Synthesis of B/Si Bidentate Lewis Acids, -(Fluorosilyl)borylbenzenes and -(Difluorosilyl)borylbenzenes, and Their Fluoride Ion Affinities.

Herein, we report detailed studies on a series of -(silyl)(boryl)benzenes (), in which the two Lewis acid centers consisting of silicon and boron atoms are linked via an -phenylene skeleton. -(Fluorosilyl)(dimesitylboryl)benzenes and were prepared by the reaction of fluorodimesitylborane with [-(fluorodimethylsilyl)phenyl]lithium () and [-(fluorodiphenylsilyl)phenyl]lithium (), respectively. -(Difluorosilyl)(dimesitylboryl)benzenes and were also prepared by the reaction of fluorodimesitylborane with -{[di(methoxy)methylsilyl]phenyl}lithium () and -{[di(methoxy)phenylsilyl]phenyl}lithium (), respectively, and their subsequent treatment with HF·pyridine.

Intramolecular Activation of C-O Bond by an -Boryl Group in -(Alkoxysilyl)(diarylboryl)benzenes.

Halogen-lithium exchange reaction of -(silyl)bromobenzene with -BuLi afforded -(silyl)lithiobenzene , which was reacted with (alkoxy)diarylboranes to form borate intermediates . Treatment of with chlorotrimethylsilane formed -(alkoxysilyl)(diarylboryl)benzenes . The C-O bond in was activated by intramolecular interaction between the oxygen atom and the boron atom.

Assessment of organic micropollutants occurrence in treated wastewater using heat shock protein 47 stress responses in Chinese hamster ovary cells and GC/MS-based non-target screening.

Combining bioassays and analytical chemistry screening is a powerful approach to assess organic micropollutants which are the main contributors to toxic potential in complex mixtures of treated wastewater (TWW). The aim of this study was to perform a comprehensive toxicity assessment of treated effluents using stress response bioassays and then to assess the occurrence of the organic micropollutants which were responsible for this biological response using gas chromatography coupled with a mass spectrometry detector (GC/MS). Results showed that TWW samples induced significant stress response on Chinese hamster ovary cells, stably transfected with heat shock protein 47 promoter, at 0.

Synthesis of a Pentacene-Type Silaborin via Double Dehydrogenative Cyclization of 1,4-Diboryl-2,5-disilylbenzene.

A new pentacene-type silaborin, in which three benzene rings are bridged by silicon and boron atoms, has been synthesized and characterized by using NMR spectroscopy and X-ray crystallographic analysis. The precursor, 1,4-bis(dimesitylboryl)-2,5-bis(phenylsilyl)benzene (4), was prepared by stepwise introduction of a silyl group and a boryl group to a benzene ring starting from 1,4-dibromobenzene. Double cyclization of 4 proceeds by a H-Mes exchange and a B-H/C-H dehydrogenative condensation to afford pentacene-type silaborin 5.

Quantification of Groundwater - Saline Surface Water Interaction in a Small Coastal Plain in North-East Tunisia using Multivariate Statistical Analysis and Geophysical Method.

  Amultivariate statistical analysis used with geophysical investigation enabled the assessment of interaction between saline surface water and groundwater in the coastal plain of Wadi Al Ayn and Daroufa in CapBon peninsula, north-east Tunisia. The application of the Principal Component Analysis (PCA) identified the end members which contribute to groundwater recharge: the wastewater infiltrated from Wadi Al Ayn, the oilfield brine infiltrated to the aquifer through the sandy bed of Wadi Al Ayn, the intruded seawater near Wadi Daroufa in the downstream region and the fresh groundwater flowing from the upstream region. The contribution of wastewater in groundwater recharge varies from 1.

Effects of metal pollution on sediments in a highly saline aquatic ecosystem: case of the Moknine continental Sebkha (eastern Tunisia).

Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assessed by means of enrichment factors (EFs) estimated against reference sediment located ≈70 km away from the Sebkha. The use of EFs is recommended as a reliable method for heavy metal contamination assessment, provided that (1) element contents are corrected following a careful normalization procedure, and (2) the reference sediment is unaffected by anthropogenic alterations. The degree of contamination was assessed by the modified contamination degree approach.

Synthesis of silicon-functionalized dibenzosilaborins by intramolecular B-H/C-H dehydrogenative cyclization and their tunable photophysical and chemical properties by silyl groups.

A bit borane: Silicon-functionalized dibenzosilaborins were prepared by intramolecular B-H/C-H dehydrogenative cyclization of o-(silyl)(hydroboryl)benzenes. The hydrosilyl derivative (X=H) can be converted into the fluorosilane (X=F) and chlorosilane (X=Cl). UV/Vis and fluorescence spectra are influenced by the functional groups X on the silicon atom through σ*-π* conjugation.

Identification of 6-octadecynoic acid from a methanol extract of Marrubium vulgare L. as a peroxisome proliferator-activated receptor γ agonist.

6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extract of Marrubium vulgare L. as an agonist of peroxisome proliferator-activated receptor γ (PPARγ). Fibrogenesis caused by hepatic stellate cells is inhibited by PPARγ whose ligands are clinically used for the treatment of diabetes.

Intramolecular H-Ar ligand exchange between silicon and boron: functionality transfer of Si-H to B-H.

o-C(6)H(4)(SiR(3-n)H(n))(BMes(2)) (1; R=Me, Ph; n=1, 2) undergo Mes-H (Mes=mesityl) ligand exchange between the silicon atom and the boron atom to form o-C(6)H(4)(SiMesR(3-n)H(n-1))(BMesH) (6) upon heating. The resulting hydroborane intermediates (6) immediately react with benzaldehyde to afford their corresponding benzyloxyboranes (5). A DFT study of model compounds reveals the transition states of the ligand exchange.

Synthesis, structure and reactions of triarylgermyl anion with alpha,delta-ambiphilic character.

Benzosilagermacyclobutene bearing two Ar groups on the germanium atom [Ar = o-(fluorodimethylsilyl)phenyl] undergoes cleavage of the Ge-Si bond with KF in the presence of a cryptand to form Ar(3)Ge(-)[K(+)(cryptand)] with alpha,delta-ambiphilic character consisting of the germyl anion center and the fluorosilyl moieties. In the presence of LiBPh(4).3dme or BF(3).

Synthesis of B/Si bidentate Lewis acids, o-(Fluorosilyl)(dimesitylboryl)benzenes, and their fluoride ion affinity.

o-(Fluorosilyl)(dimesitylboryl)benzenes have been prepared as colorless crystals by reacting fluorodimesitylborane with o-(fluorodimethylsilyl)phenyllithium and o-(fluorodiphenylsilyl)phenyllithium. The o-(fluorosilyl)(dimesitylboryl)benzenes serve as B/Si bidentate Lewis acid and efficiently capture fluoride ion from potassium fluoride in the presence of [2.2.