55-86-7Relevant academic research and scientific papers
To be dinuclear or not: Z-DNA induction by nickel complexes
Spingier, Bernhard,Antoni, Philipp M.
, p. 6617 - 6622 (2007)
The left-handed Z-DNA has been identified as a gene regulating element. Therefore the generation of ZDNA through metal complexes might be an innovative way for the regulation of gene expression. Use of the new dinuclear complex N,N,N',N'-tetrakis-[2(3,5-dimethylpyrazol-l-yl)ethylJ-l,3propylenediamine- bis(nickel(II) dinitrate) (2) reversibly induced Z-DNA formation. However, when a 1:1 ratio of metal/dinucleating ligand was used as a control, the midpoint of the B- to Z-DNA transition was at the same nickel concentration as in case of the dinuclear complex. The novel mononuclear analogue, N-methyl-N,N-bis-[2(3,5- dimethylpyrazol-l-yl)ethyl]aminenickel(II)-dinitrate (3) was inducing the Z-DNA at a similar ratio versus nucleotides as free nickel(II) itself. For the first time, proton and nickel binding constants for the bis-[2-(pyrazol-lyl)ethyl] amine ligand system are reported and discussed. Both nickel complexes 2 and 3 were structurally characterized by single crystal analysis. Furthermore, the synthesis of the two new ligands, N,N,N',N,'-tetrakis-[2-(3,5-dimethylpyrazol-l- yl)ethyl]-l,2-propylenediamine (4) and N-methyl-N,N-bis-[2(3,5-dimethylpyrazol- l-yl)ethyl]amine (5) is described. The two major synthetic pathways leading to polypyrazoyl amines in general are critically discussed with respect to yield, reproducibility and handling of the intermediates.
Preparation of 1-amino-4-methylpiperazine
Kushakova,Chernobroviy,Kuznetsov,Garabadgiu
, p. 1546 - 1549 (2004)
The selectivity of the formation of N-di(2-chloroethyl)methylamine in reactions with various chlorinating agents has been investigated and the optimum chlorinating agent has been found. 1-Amino-4-methylpiperazine has been obtained for the first time by the cyclization of N-di(2-chloroethyl)methylamine with aqueous hydrazine. A possible mechanism has been proposed for the cyclization reaction. 2004 Springer Science+Business Media, Inc.
Synthesis, structure, spectra and redox of Cu(II) complexes of chelating bis(benzimidazole) - Thioether ligands as models for electron transfer blue copper proteins
Vaidyanathan,Balamurugan,Sivagnanam,Palaniandavar
, p. 3498 - 3506 (2001)
The tridentate ligand 1,5-bis(benzimidazol-2-yl)-3-thiapentane (L1) with N2S donor set forms the complex [Cu(L1)-(H2O)Cl]Cl 1a and the linear quadridentate ligand 1,8-bis(benzimidazol-2-yl)-3,6-dithiaoctane (L2) with N2S2 donor set forms the complexes [Cu(L2)](ClO4)2·2H2O 2a and [Cu(L2)(NO3)]NO3 2b. The linear pentadentate ligand 1,11-bis(pyrid-2-yl)-3,6,9-trithiaundecane (L3) with N2S3 donor set forms the complex [Cu(L3)](ClO4)2 3. The perchlorate complex [Cu(L4)](ClO4)2·2CH3CN 4 of the pentadentate ligand,N,N-bis(benzimidazol-2-ylmethylthioethyl)methyl-amine (L4) with N3S2 donor set has also been isolated. In 1a Cu(II) is coordinated to the two benzimidazole nitrogens and thioether sulfur of the ligand L1, a chloride ion and a water molecule. The coordination geometry around copper is intermediate between trigonal bipyramidal and square pyramidal geometries and is better described as trigonal bipyramidal distorted square based pyramidal (TBDSBP) with the sulfur and nitrogen atoms and the chloride ion in the equatorial positions and the oxygen of water in the apical position. The coordination geometry around copper(II) in 2b is best described as trigonal bipyramidal, with both the thioether sulfur atoms [Cu-S(1), 2.529(5) and Cu-S(2), 2.438(6) A] and one of the oxygen atoms of the nitrate ion [Cu-O(1), 2.066(13) A] constituting the trigonal plane and both the benzimidazole nitrogens [Cu-N, 1.985(14) and 1.953(13) A] occupying the axial positions. The bulky benzimidazole moieties of the ligand prevent the other nitrate ion from coordinating and favours trigonal bipyramidal geometry in spite of the presence of two six-membered chelate rings. In 4 the coordination plane of Cu(II) is