Influence of the configuration of the amine nitrogen atom on the efficiency of fluorescence of 4-aminonaphthalimide derivatives

The ligand molecule N10-(2′-mercaptoethanoyl)-2,2,5,5-tetramethyl-3,4-dithia-7,10-diazabicyclo[5.3.0]decane has been prepared and characterized by 1H and 13C NMR spectroscopy and by mass spectrometry. The protected analogue, N10-[(2′-triphenylmethylthio)ethanoyl]2,2,5,5-tetramethyl-3,4-dithia-7,10-diazabicyclo[5.3.0]decane dimethanol hemihydrate, was examined by the same techniques and also by X-ray crystallography. Crystals were triclinic, P-1, a = 11.125(2), b = 11.986(2), c = 13.562(3) Å, α = 103.54(3)°, β = 90.29(3)°, γ = 107.11(3)°, and Z = 2. The crystal was unstable in air at room temperature, so measurements were made on a crystal sealed in a tube that contained methanol vapour Intensities were measured with a Rigaku AFC6R diffractometer and monochromated CuKα radiation (λ = 1.54178 Å). The structure was solved by direct methods and refined to R = 0.1497, wR = 0.0655 based on 5000 independent reflections. The high residuals were caused by solvent disorder. Bond lengths and angles were normal. The reaction of the ligand with oxotrichlorobis(triphenylphosphine)rhenium(V) yielded an unexpected asymmetric complex, oxo(1,1-dimethyl-1,8-dimercapto-3,6-diazaoctan-7-onato-N3,N6,S1,S8) rhenium(V). Crystals were monoclinic, P21/n, a = 10.633(2), b = 11.221(2), c = 11.678(1) Å, β = 116.10(1)°, Z = 4. Intensities were measured with a Siemens P4 diffractometer and monochromated MoKα radiation (λ = 0.71073 Å). The structure was solved by the heavy atom method and refined to R = 0.0471, wR = 0.0340 based on 2866 unique reflections. Most bond lengths and angles were normal. The Re≡O distance of 1.681(5) Å was longer than normal. It is postulated that this was caused by competitive π bonding between the deprotonated amidic nitrogen atom and the rhenium atom, as shown by the short Re—N distance (1.997(6) Å) compared to the equivalent distance for the amine nitrogen atom (Re—N, 2.151(4) Å). Key words: N2S2 ligands, rhenium, crystal structure.

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N-Tris[(2-aminoethyl)-2-(diphenylphosphoryl) acetamide)] — novel CMPO tripodand: synthesis, extraction studies and luminescent properties of lanthanide complexes

Open Chemistry ◽

10.2478/s11532-011-0124-5 ◽

2012 ◽

Vol 10 (1) ◽

pp. 146-156 ◽

Cited By ~ 23

Author(s):

Elena Sharova ◽

Oleg Artyushin ◽

Alexander Turanov ◽

Vasilii Karandashev ◽

Svetlana Meshkova ◽

...

Keyword(s):

Nitrogen Atom ◽

Luminescent Properties ◽

Lanthanide Ions ◽

Acid Solutions ◽

Acidic Media ◽

Amine Nitrogen Atom ◽

Europium Complexes ◽

Amine Nitrogen ◽

Anionic Complexes ◽

Extraction Properties

AbstractA ligand system containing three carbamoylmethylphosphine oxide (CMPO) moieties attached to a tripodal platform with a central nitrogen atom has been synthesized for metal complexation and extraction from neutral and nitric acid solutions. Liquid-liquid extractions performed for Ln(III), both from neutral and acidic media, show excellent extraction properties which exceeded those for the known mono- and di-CMPO derivatives as well as the related tripodands. A considerable enhancement of the DLn values was observed in the presence of IL ([bmim][Tf2N]) in the organic phase towards lanthanide ions from 3M HNO3 solutions. The protonation of the central amine nitrogen atom of the ligand 1 in the acidic media provides also the effective extraction of the perrhenate anionic complexes. The europium complexes formed by mono- and tris-CMPO ligands in the solid state, as well as Eu(III) and Tb(III) complexes generated in solutions, possess intensive luminescence at 300K

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The Tertiary Amine Nitrogen Atom of Piperazine Sulfonamides as a Novel Determinant of Potent and Selective β3-Adrenoceptor Agonists

ChemMedChem ◽

10.1002/cmdc.200900292 ◽

2009 ◽

Vol 4 (12) ◽

pp. 2080-2097 ◽

Cited By ~ 6

Author(s):

Maria Grazia Perrone ◽

Laura Bleve ◽

Ernesto Santandrea ◽

Paola Vitale ◽

Mauro Niso ◽

...

