The 143 and 300 K polymorphs of hexa­methyl­enetetraminium 2,4-di­nitro­phenolate monohydrate

The title compound, 3,5,7-tri­aza-1-azoniatri­cyclo­[3.3.1.1^3,7]­decane 2,4-di­nitro­phenolate monohydrate, C₆H₁₃N₄⁺·C₆H₃N₂O₅⁻·H₂O, the 1:1 hydrate adduct of hexa­methyl­enetetr­amine (HMT) and 2,4-di­nitro­phenol, undergoes a temperature phase transition. In the room-temperature phase, the adduct crystallizes in the monoclinic P2₁/m space group, whereas in the low-temperature phase, the adduct crystallizes in the triclinic P space group. This phase transition is reversible, with the transition temperature at 273 K, and the phase transition is governed by hydrogen bonds and weak interactions. In both these temperature-dependent polymorphs, the crystal structure is alternately layered with sheets of hexa­methyl­enetetr­amine and sheets of di­nitro­phenol stacked along the c axis. The hexa­methyl­enetetr­amine and di­nitro­phenol moieties are linked by intermolecular hydrogen bonds. The water mol­ecule in the adduct plays an important role, forming O—H⋯O hydrogen bonds which, together with C—H⋯O hydrogen bonds, bridge the adducts into molecular ribbons. Extra hydrogen bonds and weak interactions exist for the low-temperature polymorph and these interconnect the molecular ribbons into a three-dimensional packing structure. Also in these two temperature-dependent polymorphs, di­nitro­phenol acts as a hydrogen-bond acceptor and HMT acts as a hydrogen-bond donor.     

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.     

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.     

Separation and purification of 90Sr from PUREX HLLW using N,N,N′,N′-tetra(2-ethylhexyl) diglycolamide

This paper describes a method for the separation and purification of ⁹⁰Sr from PUREX–HLLW employing solvent extraction and precipitation techniques. 30 % TBP in n-dodecane was used for the removal of residual uranium, plutonium and neptunium from HLLW. Trivalent actinides and lanthanides were subsequently removed using N,N,N’,N’-tetra(2-ethylhexyl) diglycolamide (TEHDGA, 0.20 M in 30 % isodecyl alcohol and n-dodecane). ⁹⁰Sr was selectively extracted from actinides and lanthanides depleted HLLW using 0.3 M TEHDGA in 5 % isodecyl alcohol and dodecane. Loaded strontium was stripped using 0.01 M HNO₃ and further purified by radiochemical precipitation technique after adding Fe and natural strontium as carriers. Based on the experimental results, a flow-sheet was formulated and mCi levels of ⁹⁰Sr recovered.     

trans-Bis(2-amino­pyridine-N)bis(O,O′-diiso­propyl di­thio­phosphato-S,S′)nickel(II)

In the title compound, [Ni(C₆H₁₄O₂PS₂)₂(C₅H₆N₂)₂], the coordination around the Ni atom, which lies on a crystallographic centre of symmetry, is octahedral with the S atoms from the di­thio­phosphate ligands occupying the equatorial positions, while the axial positions are occupied by the ring N atoms of the 2-amino­pyridine ligands. The mol­ecules form layers in the bc plane which are stacked in the direction of the a axis.     

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.     

The step dissociation constants of ethylenediamine-N,N′-diacetic-N,N′-dipropionic and ethylenediamine-N,N,N′,N′-tetrapropionic acids

The step dissociation constants of ethylenediamine-N,N′-diacetic-N,N′-dipropionic and ethylenediamine-N,N,N′,N′-tetrapropionic acids at 298.15 K and ionic strengths of 0.1, 0.5, and 1.0 (KNO₃) were determined potentiometrically. The results were extrapolated to zero ionic strength by the equation with one individual parameter. The thermodynamic constants of dissociation were calculated. The results are compared with the corresponding data on related compounds.     

Synthesis,characterization and SOD-like activities of manganese-containing complexes with N,N,N′,N′-tetrakis(2′-benzimidazolyl methyl)-1,2-ethanediamine (EDTB)

A series of manganese-containing mononuclear and binuclear model compounds of superoxide dismutase (SOD) coordinated by a polydentate ligand N,N,N′,N′-tetrakis(2′-benzimidazolyl methyl)-1,2-ethanediamine (EDTB) have been synthesized and characterized. The SOD-like activities of these complexes have been measured by means of modified nitroblue tetrazolium (NBT) photoreduction, and the rate constants k_Q of catalytic superoxide dismutation are in the range 6.96×10⁶–2.32×10⁷ l mol⁻¹ s⁻¹. In complex [Mn(EDTB)(Ac)](Ac)·C₂H₅OH the coordination environment around the manganese(II) ion can be described as a highly-distorted capped octahedron with an oxygen atom of the bidentate acetate ion at the capping site. This complex is the first example in which EDTB acts as a pentadentate ligand with one non-ligating benzimidazole group.     

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.

     

Bis(O,O′-diiso­propyl di­thio­phosphato-S,S′)(1,10-phenanthroline-N,N′)metal(II) complexes with cadmium(II) and iron(II)

The two title compounds, [M(C₆H₁₄O₂PS₂)₂(C₁₂H₈N₂)], where M = Cd^II and Fe^II, are isomorphous. Each compound has a crystallographic twofold axis of symmetry through the metal atom and the 1,10-phenanthroline mol­ecule. The central metal atom is coordinated to four S atoms from the two dithiophos­phate groups and two N atoms from the 1,10-phenanthroline ligand. The environment of the metal atom is a distorted octahedron.     

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。