Plane Of Phenyl Ring Research Articles

Mapping of Domain Orientation and Molecular Order in Polycrystalline Semiconducting Polymer Films with Soft X‐Ray Microscopy

AbstractWe utilize scanning transmission X‐ray microscopy (STXM) to study the domain structure of polycrystalline films of the semiconducting polymer poly(9,9’‐dioctylfluorene‐co‐benzothiadiazole) (F8BT). By taking several images at different orientations of the film with respect to the polarization of the X‐ray beam, we are able to compute quantitative maps of molecular alignment/order and molecular orientation, including both the backbone direction and phenyl ring plane orientation, as well as the in‐plane and out‐of‐plane components. We show that polycrystalline F8BT films consist of well‐ordered micron‐sized domains with the transition from one domain orientation to another characterized either by a smooth transition of orientation or by ∼ 200 nm wide disordered domain boundaries. The morphology of the disordered domain boundaries resemble the electroluminescence patterns observed previously in F8BT light‐emitting field‐effect transistors suggesting that charge trapping at these disordered domain boundaries facilitates charge recombination in ambipolar operation. A relatively narrow distribution of local average tilt angles is observed that correlates with film structure, with the ordered domains in general showing a higher tilt angle than the disordered domain boundaries. We also use secondary electron detection to image the surface domain structure of polycrystalline F8BT films and demonstrate that the polycrystalline structure extends to the film/air interface. Finally, we calculate ideal NEXAFS spectra corresponding to a perfect F8BT crystal oriented with the 1s – π* transition dipole moment parallel and perpendicular to the electric field vector of a perfectly linearly polarized X‐ray beam.

Unsymmetrical diimine complexes of iron(ii) and manganese(ii): synthesis, structure and photoluminescence of an isomer

Two bis(unsymmetrical diimine) complexes of (L(NO(2))(ϕ1))(L(NO(2))(ϕ2))M(II)Cl(2) family with M = Fe and Mn, are reported (L(NO(2))(ϕ) = (E)-3-nitro-N-(pyridine-2-ylmethylene)aniline; ϕ = dihedral angle between the diimine unit including pyridine ring and the phenyl ring planes). Pure tcc-(L(NO2)(33.6))(L(NO2)(79.3))Fe(II)Cl(2)·0.5H(2)O (1) and tcc-(L(NO2)(32.0))(L(NO2)(79.4))Mn(II)Cl(2)·0.5H(2)O (2) isomers have been successfully isolated in high yields and characterized by elemental analyses, variable temperature magnetic susceptibility measurements, IR, mass, UV-vis and Mössbauer spectra including the single-crystal X-ray structure determinations that identified strong intermolecular non-bonding interactions in lattice (tcc refers to trans-cis-cis positions with respect to pyridine N-imine N-Cl donors). Geometries optimizations of all possible tcc, ttt, ctc, ccc and cct isomers of iron at the B3LYP/DFT level in gas-phase have shown that the tcc-isomer incorporating two non-equivalent ligands as in (L(NO(2))(42))(L(NO(2))(61))Fe(II)Cl(2), 1 (g), is stabilized by 6-20 kJ mol(-1) compared to other isomers where two ligands are equivalent. The frozen methanol glasses of 1 and 2 are luminescent at 77 K (1: λ(ext) = 370, λ(em) = 521 nm, χ(2) = 1.3, τ(avg) = 0.57 ns; 2: λ(ext) = 368, λ(em) = 524 nm, χ(2) = 1.1, τ(avg) = 0.90 ns). The DFT calculations have identified four closely spaced localized π(*) orbitals comprising of two non-equivalent ligands as UPMOs. The features contrast the tcc-isomer of (L(ϕ))(2)Fe(II)Cl(2) (3), congener of 1 without -NO(2) substitution and non-emissive (bpy)(2)Fe(II)Cl(2) (4) where two ligands are equivalent. TD-DFT calculations have assigned intra-ligand (IL) and ligand to ligand charge transfer (LLCT) dominated excited states as the origin of luminescence of 1 and 2.

Mefenacet [2-(1,3-benzothiazol-2-yloxy)-N-methyl-N-phenylacetamide

The title compound, C16H14N2O2S, crystallizes with two independent mol­ecules in the asymmetric unit. The dihedral angles between the plane of the benzothia­zole ring system and the phenyl ring plane are 51.63 (7) and 60.46 (5)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions contribute to the stabilization of the packing.

5-Chloro-3-[(E)-1,2-diphenylethenyl]-1H-indole

In the title compound, C22H16ClN, the pyrrole system makes a dihedral angle of 68.9 (1)° with the plane of phenyl ring at the ethenyl 1-position. An intra­molecular C—H⋯π inter­action is observed. In the crystal, inter­molecular C—H⋯π inter­actions link the mol­ecules into infinite chains running along the b axis.