Keyword(s):

Nitrogen Atom ◽

Tertiary Amine ◽

Amine Nitrogen Atom ◽

Amine Nitrogen ◽

Adrenoceptor Agonists

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Pyridine-4-carboxamidoxime N-oxide

IUCrData ◽

10.1107/s2414314620013358 ◽

2020 ◽

Vol 5 (10) ◽

Author(s):

Clifford W. Padgett ◽

Kirkland Sheriff ◽

Will E. Lynch

Keyword(s):

Crystal Structure ◽

Hydrogen Bonding ◽

Nitrogen Atom ◽

Hydrogen Bonds ◽

Oxygen Atom ◽

Metal Organic Frameworks ◽

Amine Nitrogen Atom ◽

Amine Nitrogen ◽

Compound C ◽

Metal Organic

Our work in the area of synthesis of metal–organic frameworks (MOFs) based on organic N-oxides led to the crystallization of pyridine-4-carboxamidoxime N-oxide. Herein we report the first crystal structure of the title compound, C6H7N3O2 [systematic name: (Z)-4-(N′-hydroxycarbamimidoyl)pyridine N-oxide]. The hydroxycarbamimidoyl group is essentially coplanar with the aromatic ring, r.m.s.d. = 0.112 Å. The compound crystallizes in hydrogen-bonding layers built from the formation of strong O—H...O hydrogen bonds between the oxime oxygen atom and the oxygen atom of the N-oxide, and the formation of N—H...O hydrogen bonds between one amine nitrogen atom and the N-oxide oxygen atom. These combined build R 3 4(24) ring motifs in the crystal. The crystal structure has no π–π interactions.

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Structure–activity studies of β-carbolines. 3. Crystal and molecular structures of methyl β-carboline-3-carboxylate

Canadian Journal of Chemistry ◽

10.1139/v85-458 ◽

1985 ◽

Vol 63 (10) ◽

pp. 2752-2756 ◽

Cited By ~ 13

Author(s):

Alastair K. S. Muir ◽

Penelope W. Codding

Keyword(s):

Nitrogen Atom ◽

Biological Response ◽

Benzodiazepine Receptor ◽

Carbonyl Oxygen ◽

Molecular Structures ◽

Side Chain ◽

Amine Nitrogen Atom ◽

Amine Nitrogen ◽

Crystal And Molecular Structures ◽

Affinity Ligand

The crystal and molecular structures of methyl β-carboline-3-carboxylate, C13H10N2O, a high-affinity ligand for the benzodiazepine receptor, are reported. This candidate for the endogenous ligand for the receptor produces a biological response that is opposite to the anxiety-reducing effect of the usual agonists of the receptor and is, therefore, classified as an inverse-agonist. The space group is P21/c with a = 11.4866(9), b = 5.8091(3), c = 32.417(3) Å, β = 97.111(3)°, Z = 8. In both of the unique molecules, the ester side chain has an extended conformation and is coplanar with the β-carboline moiety. The carbonyl oxygen atom and the aromatic nitrogen atom are cis and form a three-centre hydrogen bond to the amine nitrogen atom of the other molecule in the asymmetric unit.

