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A series of phenanthrothiophenes are designed and synthesized from polyarylthiophenes through regioselective Scholl reactions in one step using iron chloride as catalyst. The molecular structures of these heteroarenes displayed multiple twisted fjords, which perturb the shapes of the polycyclic frameworks to pack in slipped to near‐perfect face‐to‐face styles in parallel or antiparallel packings. Field‐effect transistor devices using single crystals of 6,12‐difluorodiphenanthro[9, 10‐b:9′, 10′]thiophene gave a hole mobility of 0.22 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

We develop a new statistical mechanical model to predict the molecular crowding effects in ion-RNA interactions. By considering discrete distributions of the crowders, the model can treat the main crowder-induced effects, such as the competition with ions for RNA binding, changes of electrostatic interaction due to crowder-induced changes in the dielectric environment, and changes in the nonpolar hydration state of the crowder-RNA system. To enhance the computational efficiency, we sample the crowder distribution using a hybrid approach: For crowders in the close vicinity of RNA surface, we sample their discrete distributions; for crowders in the bulk solvent away from the RNA surface, we use a continuous mean-field distribution for the crowders. Moreover, using the tightly bound ion (TBI) model, we account for ion fluctuation and correlation effects in the calculation for ion-RNA interactions. Applications of the model to a variety of simple RNA structures such as RNA helices show a crowder-induced increase in free energy and decrease in ion binding. Such crowding effects tend to contribute to the destabilization of RNA structure. Further analysis indicates that these effects are associated with the crowder-ion competition in RNA binding and the effective decrease in the dielectric constant. This simple ion effect model may serve as a useful framework for modeling more realistic crowders with larger, more complex RNA structures. [ABSTRACT FROM AUTHOR]

2,3-Dimethylpentacene (DMP) and 2,3-dimethyltetracene (DMT) were synthesized, characterized and employed as the channel material in the fabrication of thin-film transistors. The two methyl groups increase the chemical stability of the compounds versus the pristine acene analogues. The crystals maintain herringbone-like molecular packing, whereas the weak dipole associated with the unsymmetrical molecule induces an anti-parallel alignment among the neighbors. This structural motif favors layered film growth on SiO2/Si surface. Thin film transistors prepared on SiO2/Si and n-nonyltrichlorosilane-modified SiO2/Si at different substrate temperatures were compared. DMP-based transistors prepared on rubbed n-nonyltrichlorosilane-modified SiO2/Si substrate gave the highest field-effect mobility of 0.46 cm2/Vs, whereas DMT-based transistor gave a mobility of 0.028 cm2/Vs. [ABSTRACT FROM AUTHOR]

The semiconductor films of SrTiO3, a-Fe2O3 and their heterojunction SrTiO3/a-Fe2O3 were prepared on FTO (SnO2 : F on glass) substrates by the spin-coating method and their structures and properties were characterized by XRD, SEM and photoelectrochemical measurements, respectively. It was observed that the photocurrent and the incident photon to current conversion efficiencies (IPCE or external quantum efficiencies) of the SrTiO3/a-Fe2O3 heterojunction were higher than that of the single SrTiO3 or a-Fe2O3 film, particularly under visible light irradiation. The band structures of SrTiO3 and a-Fe2O3 were calculated. It was found that the charge carriers in a-Fe2O3 had large effective masses while the charge carriers in SrTiO3 had small effective masses at the bottom of the conduction band and at the top of the valence band, which meant weak mobility of holes photo-generated in a-Fe2O3 and strong mobility of holes excited in SrTiO3. As to the SrTiO3/a-Fe2O3 heterojunction, the special valence band structures of SrTiO3 improved the separation efficiency of charge carriers which had been photo-generated in a-Fe2O3. This led to the enhancement of photocurrent densities and external quantum efficiencies in the SrTiO3/a-Fe2O3 heterojunction photoanode. [ABSTRACT FROM AUTHOR]

A novel p-channel semiconductor pyreno[4,5-a]coronene has been synthesized and characterized. The highly fused π-conjugated framework has a twisted geometry with an excellent on-top cofacial π–π stacking in the crystal structure and with a centroid-to-centroid distance of 3.808 . Single-crystal field effect transistors based on the molecule exhibit a high mobility of ∼0.89 cm2V−1s−1and an on/off ratio of ∼6 × 104. [ABSTRACT FROM AUTHOR]

The title polymeric compound, {[MnHg(SCN)4(H2O)]-C4H8O2S}n, consists of slightly distorted MnN4O2 octahedra and HgS4 tetrahedra. Each MnII ion is bound to N atoms belonging to the thiocyanate (SCN) groups and to two O atoms of adjacent water ligands. The sulfolane molecule connects with the coordinated water molecule through hydrogen bonding. Each HgII atom is coordinated by four SCN S atoms. The two adjacent MnII atoms and two O atoms of bridging water molecules connect with one another and form a parallelogram. Each pair of MnII and HgII atoms is connected by an -SCN- bridge, forming an infinite three-dimensional structure. [ABSTRACT FROM AUTHOR]

In the title complex, (C8H20N)2[Cu(C3S5)2], each Cu atom is tetracoordinated by four dmit S atoms (dmit is 2-thio­xo-1,3-di­thiole-4,5-di­thiol­ate), forming a slightly distorted square-planar arrangement. The average Cu—S bond length is a little larger than the sum of the single-bond covalent radii. The S—Cu—S bond angles for the vicinal S atoms are somewhat larger than the typical right angle and the other two angles are much smaller than 180°. The [Cu(dmit)2]2− anions and tetraethyl­ammonium counter-cations form a layered arrangement in the crystal structure. [ABSTRACT FROM AUTHOR]

