Cyclopalladation of N,N,N′,N′-tetramethylisophthalthioamide

Summary N,N,N,N-Tetramethylisophthalthioamide (Hmpt) was cyclopalladated with PdCl₂ in hot dimethylsulphoxide to give [PdCl(mpt)]. The structure was determined by X-ray analysis. The thioamide is metallated at C(2) to act as an S528-01C528-02S tridentate anionic ligand. There is appreciable steric repulsion between the benzene ring H(4, 6) and the dimethylamino groups. The hydrogens and the methyl groups mutually deviate from the coordination plane in opposite directions. The stability of the fused 5,5-membered chelate ring formed by the S528-03C528-04S ligand seems to overcome the steric hindrance. Derivatives were prepared by replacement of the chloride ion with iodide, diethyldithiocarbamate, 4-tert-butylpyridine, or tri-n-butylphosphine, and characterized spectroscopically. The S528-05C528-06S-fused chelate ring was maintained in these derivatives.     

Vibrational spectra of N,N-dimethyl/diethylaniline,N,N,N′,N′-tetramethyl/tetraethyl-p-phenylenediamine and N,N,N′,N′-tetramethyl/tetraethylbenzidine derivatives

The ground state and protonated state (quaternized salt) vibrational spectra (200–1800 cm⁻¹) of the title amines are reported for various ring and/or methyl deuterated derivatives. Complete assignments are proposed and compared to those established for the parent hydrocarbons, benzene and biphenyl, and for the parent primary amines, aniline, p-phenylenediamine and benzidine. The electronic distribution, N(n)→ring(π) charge-transfer character and inductive effects are characterized from a vibrational point of view. Finally changes in the vibrational and electronic conformation upon protonation of the nitrogen atom are discussed. These results provide a fundamental basis for the vibrational investigation of excited states and reactive transients of aromatic amines.     

N-Lithio-N,N′,N″,N″-tetramethyldiethylenetriamine and N′-Lithio-N,N,N″,N″-tetramethyldiethylenetriamine; Oxidative Coupling of Aminomethyllithium Derivatives

N-lithio-N,N′,N″,N″-tetramethyldiethylenetriamine (I-Li) is formed from 2,5,8,11-tetramethyl-2,5,8,11-tetraazadodecane (III) or from 2,5,8,11,14,17-hexamethyl-2,5,8,11,14,17-hexaazaoctadecane (IV) with n-BuLi or sec-BuLi, respectively, its isomer N′ -lithio-N,N,N″,N″,-tetramethyldiethylene-triamine (II-Li) from tris(2-dimethylaminoethyl)amine (V) with n-BuLi. IV results from treatment of N-lithiomethyl-N,N′,N″,N″-tetramethyldiethylenetriamine (PMDTA-Li) with 1,2-dibromoethane.     

Kristallstruktur von N,N,N′,N′-Tetraisopropyl-p-phenylen-diammonium-dichlorid und-bis(tetrachloroaluminat)

Summary Protonation of the sterically overcrowded N,N,N,N-tetraisopropyl-p-phenylenediamine leads to a significant shortening of the C-N bond lengths of 7 pm as well as to a widening of the phenyl ipso-angle to 122°. All structural changes can be attributed to the twisted diisopropylammonium substituents and their electron acceptor properties.

     

Sensitive Spectrophotometric Determination of Benzoylperoxide with N,N,N′,N′-Tetramethyl-p-phenylenediamine

Abstract

A highly sensitive spectrophotometric determination of benzoylperoxide (BPO) based on the color developing reaction between N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) and BPO in the presence of cerium(IV) in weakly acidic media is proposed. The calibration graph is linear in the range 0–6000 ng BPO per 10 ml with an apparent molar absorptivity of 4.73 × 10⁵ 1 mol^?1 cm-1 at 612 nm. The proposed method is about 50-fold more sensitive than N-ethyl-2-naphthylamine (NENA), and application to assays of flour is described.     

N,N,N′,N′-四苄基乙二胺与氯化铜的络合物

Patel^[1]用无水氯化铜和N,N,N′,N′-四苄基乙二胺(简写为TBEn)制得Cu(TBEn)Cl₂和Cu(TriBEn)Cl₂(TriBEn,N,N,N′-三苄基乙二胺)固体络合物。本文报道对patel合成TBEn方法的改进和用水含氯化铜的TBEn制得和Cu(TBEn)Cl₂和Cu(TriBEn)Cl₂固体络合物的热分解结果。     

Vibrational study of N,N,N′,N′-tetramethyl-p-phenylenediamine and its radical cation

The i.r. and Raman spectra of N,N,N′,N′-tetramethyl-p-phenylenediamine and the perchlorate salt of its radical cation have been recorded. The frequencies of the fundamental vibrations of the neutral molecule and the radical ion have been computed using force constants transferred from smaller molecules. The observed spectral bands have been assigned and the ionization band shifts have been discussed. Most of the significant band shifts have been observed in the 1700-1300 cm⁻¹ range. The calculations showed that they are primarily due to the variation of the bond strengths of the ring CC and ring-N bonds.     

Poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide, N,N,N′,N′-tetrachlorobenzene-1,3-disulfonamide, poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide, and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide catalyzed formylation of amines and alcohols using ethyl formate under microwave irradiation

A simple, rapid, and efficient procedure for formylation of primary and secondary amines and alcohols using ethyl formate catalyzed with poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide (PCBS), N,N,N′,N′-tetrachlorobenzene-1,3-disulfonamide (TCBDA), poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide (PBBS) and also N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide (TBBDA) was adopted. The reactions were performed under microwave irradiation with high yields.     

Improved Syntheses of N‐Desmethylcitalopram and N,N‐Didesmethylcitalopram

An improved and efficient synthesis of N‐desmethylcitalopram (2) and N,N‐didesmethylcitalopram (3) is presented. The method involved N‐demethylation of citalopram (1) using 1‐chloroethyl chloroformate to give 2 in 87% yield. Synthesis of 3 was accomplished by alkylation of 8 with 1‐(3‐bromopropyl)‐2,2,5,5‐tetramethyl‐1‐aza‐2,5‐disilacyclopentane (9).     

The rare earths—XCI: Lanthanide(III) complexes of N,N′-dimethylethylenediamine and N,N,N′,N′-tetramethylethylenediamine

Under carefully controlled experimental conditions and with the maintenance of completely anhydrous systems, crystalline lanthanide complexes with nitrogen-donor ligands N,N′-dimethylethylenediamine (dmed) and N,N,N′,N′-tetramethylethylenediamine (tmed) have been isolated. Stoichiometric compositions of the products are Ln(dmed)₂Cl₃ (Ln = Sm, Er, Yb), Ln(dmed)₂(NO₃)₃ (Ln = Pr, Sm), Gd(dmed)(NO₃)₃, Ln(tmed)Cl₃ (Ln = La, Pr, Nd, Sm, Ho, Er) and Ln(tmd)(NO₃)₃·xCH₃CN (Ln = Nd, Er, Ho; x = 0, 1). Calorimetric studies indicate that the dmed complexes do not form in a stepwise fashion in acetonitrile, but rather that higher-order species form in solution.     

PVT properties of N,N,N′,N′-Tetraoctyl-3-oxapentanediamide (TODGA)

N,N,N??,N??-Tetraoctyl-3-oxapentanediamide (TODGA) is a versatile extractant for partitioning of fission products from highly active raffinate wastes. Its PVT properties are not available in literature. In this work, PVT properties of TODGA, estimated using group contribution method, are reported. A corresponding-states based equation as well as Wagner constants were also reported in the range of 273.15?K to critical temperature.