ChemInform Abstract: (Z)-2,2,5,5-Tetramethyl-3,4-diphenyl-3-hexene: A Cofacial Stilbene.

C22H28 , M r = 292.47, orthorhombic, Pbca, a = 18.154 (2), b = 16.973 (2), c = 12.081 (1)A, V = 3722.7/~3, Z = 8, Dx = 1-04 g cm-3, Mo Ka radia- tion, a = 0.71073 A,/z = 0.5 cm-1, F(000) = 1280, T = 294 (1) K, 5499 unique reflections, R = 0.040, wR = 0-046, S = 1.34 for 920 observed unique reflec- tions. Steric repulsion of the vicinal tert-butyl groups forces them back into the geminal phenyl rings. In order to avoid further steric strain, the phenyl rings assume a cofacial or face-to-face relationship. The planes of both phenyl rings are perpendicular to the plane of the central double bond with a nearest point of contact at 2.65 A. The central double bond is normal.

ChemInform Abstract: A 1H NMR Investigation of the Conformational Properties of 1,2- Dimethoxybenzene.

The 1H NMR spectrum of a sample of 1,2-dimethoxybenzene dissolved in a nematic solvent (I35) has been analysed to yield a set of partially-averaged dipolar couplings, Dij. These are used to test models for the conformations adopted for the two OCH3 groups relative to the ring. It is concluded that a single conformation, or a set of symmetry-related conformations is not consistent with the data. The dipolar couplings are used to derive the distribution among the 16 minimum energy structures which are possible if it is assumed that the C–O–C planes can only be either coplanar with, or perpendicular to, the phenyl ring plane.

1-[4-(Difluoromethoxy)phenyl]-N-(3,4-dimethoxyphenyl)-1H-1,2,4-triazole-3-carboxamide

Two crystallographically independent mol­ecules, A and B, with similar conformations are present in the asymmetric unit of the title compound, C18H16F2N4O4. In mol­ecule A, the plane of the 1,2,4-triazole ring is tilted relative of the 4-difluoro­meth­oxy-substituted and the 3,4-dimeth­oxy-substituted benzene rings by 6.5 (2) and 16.4 (1)°, respectively. The –CHF2 group is twisted away from the plane of the benzene ring, with a dihedral angle between the O—C bond of the OCHF2 group and the plane of the adjacent phenyl ring of 38.6 (3)°. The corresponding parameters for mol­ecule B are 7.7 (1), 9.5 (2) and 25.2 (2)°. In both mol­ecules, the conformations are stabilized by intra­molecular N—H⋯N and C—H⋯O hydrogen bonds. There are also C—H⋯π contacts between the methyl groups and the benzene rings, and π–π stacking inter­actions between the benzene rings of adjacent parallel A mol­ecules [centroid–centroid distance = 3.8942 (17) Å]. π–π inter­actions are also observed between the triazole ring and one of the benzene rings of parallel B mol­ecules [centroid–centroid distance = 3.7055 (16) Å].

ChemInform Abstract: The Absolute Configuration of Sertraline (Zoloft) Hydrochloride.

We report the results of a crystal structure determination of the S,S stereoisomer of sertraline (Zoloft) hydrochloride {[(1S-cis)-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-1-naphthyl]methylammonium chloride, C 17 H 18 -Cl 2 N + .Cl - }, which is the active form used as an antidepressant in humans. The conformation of sertraline has two planar phenyl rings that are approximately perpendicular to each other, and an unsaturated ring in a half-chair conformation.

Stereoselective non-equivalent bis-diimine coordination to Co(II) ion: Structure, luminescence and density functional theory calculations