In the title complex, (C6H8N)2[Zn(dmit)2] (dmit is 2-thioxo-1,3-dithiole-4,5-dithiol­ate, C3S5), each Zn atom is coordinated by four dmit S atoms that define a distorted tetra­hedral arrangement. The crystal structure is stabilized by C—H⋯S hydrogen bonding and S⋯S contacts. [ABSTRACT FROM AUTHOR]

The title compound, C13H6O4S5, possesses crystallographically imposed mirror symmetry, with the atoms of the C=S group lying on the mirror plane. It is an example of the general formula [ RCO]2(dmit), where R is a furan ring and dmit is 2-thioxo-1,3-dithiole-4,5-dithiol­ate. The components exhibit some polarization of their mol­ecular–electronic structure. The dmit and furan moieties exhibit a high degree of conjugation, as the introduction of C=O connecting the conjugated furan (donor) and dmit (acceptor) rings forms a good conjugated system with high delocalization. A polar three-dimensional framework is built from a combination of inter­molecular contacts, namely S⋯S inter­actions and C—H⋯O hydrogen bonding. The structural characteristics lead to good second-order non-linear optical properties. [ABSTRACT FROM AUTHOR]

PVC disulfide (2SPVC) was synthesized by solution crosslink and its molecular structure was confirmed by infrared spectrum. 2SPVC's specific area is 36.1 m2·g-1 tested by stand BET method, and granularity experiment gives out the particle size of d0.5 = 11.3 μm. With SEM (Scanning Electron Microscope) experiment the surface morphology and particle shape of 2SPVC were observed. Cyclic voltammetry (scan rate: 0.5 mV·s-1) shows that 2SPVC experience an obvious S–S redox reaction in charge-discharge process. When 2SPVC was used as cathode material for secondary lithium battery in a 1 mol·L-1 solution of lithium bis(trifluoromethylsulfonyl) imide (Li(CF3SO2)2N) in a 5:45:50 volume ratio mixture of o-xylene (oxy), diglyme (DG) and dimethoxymethane (DME) at 30°C, the first discharge capacity of 2SPVC is about 400.3 mAh·g-1 which is very close to its theoretical value (410.5 mAh·g-1) at a constant discharge current of 15 mA·g-1. It can retain at about 346.1 mAh·g-1 of discharge capacity after 30 charge-discharge cycles. So 2SPVC is a very promising cathode candidate for rechargeable lithium batteries. [ABSTRACT FROM AUTHOR]

The article presents information on the structure of the coordination compound 4'-[4-(Imidazol-1-yl)phenyl]-2,2':6',2"-terpyridine (IPTP). Polypyridine ligands, in particular, the chelating ligand terpyridine and its functionalized derivatives have been studied extensively as outstanding complexing agents for a wide range of transition metal ions. IPTP is a novel compound containing terpyridine and imidazole coordination sites. In the study it was synthesized and characterized by 1H NMR, 13C NMR and single-crystal X-ray diffraction.

CdHg(SeCN)4 has an extended three-dimensional network structure in which the slightly distorted CdN4 and HgSe4 tetrahedra are connected by –SeCN– bridges. [ABSTRACT FROM AUTHOR]

Three new organic-lanthanide frameworks based on a flexible H3L acid, namely, [Er3(L)3(H2O)4]·5.64H2O (1), [Dy3(L)3(H2O)4]·2H2O (2), and [Tb3(L)3(H2O)4]·2H2O (3), where H3L = 5-(benzonic-4-ylmethoxy)isophthalic acid, have been synthesized under mild solvothermal conditions. Compounds 1–3are isostructural, in which L ligands linked the lanthanide(III) ions (M) to generate two kinds of cages, [M2L]6and [M2L2]12. These cages are further connected through sharing the M(III) atoms to yield a 3D framework with 1D channels. Topologically, the 3D framework belongs to a binodal (3,6)-connected net with the point symbol of (42.6)(44.62.86.103). Furthermore, compounds 1and 2display interesting emissions in the near-IR regions. Compound 3exhibited strong green luminescence upon 249 nm excitation. The adsorption property of 1has also been investigated. [ABSTRACT FROM AUTHOR]

In the title complex, (C19H42N)[Ni(C3S5)2], the Ni atom is coordinated by four 2-thioxo-1,3-dithiole-4,5-dithiol­ate (dmit) S atoms. The [Ni(dmit)2]− monoanion has a planar geometry, with the central Ni atom and the four coordinated S atoms forming an NiS4 square plane. There are S⋯S inter­molecular contacts in the crystal structure. [ABSTRACT FROM AUTHOR]

The molecules of the title compound, C11H13N3O3, are linked by O—H⋯N and N—H⋯O interactions into a linear hydrogen-bonded chain. [ABSTRACT FROM AUTHOR]

Two diaryl B- and N-substituted truxene charge-transfer compounds B3 and N3 have been synthesized. The fluorescence intensities of several nonfunctionalized truxene compounds are I order of magnitude weaker than that of B3 and N3. To reveal the structure-property correlations, the X-ray structures of B3 and N3 and their precursors 3 and 4 have been determined. The extended molecular dimension, the especially shortened B-C bond, and the improved planarity of B3 can serve as direct structural evidence for the charge transfer. [ABSTRACT FROM AUTHOR]

The title compound (alternative name dimethyl croconate), C7H6O5, is the first example of a croconate ether. The mol­ecule is essentially planar and exhibits a local symmetry ( C2 v) that is different from that shown by the croconate dianion ( C5 h), indicating that the geometry of these compounds is very sensitive to the electric charge state. [ABSTRACT FROM AUTHOR]