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Protonation site for anilines in aqueous media

Journal of the Serbian Chemical Society ◽

10.2298/jsc0202111p ◽

2002 ◽

Vol 67 (2) ◽

pp. 111-113 ◽

Cited By ~ 5

Author(s):

Alexei Pankratov ◽

Inna Uchaeva

Keyword(s):

Nitrogen Atom ◽

Aqueous Medium ◽

Gaseous Phase ◽

Aqueous Media ◽

Aminobenzoic Acid ◽

Amine Nitrogen Atom ◽

Protonation Site ◽

Amine Nitrogen ◽

Aminobenzoic Acids ◽

Phase Proceeds

By means of the PM3 method it has been shown that the protonation of 2-, 3 4-methoxyanilines, 4-methylthioaniline, 2-, 3-, 4-aminobenzoic acids, 2 3-, 4-nitroanilines in the gaseous phase proceeds via the amine nitrogen atom. The same result, attributed to the aqueous medium, was obtained for 4-methoxyaniline, 4-aminobenzoic acid and 4-nitroaniline.

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Pyclen-Based Ligands Bearing Pendant Picolinate Arms for Gadolinium Complexation

10.26434/chemrxiv.13204070.v1 ◽

2020 ◽

Author(s):

Gwladys Nizou ◽

Enikő Molnár ◽

Nadège Hamon ◽

Ferenc K. Kalman ◽

Olivier Fougere ◽

...

Keyword(s):

Water Molecule ◽

Metal Ion ◽

Water Exchange ◽

Picolinic Acid ◽

Exchange Process ◽

High Water ◽

Quantum Yields ◽

Amine Nitrogen Atom ◽

Water Binding ◽

Amine Nitrogen

We report the synthesis of two pyclen-based regioisomer ligands (pyclen = 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca1(15),11,13-triene) functionalized with picolinic acid pendant arms either at positions 3,9-pc2pa (L5) or 3,6-pc2pa (L6) of the macrocyclic fragment. The ligands were prepared by regiospecific protection of one of the amine nitrogen atom of the macrocycle using Boc and Alloc protecting groups, respectively. The X-ray structure of the Gd(III) complex of L5 contains trinuclear [(GdL5)3(H2O)3] 3+ entities in which the monomeric units are joined by 2- 1 : 1 carboxylate groups. However, the 1H and 89Y NMR spectra of its Y(III) analogue support the formation of monomeric complexes in solution. The Tb(III) complexes are highly luminescent, with emission quantum yields of up to 50% for [TbL5] + . The luminescence lifetimes recorded in H2O and D2O solutions indicate the presence of a water molecule coordinated to the metal ion, as also evidenced by the 1H relaxivities measured for the Gd(III) analogues. The Gd(III) complexes present very different exchange rates of the coordinated water molecule (kex 298 = 87.1 and 1.06 106 s -1 for [GdL5] + and [GdL6] + , respectively). The very high water exchange rate of [GdL5] + is associated to the steric hindrance originated by the coordination of the ligand around the water binding site, which favors a dissociatively activated water exchange process. The Gd(III) complexes present rather high thermodynamic stabilities (logKGdL = 20.47 and 19.77 for [GdL5] + and [GdL6] + , respectively). Furthermore, these complexes are remarkably inert with respect to their acid-assisted dissociation, in particular the complex of L5.

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The Amine Group as Halogen Bond Acceptor in Cocrystals of Aromatic Diamines and Perfluorinated Iodobenzenes

Crystals ◽

10.3390/cryst11050529 ◽

2021 ◽

Vol 11 (5) ◽

pp. 529

Author(s):

Erik Uran ◽

Luka Fotović ◽

Nikola Bedeković ◽

Vladimir Stilinović ◽

Dominik Cinčić

Keyword(s):

