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The Say’un-Masilah basin is one of the most prolific sedimentary basins in Yemen, and therefore it has attracted the attention of geologists and geophysicists for hydrocarbon prospection and exploration. The main objective of this research is to study the structural and stratigraphic subsurface features as well as to determine the lithological contents of the Sharyoof oil field, Block 53, in the Mesozoic rift basin, eastern Yemen, using seismic and well log data. The basic inputs in this study include log data, collected from six wells, such as gamma ray (GR), caliper, deep, and shallow laterlog resistivity (LLD, LLS), micro-spherically focused log (MSFL), photoelectric absorption index (PEF), and porosity tools (density, neutron, and sonic). In addition, seismic sections including 15 lines 2D, well tops, bottom, sheck shot, well header, and deviations were used to accomplish this study objective. The obtained results from the seismic profiles interpretations demonstrated the existence of a series of normal faults dissecting most of the mapped horizons toward NE-SW (major faults) and NW-SE and W-E (secondary faults) creating several graben and horst structures. Moreover, results analysis of the well log data indicates that the main lithology content is dominated by the presence of the carbonates (limestone and dolomite) in the Sa’ar Formations and Qishn Carbonates Member while the sandstones for the Qishn Clastics, Harshiyat, and Mukalla Formations. The lithostratigraphy succession consists of rock units ranging in age from Early to Upper Cretaceous age (from Sa’ar to Mukalla Formations). Furthermore, seismic section data allowed determining the subsurface feature styles from reflections maps of both isochronous (two-way travel time) on the tops of the Sa’ar to Mukalla Formations. They reflect the occurrence of several distinct structures (anticlines, synclines, and faults), added to trends of faulting (NW-SE dissected by NE-SW). The novel contribution of the present work consists in the identification of the structural characteristics of the Lower and Upper Cretaceous formations of Block 53 using new seismic lines. Therefore, the obtained results of this study allow determining the sections and composition holding the hydrocarbon reservoir characteristics. As such, this research can be used as a reference study.

The distribution, contamination status, and ecological risks of heavy metals in Tahaddart estuary were investigated. 24 surface sediment samples and two cores were collected and analyzed for major (Al and Fe), heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn), and grain size composition. The heavy metals assessment was carried out using different environmental indices. The results indicated that the spatial distribution patterns of Al, Fe, and Zn were mainly determined by the distribution of the finer grained fraction (

Controlled living anionic polymerization of cyanoacrylates promoted by a hydrogenated frustrated Lewis pair ([TMPH+][HB(C6F5)3–]). Preparation of designed block copolymers., A hydrogenated frustrated Lewis pair ([TMPH+][HB(C6F5)3–]) promotes controlled living ionic polymerization of cyanoacrylates. Controlled growth of various homopolymeric CAs through sequential monomer addition has been achieved, in addition to CA block copolymers with controlled block sequences for the first time in the long history of these materials.

International audience; The present research presents the first large-scale analysis of heavy metal assessment in the Moroccan Atlantic shelf. This work provides scientific basis for future studies on environmental research and fills the gap in knowledge on the worldwide continental platforms.Metal distributions identified three different zones, mainly influenced by industrial and urban sewer (northern areas), agriculture runoffs (central zone), and estuarine discharges (southern areas), respectively. In the north part of the shelf, metal enrichments are observed near industrial and urban sewer mouths (Casablanca and Mohammedia cities). In the south and central areas, the probable absence of human impact on sediments is attributed to effective trapping in the estuary (Oum Er Rbia) and coastal zones, as well as dilution with less contaminated sediments and shelf sediments and removal with fine fractions due to estuary discharges.

Diyne polycyclotrimerizations initiated by transition-metal catalysts afforded hyperbranched polyphenylenes, which exhibited low viscosity, outstanding thermal stability, and small optical dispersion. Under optimized reaction conditions, polycyclotrimerizations of 1,8-nonadiyne (1) and 1,9-decadiyne (2) catalyzed by TaCl5−Ph4Sn produced hyperbranched poly(1,2,4-benzenetriyl-1,5-pentanediyl) (3) and poly(1,2,4-benzenetriyl-1,6-hexanediyl) (4),1-5 respectively, in high yields (up to 93%). The polymers were completely soluble and film-forming, and possessed high molecular weights (Mw up to ∼1.4 × 106) but low intrinsic viscosities ([η] down to 0.13 dL/g). Their structures and properties were analyzed and evaluated by IR, UV, NMR, SEC, TGA, DSC, spectrofluorometry, light scattering, and spectroellipsometry. The structural characterizations confirmed the expected hyperbranched molecular architectures of 3 and 4 (comprising of 1,2,4-benzene rings and α,ω-alkyl spacers) and revealed the regioselective feature of...

