetra­hedral geometry, with angles in the range 101.30 (6)–120.38 (6)°. No significant inter­molecular inter­actions are observed in the crystal structure, and π–π inter­actions between symmetry-related benzene rings are beyond 4 Å.

1,2-Bis(4-methoxyphenoxy)ethane

The whole mol­ecule of the title compound, C16H18O4, is generated by twofold rotational symmetry; the twofold axis bis­ects the central C—C bond. The O—C—C—O torsion angle about the central C—C bond is 69.45 (16)°. Symmetry-related benzene rings are inclined to one another by 64.91 (8)°. In the crystal, mol­ecules are connected by C—H⋯O hydrogen bonds, forming a three-dimensional network.

3-Bromo-chroman-4-one.

The heterocyclic ring of the title compound, C9H7BrO2, obtained by bromination of 4-chromanone with copper bromide, adopts a half-chair conformation. The supramol­ecular structure is governed by a weak C—H⋯O hydrogen bond. There is also π–π stacking between symmetry-related benzene rings; the centroid–centroid distance is 3.9464 (18), the perpendicular distance between the rings is 3.4703 (11) and the offset is 1.879 Å.

Tris[2-(1,3-thiazol-2-yl-κN)-1H-benzimidazole-κN3]zinc(II) dinitrate ethanol hemisolvate monohydrate at 100 K

The Zn(II) center in the dicationic complex of the title compound, [Zn(C(10)H(7)N(3)S)(3)](NO(3))(2)·0.5C(2)H(5)OH·H(2)O, is in a distorted octahedral environment with imperfect noncrystallographic C(3) symmetry. Each 2-(1,3-thiazol-2-yl)-1H-benzimidazole ligand coordinates in a bidentate manner, with the Zn-N(imidazole) bond lengths approximately 0.14 Å shorter than the Zn-N(thiazole) bond lengths. Charge-assisted hydrogen bonds connect cations, anions and water molecules. A lattice void is occupied by an ethanol solvent molecule disordered about a crystallographic inversion center and π-stacking is observed between one type of symmetry-related benzene rings.

{4,4′-Dimethyl-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}copper(II) monohydrate

The asymmetric unit of the title compound, [Cu(C21H24N2O2)]·H2O, comprises half of a Schiff base complex and half of a water mol­ecule. The whole compound is generated by crystallographic twofold rotation symmetry. The geometry around the CuII atom, located on a twofold axis, is distorted square-planar, which is supported by the N2O2 donor atoms of the coordinating Schiff base ligand. The dihedral angle between the symmetry-related benzene rings is 47.5 (4)°. In the crystal, the water mol­ecule that is hydrogen bonded to the coordinated O atoms links the mol­ecules via O—H⋯O inter­actions into chains parallel to [001]. The crystal structure is further stabilized by C—H⋯π inter­actions, and by π–π inter­actions involving inversion-related chelate rings [centroid–centroid distance = 3.480 (4) Å].

{4,4′,6,6′-Tetraiodo-2,2′-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato}nickel(II)

The asymmetric unit of the title compound, [Ni(C19H16I4N2O2)], comprises half of a Schiff base complex. The NiII atom is located on a twofold rotation axis which also bis­ects the central C atom of the 2,2-dimethyl­propane group of the ligand. The geometry around the NiII atom is distorted square-planar, with a dihedral angle of 21.7 (3)° between the symmetry-related N/Ni/O coordination planes. The dihedral angle between the symmetry-related benzene rings is 27.9 (3)°. In the crystal, short inter­molecular I⋯I [3.8178 (9) and 3.9013 (10) Å] inter­actions are present.

2-Trifluoromethyl-1H-benzimidazol-3-ium nitrate

Ihe title salt, C8H6F3N2 +·NO3 −, the F atoms of the triflouromethyl group are disordered over two sets of sites in a 0.58 (2):0.42 (2) ratio. In the crystal, N—H⋯O hydrogen bonds link the cations and anions into chains running parallel to the b axis. There is π–π stacking between symmetry-related benzene rings with a centroid-centroid distance of 3.949 (3) Å. The crystal studied was a non-merohedral twin, with a 19% minor component.

{4,4′-Dimethyl-2,2′-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato}nickel(II) monohydrate

In the title compound, [Ni(C21H24N2O2)]·H2O, both the complex mol­ecule and the water mol­ecule lie on a twofold rotation axis. The NiII ion is coordinated in a distorted square-planar geometry by the tetra­dentate ligand. The dihedral angle between the two symmetry-related benzene rings is 47.12 (8)°. In the crystal, pairs of symmetry-related O—H⋯O hydrogen bonds form R 2 2(6) ring motifs. In addition, there are weak inter­molecular C—H⋯O hydrogen bonds, and π–π stacking inter­actions with a centroid–centroid distance of 3.4760 (8) Å.

(1E,2E)-1,2-Bis[1-(3-chlorophenyl)ethylidene]hydrazine

The title mol­ecule, C16H14Cl2N2, lies on an inversion center. The dihedral angle between the symmetry-related benzene rings is 0.02 (11)°. The mean plane of the central C(meth­yl)—C=N—N=C—C(meth­yl) unit forms a dihedral angle of 5.57 (12)° with the symmetry-unique benzene ring.