comprised of two benzimidazole nitrogens, one thioether sulfur and N-methyl substituted amine nitrogen atom with the other thioether sulfur atom coordinated axially. The coordination geometry is best described as trigonal bipyramidal distorted square based pyramidal (TBDSBP). The ligand field and EPR spectra of 1a, 2a and 2b are consistent with trigonal bipyramidal geometry in the solid state, whereas two ligand field bands in solution and an axial EPR spectrum in frozen solution were observed suggesting a change in coordination geometry to a square-based one on dissolution. The complexes 3 and 4 exhibit only one ligand field band in the solid state and axial EPR spectrum consistent with a square based geometry. All the complexes exhibit an intense S(σ)→Cu(II) CT band in the range 330-380 nm and a high positive CuII/CuI redox potential.
Synthesis and characterisation of ruthenium dihydrogen complexes and their reactivity towards B-H bonds
Choi, Jong-Hoo,Schloerer, Nils E.,Berger, Josefine,Prechtl, Martin H. G.
, p. 290 - 299 (2014)
In this paper the synthesis and characterisation of ruthenium dihydrogen complexes bearing rigid aliphatic PNP pincer-type ligands are described. As one result hydride complexes were synthesised in good to high yields by a one-pot direct hydrogenation reaction. As another finding the dihydrogen complex, stabilised with a N-Me group in the ligand frame, can be converted with dimethylamine borane into a rare σ-boron complex [RuH2(BH 3)(Me-PNP)] with rapid B-N decoupling. Additionally, we present the first mass spectrometric analysis of the synthesised σ-complexes via liquid injection field desorption/ionisation technique (LIFDI-MS).
Mass spectral studies of silyl derivatives of partially hydrolyzed products of nitrogen mustards: Important markers of nitrogen mustard exposure
Chandra, Buddhadeb,Sinha Roy, Kanchan,Shaik, Mahabul,Waghmare, Chandrakant,Palit, Meehir
, (2020/01/21)
Rationale: Nitrogen mustards (NMs) are vesicant class of chemical warfare agents. From the viewpoint of the Chemical Weapons Convention partially hydrolyzed products of nitrogen mustards (pHpNMs) are considered as important markers of nitrogen mustard exposure. The detection of pHpNMs from biological or environmental samples is highly useful for obtaining forensic evidence of exposure to NMs. Methods: Gas chromatography interfaced with tandem mass spectrometry (GC/MS/MS) is a widely used tool for the identification and sensitive detection of metabolites of NMs in complex matrices. The pHpNMs were derivatized using silylating agents as they are highly polar and non-amenable to GC. The mass spectral studies of these silyl derivatives of pHpNMs were performed using GC/MS/MS in both electron ionization (EI) and chemical ionization (CI) mode. Results: Various approaches have been proposed to assess the fragmentation pathways of the trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBDMS) derivatives of pHpNMs. All the proposed fragmentation pathways were based on the product and/or precursor ion scanning of corresponding ions in both EI and CI mode. In the case of EI, most of the fragmentation pathways involved either α-cleavage or inductive cleavage. Conclusions: This is the first report on the MS study of the silyl derivatives of pHpNMs. The study of the two different derivatives of pHpNMs using both EI- and CI-MS provides a reliable, unambiguous identification of pHpNMs in complex environmental and biomedical matrices (such as plasma and urine) during any verification activities.
TIN COMPOUND, TIN PRECURSOR COMPOUND FOR FORMING A TIN-CONTAINING LAYER, AND METHODS OF FORMING A THIN LAYER USING THE SAME
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Paragraph 0034, (2020/08/05)
A tin compound, a tin precursor compound for forming a tin-containing layer, and a method of forming a thin layer, the tin compound being represented by Formula 1: wherein R1, R2, R3, R4, R5, R6, and R7 are each independently hydrogen, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 or 4 carbon atoms.