The π-conjugated polymers poly-1 and poly-2 composed of vinylogous tetrathiafulvalene (TTF) units were obtained by electrochemical polymerization of 2,5-di(benzylidene)-1,3,4,6-tetrathiapentalene (...

The helical chirality and self-assembling structures of an unnatural polymer, poly(p-ethynylbenzoyl-l-valine) (1), are readily manipulated by a simple environmental perturbation of pH change. The amino acid appendages of l-valine create an asymmetric force field, inducing the polyacetylene backbones to helically rotate, and form intra- and interchain hydrogen bonds, stabilizing the screw-sense conformation of the polymer chains. The polymer exhibits a large Cotton effect in methanol, which decreases with an increase in pH upon addition of KOH into the polymer solution. The change in the chain helicity is reversible: the unfolded polymer chains refold back to their original helical conformations when the solutions are neutralized. Natural evaporation of the methanol solutions of 1 on mica gives long, bundled nanofibers of macromolecular assemblies; in contrast, evaporation of the methanol/KOH solutions yields short, unraveled nanofibers with sizes of roughly single macromolecular chains. The ionization of...

Most of the existing metal carbonyl catalysts for acetylene polymerizations need to be preactivated by chlorine-containing additives or by UV irradiation in halogenated solvents. In this work, we developed a series of “simple” metal carbonyl catalysts of general structure M(CO)xLy (M = Mo, W), none of which require additives or pre-photoirradiation, most of which are air- and moisture-stable, and some of which work well in nonhalogenated solvents. The acetonitrile complexes M(CO)3(NCCH3)3 initiated polymerizations of a variety of mono- and disubstituted acetylenes at room temperature. The arene and diene complexes W(CO)3(mes) and Mo(CO)3(nbd) (mes = mesitylene, nbd = 2,5-norbornadiene) are tolerant of polar groups and effected polymerizations of functional acetylenes containing ester, ether, and cyano groups. The halogenated complexes MI2(CO)3(NCCH3)2 catalyzed polymerizations of phenylacetylene in toluene. The chlorine-containing acetylene monomers ClC⋮CC6H5 and ClC⋮CC6H13 were readily polymerized by the...

The mechanism of the oxidative polymerization of di(benzylidene)tetrathiapentalenes (R−DBTTP; where R = H, OCH3, CF3) into linearly extended TTF polymers has been investigated by cyclic voltammetry...

1,3,4,6-tetrathiapentalene-2,5-dione ( 1 ) reacts in a Wittig-type fashion with aromatic/aliphatic aldehydes 2a - h upon heating in neat triethyl phosphite to bis-substituted tetrathiapentalenes ( 3a - h ), which can be oligo-/polymerized oxidatively to give vinylogous TTF derivatives or highly conducting, polymeric solids ( σ RT = 1 S/cm), respectively.

A simple process for fast fabrication of thin films with biomimetic morphological structures from a group of linear homopolymers is developed. Natural evaporation of tetrahydrofuran, chloroform, and hexane-dichloromethane solutions of poly(phenylacetylene)s that contain amino acid and ethylene glycol moieties under ambient conditions instantly produces three-dimensional porous films with structural patterns reminiscent of honeycombs and radiolarian shells. Morphological analysis by optical and electronic microscopy suggests that vesicles of the amphiphilic polymers serve as building blocks in the self-organization to the biomimetic structures.

[structure: see text] Oligothienyl-substituted paracyclophanes bearing alpha-thienyl substituents, which block polymerization at these sites, undergo oxidation to form stable radical cations and dications. Splitting of the first voltammetric oxidation wave of stacked dimers into two single-electron processes corresponding to formation of the stacked mono(radical cation) and the stacked bis(radical cation) illustrates the influence of pi-stacking on the behavior of conjugated chains, which serve as models for stacked polarons in conjugated polymers.

