UV-visible Absorption Studies of Tetrachloro-p-benzoquinone and Tertiary Amines Charge Transfer Complexes in Trichloromethane

The spectophotometry of charge transfer (CT) complexes of tetrachloro-p-benzoquinone(TCB) with tertiary amine [triethylamine (TEA), triphylamine (TPA), N,N-dimethylphenylamine(DMPA), N-ethylcarbazole (ECZ)] have been studied in dichloromethane in UV-visible region.The CT complexes parameter, molar ratio of reactAnts in complex, molar extinction coefficient equilibrium constant KCT, free energy G and dissociation energy of the CT complex excited stateE, have also been estimated and discussed.

SOLVENT EXTRACTION OF Fe(Ⅲ) FROM SULFATE SOLUTIONS WITH TERTIARY AMINE

The tertiary amine can be used to extract Fe(Ⅲ) very effectively in the pH range resulting in partial hydrolysis of Fe^(3+) ions.The iron extracted into the organic phase can be stripped rather easily with dilute H_2SO_4 or even with H_2O.Fe(Ⅲ) is extracted into the tertiary amine sulfate solution in the form of[(R_3NH)_2Fe(OH)(SO_4)_2]_2 complex by adduct formation.Equa- tion was derived to represent the chemical reactions involved during extraction.From the infrared spectrum studies on the extraction species in waxy solid form separated from the so- lution,sulfate group is a bidentate ligand to the iron atom.The extraction species has been considered to contain (FeOH)_2 unit based on the ultra violet spectra.The possible structure of the extraction species has been proposed.

Enhancing CO_(2)capture of an aminoethylethanolamine-based non-aqueous absorbent by using tertiary amine as a proton-transfer mediator:From performance to mechanism

Non-aqueous absorbents(NAAs)have attracted increasing attention for CO_(2)capture because of their great energy-saving potential.Primary diamines which can provide high CO_(2)absorption loading are promising candidates for formulating NAAs but suffer disadvantages in regenerability.In this study,a promising strategy that using tertiary amines(TAs)as proton-transfer mediators was proposed to enhance the regenerability of an aminoethylethanolamine(AEEA,diamine)/dimethyl sulfoxide(DMSO)(A/D)NAA.Surprisingly,some employed TAs such as N,N-diethylaminoethanol(DEEA),N,N,N’,N’’,N’’-pentamethyldiethylenetriamine(PMDETA),3-dimethylamino-1-propanol(3DMA1P),and N,N-dimethylethanolamine(DMEA)enhanced not only the regenerability of the A/D NAA but also the CO_(2)absorption performance.Specifically,the CO_(2)absorption loading and cyclic loading were increased by about 12.7%and 15.5%-22.7%,respectively.The TA-enhanced CO_(2)capture mechanism was comprehensively explored via nuclear magnetic resonance technique and quantum chemical calculations.During CO_(2)absorption,the TA acted as an ultimate proton acceptor for AEEA-zwitterion and enabled more AEEA to form carbamate species(AEEACOO-)to store CO_(2),thus enhancing CO_(2)absorption.For CO_(2)desorption,the TA first provided protons directly to AEEACOO-as a proton donor;moreover,it functioned as a proton carrier and facilitated the low-energy step-wise proton transfer from protonated AEEA to AEEACOO-.Consequently,the presence of TA made it easier for AEEACOO-to obtain protons to decompose,resulting in enhanced CO_(2)desorption.In a word,introducing the TA as a proton-transfer mediator into the A/D NAA enhanced both the CO_(2)absorption performance and the regenerability,which was an efficient way to“kill two birds with one stone”.

Recent advances in tertiary amine Lewis base-promoted cycloadditions of allenoates

Lewis base-catalyzed annulations of allenoates have been one of the most powerful synthetic strategies for the synthesis of various valuable cycles,especially in the preparation of biologically active natural products and pharmaceuticals.Generally,the effective Lewis bases mainly include tertiary phosphine,NHC and tertiary amine catalysts,among those catalysis,tertiary amine Lewis bases have proven to be effective catalysts for a range of synthetic transformations.In the past decades,tremendous progress in-volving tertiary amines-promoted cycloaddition of allenoates has been made in the chemoselective con-struction of valuable motifs.This review describes a comprehensive and updated summary of tertiary amine Lewis base-promoted annulation reactions of allenoates.Diverse reactivities,chemoselectivties and detailed reaction mechanisms will be highlighted in this review.

Olefin-linked covalent organic frameworks with twisted tertiary amine knots for enhanced ultraviolet detection

Though Olefin-linked covalent organic frameworks(oCOFs)possess excellentπ-electron delocalization,the barely reversible olefin linkage brings challenges for oCOFs’synthesis and functionalization.Here,we synthesize new oCOFs with tertiary amine knots which have twisted configuration and electron-donating nature.Investigation into the structural variation and photoelectric performance shows that the twisted configuration of oCOF-TFPA could favor to the intramolecular charge transfer process and reduce the pos-sibility of aggregation-caused quenching.Photoelectrical measurements and electric band structure cal-culation both verify the superiority of this oCOFs’structure in photoelectric sensing.

Transalkylation of N-methyl tertiary amines with 3,4-dibromobutenolides

The selective transalkylation of N-methyl tertiary amines with 3,4-dibromobutenolides is described. The N-methyl group of the parent tertiary amines was replaced by alkenyl units of the butenolides; and a series of butenolide-containing tertiary enamines were obtained in moderate to good yields. Interestingly, the product 2b has shown a promising anticancer activity against HeLa cell lines （IC50 = 0.19μmol/L）.