Stereoselective coordination affording a luminescent tcc-isomer of dihalobis(diimine)Co(II) family in which two photoactive diimine ligands (L NO2 ϕ) are unsymmetrical and non-equivalent is reported (L NO2 ϕ = ( E)-3-nitro- N-(pyridine-2-ylmethylene)aniline; ϕ = dihedral angle between the diimine unit including pyridine ring and the phenyl ring planes; tcc refers trans–cis–cis positions with respect to pyridine nitrogen-imine nitrogen-chloride donors). The single step reaction of 2-pyridinecarboxaldehyde, 3-nitro aniline and anhydrous cobalt dichloride affords only the tcc-(L NO2 ϕ1)(L NO2 ϕ2)Co IICl 2 as the product which is characterized by IR, Mass, UV–Vis spectra and magnetic susceptibility measurements. Single crystal X-ray structure determination has established the orientation of the two ligands in the crystal as (L NO2 33.7)(L NO2 79.7)Co IICl 2·0.25CH 3OH ( 1). The isomer is luminescent in frozen methanol glass at 77 K with the excitation and emission maxima respectively at 370 and 525 nm. The average luminescence life time is 1.86 ns measured on exciting at 356 nm. Density functional theory (DFT) calculation shows that the non-equivalence of the two diimine ligands prevails in the gas phase also and the geometry is (L NO2 41.0)(L NO2 60.5)Co IICl 2. The calculation has identified four types of closely spaced localized π ∗ orbitals as unoccupied photoactive molecular orbitals (UPMOs). TD-DFT calculations have assigned the Co(II) to π ∗ charge transfer (MLCT) and π to π ∗ of charge transfer (LLCT) as the primary origin of absorption above 340 nm in methanol. Pendant nitro groups of the ligands and their intermolecular interactions have been the driving force of the stereoselectivity of the product. The binuclear L 4Co 2Cl 4 unit of 1 has constructed the helical 2D assembly and cis-CoCl 2 mediated strong inter-helices H-bonding interactions result the channeled 3D framework. Geometry optimization of other possible ttt, ctc, ccc and cct isomers has established that in the gas phase, the tcc-isomer is more stable at least by 20–42 kJ mol −1 compared to other isomers where the two diimine ligands are equivalent.

2-Bromo-p-terphenyl

In the title compound, C18H13Br, the dihedral angles between the mean planes of the central benzene ring and the mean planes of the outer phenyl and bromo­phenyl rings are 33.47 (8) and 66.35 (8)°, respectively. In the crystal, weak C—H⋯π and inter­molecular Br⋯Br [3.5503 (15) Å] inter­actions contribute to the stabilization of the packing.

Intramolecular noncovalent interactions: Bis(toluene)chromium(0) conformers

The structure of trans- and cis-conformers of bis(toluene)chromium(0) and the intramolecular interactions in them are studied by means of MP2 and density functional theory along with topological and NBO analyses. It was concluded for the first time that the locations of two hydrogen atoms of each methyl group between the phenyl ring planes in the most stable cis-conformer of bis(toluene)chromium(0) are largely determined by the stabilizing interactions of methyl C-H bonds and their hydrogen atoms with the metal atom and chromium-carbon bonds. It was concluded from the obtained data that the C-H...Cr contacts in the studied conformers should be considered as hydrogen bonds rather than agostic interactions. Contrary to the existing conception of the quantum theory of atoms in molecules, repulsive interaction is shown to occur between the pairs of hydrogen atoms of the two methyl groups in bis(toluene)chromium(0) cis-conformers rather than the stabilizing hydrogen-hydrogen interactions.

N-(3,4-Dichlorophenyl)-3-oxobutanamide

In the title compound. C10H9Cl2NO2, the acetamide residue is twisted out of the phenyl ring plane by 25.40 (9)°. An intra­molecular C—H⋯O close contact is observed. The N atom of the butanamide unit forms an inter­molecular N—H⋯O hydrogen bond with the symmetry-related carbonyl O atom, inter­linking mol­ecules into a C(4) chain along [100]. Additional C—H⋯O inter­molecular inter­actions and Cl⋯Cl contacts [3.4364 (8) Å] contribute to the stability of the crystal packing.

1,4-Di-n-heptyloxy-2,5-dinitrobenzene

The complete molecule of the title compound, C20H32N2O6, is generated by crystallographic inversion symmetry. The two mutually trans nitro substituents are hence in fully eclipsed conformation and also twisted by 43.2 (2)° with respect to the phenyl ring plane. The benzene-connected portions of the alk­oxy substituents lie almost coplanar with the ring [C—O—C—C torsion angle = 2.0 (2)°]. In the crystal, weak C—H⋯O interactions link the molecules.

N-(2-Bromobenzyl)-N′-(2-pyridyl)benzene-1,2-diamine

In the title compound, C18H16BrN3, mol­ecules are linked into dimers by co-operative inter­molecular N—H⋯N hydrogen bonding. Only one N—H group is involved in hydrogen bonding. The planes of the pyridine and bromo­phenyl rings are twisted by 61.49 (3) and 79.11 (8)°, respectively, from the plane of the central phenyl ring.

Ethyl (E)-1-(2-styryl-1H-benzimidazol-1-yl)acetate

In the title compound, C19H18NO2, the dihedral angle between the benzimidazole and phenyl ring planes is 18.18 (17)°. The atoms of the ethyl side chain are disordered over two sets of sites in a 0.50:0.50 ratio. In the crystal, inter­molecular C—H⋯O hydrogen bonds and C—H⋯π contacts help to consolidate the packing.