The photo-aligning materials based on azodye layers are proposed. The azodye aligning layers enable (i) high order parameter; (ii) excellent alignment quality of LCD with a high contrast ratio; (iii) temperature stability, suitable for LCD manufacturing; (iv) perfect adhesion and high voltage holding ratio due to the specific molecular groups (v) pretilt angle generation. The azodye layers can be used to fabricate thin internal patterned (pixelated) polarizers with different local orientations of the absorption axis and/or absorption colors. Our new methods allow to produce defect-free highly uniform alignment of lyotropic LC or iodine-doped azodye layers themselves with a fine resolution of the polarization pattern. The photo-aligned internal polarizers are cost-effective and enable new LCDs with excellent electro-optical response, including good viewing angles and high brightness. We prepared an internal phase retarder using UV-cured photo-polymerized material. 4-(6- acryloyloxyhexyloxy) benzoic acid had been synthesized and the synthesis procedure was modified for a better yield. We had shown that by applying an electric or magnetic field, the director deformation of the liquid crystalline monomer could be in-situ UV-cured for the optimal phase compensation generation.

Development of advanced polymeric materials with both liquid crystallinity and light emissivity is of scientific interest and technological importance. In this study, we studied light emission from tetrahydrofuran solutions of a liquid crystalline polyacetylene, poly(11-{[(4'-heptoxy-4- biphenylyl)carbonyl]oxy}-1-undecyne), in the electrical field. The field exerts little effect on the photoluminescence of the polymer solution with a low concentration (0.10 mM). The photoluminescence of a concentrated solution (11.3 mM) is, however, noticeably quenched under an electrical field with a field strength of > 300 kV/m. When the field strength is increased to >= 367 kV/m, the bimodal emission spectrum of the solution changes to a monomodal one. Thus, both the emission intensity and spectral profile of the luminescence of the concentrated solution can be tuned by the electrical field, which is probably caused by the aggregate dissociation and mesogen realignment induced by the external stimulus.

The monomeric tetrathiapentalene precursor 1 can be polymerized oxidatively in one step to the charged vinylogous tetrathiafulvalene derivative 3. The polymerization of 1 occurs in consecutive steps via radical intermediates. Reduction of 3 gave the neutral, soluble polymer 4 which comprises approximately 50 monomeric units (M w = 20000).

The results of spectroelectrochemical ESR studies as well as of in situ conductivity measurements performed on poly[(2,5-dibenzylidene)-1,3,4,6-tetrathiapentalene] (polyDBTTP 1) are presented. The polymer comprises polaron/bipolaron systems corresponding to the presence of three redox systems. The relative electrical resistivity strongly depends on the applied potential and correlates well with the spin density. A partially oxidized state 2 bearing one positive charge per monomer unit accounts for the conducting properties of the material.

The preparation of the first π-conjugated TTF polymer composed entirely of vinylogous, linearly fused TTF moieties has been achieved by oxidative polymerization of 2,5-di(benzylidene)-1,3,4,6-tetrathiapentalene.

Two new general approaches to TTF-based donor molecules have been developed. Route A gave, after basic cleavage of thiapendione (1) and direct alkylation of intermediate (2), the corresponding 4,5-disubstituted 1,3-dithiol-2-ones of general formula 4 as exemplified in Schemes 1 and 2. The more versatile route B involves isolation of the unstable intermediate 2 as chelate complex 3, which then gives upon treatment with alkyl/acyl halides compounds of type 4. Compounds (4) can either be coupled/cross-coupled in triethyl phosphite in known manner to give symmetric/asymmetric donors molecules or be used as precursors for the preparation of other sulfur containing heterocycles or metal complexes. Versatility, yields and high purity of intermediates and final products offer an interesting alternative to literature procedures

The electropolymerization mechanism of (2,5-dibenzylidene)-1,3,4,6-tetrathiapentalene ( 3 ) has been investigated by cyclic voltammetry. Standard oxidation potential and lifetime of radical-cation intermediate (RC) have been determinated by fast scan voltammetry. The initial steps ot the polymerization involve coupling of two RC to the corresponding dimeric dication, as evidenced by the variation of peak potentials with the scan rate.