Trans-Tetraaquabis[1,3-bis(4-pyridyl)propane-κN]cobalt(II) biphenyl-4,4′-disulfonate monohydrate

In the title compound, [Co(C13H14N2)2(H2O)4](C12H8O6S2)·H2O, the cation, anion and uncoordinated water mol­ecule have crystallographically imposed twofold symmetry. The cobalt(II) atom exhibits a slightly distorted octa­hedral coordination geometry provided by two N atoms from two 1,3-bis­(4-pyrid­yl)propane ligands and the O atoms from four water mol­ecules. The dihedral angle between the pyridine rings in the ligand is 86.14 (11)°, whereas the dihedral angle formed by the symmetry-related benzene rings in the anion is 35.81 (12)°. In the crystal, cations, anions and water mol­ecules are linked into layers parallel to the ac plane by O—H⋯O and O—H⋯N hydrogen-bond inter­actions. The layers are further connected into a three-dimensional network by C—H⋯O hydrogen bonds.

(1S*,4′S*,5R*)-1-Isopropyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione

In the isoquinoline ring system of the title mol­ecule, C18H20N2O5, the N-heterocyclic ring is in a half-boat conformation. The dioxa-2-aza­spiro ring is essentially planar, with a maximum deviation of 0.029 (1) Å, and makes a dihedral angle of 30.63 (5)° with the benzene ring. The mol­ecular structure is stabilized by a weak intra­molecular C—H⋯O hydrogen bond, which generates a S(6) ring motif. In the crystal, mol­ecules are linked via weak inter­molecular C—H⋯O hydrogen bonds into a three-dimensional supra­molecular network. Additional stabilization is provided by π–π stacking inter­actions between symmetry-related benzene rings with a centroid–centroid distance of 3.6507 (5) Å.

Tetrakis(μ-3-azaniumylbenzoato)-κ3O:O,O′;κ3O,O′:O;κ4O:O′-bis[tetraaquaneodymium(III)] hexachloride tetrahydrate

The structure of the title compound, [Nd2(C7H7NO2)4(H2O)8]Cl6·4H2O, consists of dimeric cationic units related by an inversion centre. The two NdIII atoms are linked by two bridging bidentate carboxyl­ate groups and two bidentate chelating bridging carboxyl­ate groups, with an Nd⋯Nd separation of 4.1259 (4) Å. Each NdIII atom is nine-coordin­ated by five O atoms from the carboxyl­ate groups of the zwitterionic azaniumylbenzoate ligands and four from water mol­ecules. They adopt a distorted tricapped trigonal–prismatic arrangement. The dihedral angle between the mean planes of the benzene ring and the carboxlate groups are 7.7 (6) and 24.4 (5)°. The two carboxyl­ate groups are almost perpendicular to one another with a dihedral angle of 84.0 (7)°, while the two benzene rings are inclined to one another by 81.8 (2)°. The mol­ecular packing is stabilized by O—Hwater⋯Cl, O—Hwater⋯N, N—H⋯Cl, N—H⋯O, and O—Hwater⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid distance = 3.500 (3) Å] between symmetry-related benzene rings. All of the Cl− anions and the uncoordinated water molecules are disordered over two sets of sites with different occupancy ratios.

(1E,4E)-1,5-Bis(2,6-difluorophenyl)penta-1,4-dien-3-one

The mol­ecule of the title compound, C17H10F4O, is roughly planar, with a dihedral angle of 5.59 (14)° between the two phenyl rings. The mol­ecule has an E conformation with respect to the olefinic bonds. In the crystal, mol­ecules are connected through C—H⋯O hydrogen bonds and there is slipped π–π stacking [centroid–centroid distance = 3.7983 (18), slippage =1.309 ;Å] between symmetry-related benzene rings.

2,9-Bis(3,5-dimethyl-1H-pyrazol-1-yl-κN2)-1,10-phenanthroline-κ2N,N′](methanol-κO)(nitrito-κ2O,O′)cadmium(II) perchlorate

In the title complex, [Cd(NO2)(C22H20N6)(CH3OH)]ClO4, the CdII ion is in a distorted penta­gonal–bipyramidal CdN4O3 coordination geometry. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline ring system are 4.37 (19) and 5.84 (21)°. In the crystal, the anions and cations are connected by inter­molecular O—H⋯O hydrogen bonding, while pairs of weak inter­molecular C—H⋯O hydrogen bonds connect the cations into centrosymmetric dimers. In addition, there is a π–π stacking inter­action involving two symmetry-related benzene rings, with a centroid–centroid distance of 3.437 (3) Å.

(RS)-1-[5-(2-Chloropropyl)indolin-1-yl]ethanone

In the title compound, C13H16ClNO, the acetyl­indoline moiety is roughly planar (r.m.s. deviation = 0.0048 Å). The chloro­propyl group is out of the plane and is statistically disordered over two positions. Indeed, the Cl and CH3 groups located on the stereogenic carbon exchange with each other. The whole crystal is a racemate. Non-classical C—H⋯O hydrogen bonds between symmetry-related benzene rings stabilize the crystal structure.

Ethylenediammonium bis(3,4-dihydroxybenzoate) monohydrate

In the title compound, C2H10N2 2+·2C7H5O4 −·H2O, the cation lies on a centre of symmetry. The crystal structure is stabilized by various inter­molecular O—H⋯O and N—H⋯O hydrogen bonds, and by weak π–π stacking inter­actions with centroid–centroid distances between symmetry-related benzene rings ranging from 3.5249 (13) to 3.7566 (14) Å.

Catena-Poly[[diaquamagnesium(II)]-bis(μ-5-ammonioisophthalato-κ2O1:O3)

In the title compound, [Mg(C8H6NO4)2(H2O)2]n, the MgII ion lies on a twofold roatation axis and is coordinated in a slightly distorted octa­hedral environment. Pairs of bridging ammonium­isophthalate ligands connect symmetry-related MgII ions, forming chains along [010]. In the crystal, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link these chains into a three-dimensional network. The centroids of pairs of symmetry-related benzene rings within a chain are separated by 3.5707 (12) Å.