Rational design of an organocatalyst for peptide bond formation
Handoko,Satishkumar, Sakilam,Panigrahi, Nihar R.,Arora, Paramjit S.
supporting information, p. 15977 - 15985 (2019/10/11)
Amide bonds are ubiquitous in peptides, proteins, pharmaceuticals, and polymers. The formation of amide bonds is a straightforward process: amide bonds can be synthesized with relative ease because of the availability of efficient coupling agents. However, there is a substantive need for methods that do not require excess reagents. A catalyst that condenses amino acids could have an important impact by reducing the significant waste generated during peptide synthesis. We describe the rational design of a biomimetic catalyst that can efficiently couple amino acids featuring standard protecting groups. The catalyst design combines lessons learned from enzymes, peptide biosynthesis, and organocatalysts. Under optimized conditions, 5 mol % catalyst efficiently couples Fmoc amino acids without notable racemization. Importantly, we demonstrate that the catalyst is functional for the synthesis of oligopeptides on solid phase. This result is significant because it illustrates the potential of the catalyst to function on a substrate with a multitude of amide bonds, which may be expected to inhibit a hydrogen-bonding catalyst.
Molecular Routes to Two-Dimensional Metal Dichalcogenides MX2 (M = Mo, W; X = S, Se)
Brune, Veronika,Hegemann, Corinna,Mathur, Sanjay
, p. 9922 - 9934 (2019/08/26)
New synthetic access to two-dimensional transition metal dichalcogenides (TMDCs) is highly desired to exploit their extraordinary semiconducting and optoelectronic properties for practical applications. We introduce here an entirely novel class of molecular precursors, [MIV(XEtN(Me)EtX)2] (MIV = MoIV, WIV, X = S, Se), enabling chemical vapor deposition of TMDC thin films. Molybdenum and tungsten complexes of dianionic tridentate pincer-type ligands (HXEt)2NR (R = methyl, tert-butyl, phenyl) produced air-stable monomeric dichalcogenide complexes, [W(SEtN(Me)EtS)2] and [Mo(SEtN(Me)EtS)2], displaying W and Mo centers in an octahedral environment of 4 S and 2 N donor atoms. Owing to their remarkable volatility and clean thermal decomposition, both Mo and W complexes, when used in the chemical vapor deposition (CVD) process, produced crystalline MoS2 and WS2 thin films. X-ray diffraction analysis and atomic-scale imaging confirmed the phase purity and 2D structural characteristics of MoS2 and WS2 films. The new set of ligands presented in this work open ups convenient access to a scalable and precursor-based synthesis of 2D transition metal dichalcogenides.
COMPOSITIONS AND METHODS FOR THE TREATMENT OF SEVERE PAIN
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Paragraph 0109-0110, (2015/03/31)
The invention relates to the compounds of formula I or its pharmaceutical acceptable salts, as well as polymorphs, solvates, enantiomers, stereoisomers and hydrates thereof. The pharmaceutical compositions comprising an effective amount of compounds of formula I, and methods for the treatment of severe pain may be formulated for oral, buccal, rectal, topical, transdermal, transmucosal, intravenous, parenteral administration, syrup, or injection. Such compositions may be used to treatment of postoperative pain, cancer pain, kidney stones pain, fractures, local pain, chronic pain, chemotherapy induced pain, neuropathic pain, post herpetic neuralgia, neuralgia, motor neurone disease, diabetic neuropathy, postherpetic neuralgia, injury, post-operative pain, osteoarthritis, rheumatoid arthritis, multiple sclerosis, spinal cord injury, migraine, HIV related neuropathic pain, cancer pain and lower back pain.
COMPOUNDS AND METHODS for the inhibition of HDAC
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Paragraph 0395-0396, (2015/11/24)
Disclosed are compounds having the formula: wherein X1, X2, X3, R1, R2, R3, R4, Y, A, Z, L and n are as defined herein, and methods of making and using the same.