2,9-Dimethyl-4,7-diphenyl-1,10-phenanthrolin-1-ium tetra-chloridoaurate(III).

Both the cation and anion of the title compound, (C26H21N2)[AuCl4], are disposed about a plane of mirror symmetry. The 2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinium ring is oriented at a dihedral angle of 44.2 (1)° with respect to the planar phenyl ring systems. The AuIII atom has a square-planar environment defined by four Cl atoms. The crystal structure is stabilized by C—H⋯π and Au⋯π ring–metal (3.551 Å) inter­actions. In the crystal structure, the mol­ecules stack along the c axis via N—H⋯N hydrogen-bond inter­actions.

Lophine (2,4,5-triphenyl-1H-imidazole)

The title compound, C21H16N2, has been known since 1877. Although the crystal structure of 36 derivatives of lophine are known, the structure of parent compound has remained unknown until now. The three phenyl rings bonded to the imidazole core are not coplanar with the latter, with dihedral angles of 21.4 (3), 24.7 (3), and 39.0 (3)°, respectively, between the phenyl ring planes in the 2-, 4- and 5-positions of the imidazole ring. The mol­ecules are packed in layers running perpendicular to the b axis. Although there are acceptor and donor atoms for hydrogen bonds, no such inter­actions are detected in the crystal in contrast to other lophine derivatives.

Dynamics and mechanism of the Crystal II → smecticG phase transition in TB7A by a temperature‐dependent micro‐Raman study and DFT calculations

AbstractThe solid to smecticG (SmG) phase transition in a Schiff base liquid crystalline compound, terepthal‐bis‐heptylaniline (TB7A), is monitored in situ by temperature‐dependent Raman microspectroscopy, using the band of a CH in‐plane bending mode as a marker. Contrary to the earlier report of a sudden wavenumber shift, the in situ measurement shows very clearly that a new Raman band at ∼1160 cm−1 appears at the Crystal II → SmG transition. The dynamics of this phase transition is discussed in terms of a triple well potential below 210 K and a double well potential above 210 K. The phase transition essentially takes place as a result of intra‐molecular rotation about the long molecular axis. The optimization energy at various fixed dihedral angles, (CCCN) are calculated using density functional theory (DFT) at the B3LYP/6‐31G* level of theory. The relative energy at each dihedral angle is calculated relative to optimization energy obtained without any constraints and plotted as a function of dihedral angle (Φ) between the adjacent phenyl ring planes, which also shows a double well potential at room temperature. Copyright © 2009 John Wiley & Sons, Ltd.

2-Benzoyl-1,1-diethyl-3-phenylguanidine

In the title tetrasubstituted guanidine, C18H21N3O, the guanidine and carbonyl groups are not coplanar, as reflected by the torsion angles involving the N=C atoms [17.6 (3), −141.68 (17) and 42.2 (3)°]. This is probably due to the absence of an intra­molecular N—H⋯O hydrogen bond, forming a six-membered ring, and is commonly observed in this class of compounds. In the crystal structure, centrosymmetric dimers are formed via pairs of inter­molecular N—H⋯O hydrogen bonds. The dihedral angles between the guanidine plane and the phenyl ring and benzoyl plane are38.06 (9) and 41.54 (7)°, respectively.

X‐ray studies of the crystalline and nematic phases of 4′‐(3,4,5‐trifluorophenyl)‐4‐propylbicyclohexyl

The crystal and molecular structures of the nematogenic compound 4′‐(3,4,5‐ trifluorophenyl)‐4‐propylbicyclohexyl (3ccp‐fff) were determined by direct methods using single crystal X‐ray diffraction data at 293 K. The compound (C21H29F3) crystallises in the triclinic system with space group P1¯ and Z = 2. The unit cell dimensions are a = 5.3715(14) Å, b = 10.559(3) Å, c = 16.891(4) Å, α = 86.331(5)°, β = 85.196(6)° and γ = 81.938(5)°. The structure was refined by the least squares method to an R‐value of 0.058 for 1398 observed reflections. The fluorine atoms are in the plane of phenyl ring. Both the cyclohexyl groups are found to be in chair conformation and they are coplanar (dihedral angle 0.8°). The molecules were found to be in the most extended conformation. Results of the crystal structure analysis were compared with that obtained from molecular modelling and also with that of the related bifluorinated compound (3ccp‐ff). An antiparallel imbricated mode of packing of the molecules is found in the crystalline state. Several van der Waals interactions are observed between the neighbouring molecules, suggesting evidence for existence of molecular packings in head‐to tail configuration. The average fluctuation length of the molecules within the nematic phase, determined from a small‐angle X‐ray diffraction study, is found to be about 1.4 times more than molecular length, providing further evidence for the existence of antiparallel associations between neighbouring molecules.