Hydrogen Bond ◽

Primary Amine ◽

Halogen Bond ◽

Halogen Bonds ◽

Hydrogen Atoms ◽

Amine Nitrogen Atom ◽

Aromatic Diamines ◽

Amine Nitrogen ◽

Amine Hydrogen ◽

Amine Groups

In order to study the proclivity of primary amine groups to act as halogen bond acceptors, three aromatic diamines (p-phenylenediamine (pphda), benzidine (bnzd) and o-tolidine (otol)) were cocrystallised with three perfluorinated iodobenzenes (1,4-tetrafluorodiiodobenzene (14tfib), 1,3-tetrafluorodiiodobenzene (13tfib) and 1,3,5-trifluorotriiodobenzene (135tfib)) as halogen bond donors. Five cocrystals were obtained: (pphda)(14tfib), (bnzd)(13tfib)2, (bnzd)(135tfib)4, (otol)(14tfib) and (otol)(135tfib)2. In spite of the variability of both stoichiometries and structures of the cocrystals, in all the prepared cocrystals the amine groups form exclusively I···N halogen bonds, while the amine hydrogen atoms participate mostly in N–H⋯F contacts. The preference of the amine nitrogen atom toward the halogen bond, as opposed to the hydrogen bond (with amine as a donor), is rationalised by means of computed hydrogen and halogen bond energies, indicating that the halogen bond energy between a simple primary amine (methylamine) and a perfluorinated iodobenzene (pentafluoroiodobenze ne) is ca. 15 kJ mol−1 higher than the energy of the (H)NH∙∙∙NH2 hydrogen bond between two amine molecules.

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Geometrical variations of two manganese(II) complexes with closely related quinoline-based tripodal ligands

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989021009786 ◽

2021 ◽

Vol 77 (10) ◽

Author(s):

Steven T. Frey ◽

Jasper G. Ballot ◽

Allison Hands ◽

Haley A. Cirka ◽

Katheryn C. Rinaolo ◽

...

Keyword(s):

Hydrogen Bonding ◽

Nitrogen Atom ◽

Oxygen Atom ◽

Crystal Packing ◽

Distorted Octahedral Geometry ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Amine Nitrogen ◽

Distorted Octahedral ◽

Oxygen Atoms

Structural analyses of the compounds di-μ-acetato-κ4 O:O′-bis{[2-methoxy-N,N-bis(quinolin-2-ylmethyl)ethanamine-κ4 N,N′,N′′,O]manganese(II)} bis(tetraphenylborate) dichloromethane 1.45-solvate, [Mn2(C23O2)2(C23H23N3O)2](C24H20B)·1.45CH2Cl2 or [Mn(DQMEA)(μ-OAc)2Mn(DQMEA)](BPh4)2·1.45CH2Cl2 or [1](BPh4)2·1.45CH2Cl2, and (acetato-κO)[2-hydroxy-N,N-bis(quinolin-2-ylmethyl)ethanamine-κ4 N,N′,N′′,O](methanol-κO)manganese(II) tetraphenylborate methanol monosolvate, [Mn(CH3COO)(C22H21N3O)(CH3OH)](C24H20B)·CH3OH or [Mn(DQEA)(OAc)(CH3OH)]BPh4·CH3OH or [2]BPh4·CH3OH, by single-crystal X-ray diffraction reveal distinct differences in the geometry of coordination of the tripodal DQEA and DQMEA ligands to MnII ions. In the asymmetric unit, compound [1](BPh4)2·(CH2Cl2)1.45 crystallizes as a dimer in which each manganese(II) center is coordinated by the central amine nitrogen, the nitrogen atom of each quinoline group, and the methoxy-oxygen of the tetradentate DQMEA ligand, and two bridging-acetate oxygen atoms. The symmetric MnII centers have a distorted, octahedral geometry in which the quinoline nitrogen atoms are trans to each other resulting in co-planarity of the quinoline rings. For each MnII center, a coordinated acetate oxygen participates in C—H...O hydrogen-bonding interactions with the two quinolyl moieties, further stabilizing the trans structure. Within the crystal, weak π–π stacking interactions and intermolecular cation–anion interactions stabilize the crystal packing. In the asymmetric unit, compound [2]BPh4·CH3OH crystallizes as a monomer in which the manganese(II) ion is coordinated to the central nitrogen, the nitrogen atom of each quinoline group, and the alcohol oxygen of the tetradentate DQEA ligand, an oxygen atom of OAc, and the oxygen atom of a methanol ligand. The geometry of the MnII center in [2]BPh4·CH3OH is also a distorted octahedron, but the quinoline nitrogen atoms are cis to each other in this structure. Hydrogen bonding between the acetate oxygen atoms and hydroxyl (O—H...O) and quinolyl (C—H...O and N—H...O) moieties of the DQEA ligand stabilize the complex in this cis configuration. Within the crystal, dimerization of complexes occurs by the formation of a pair of intermolecular O3—H3...O2 hydrogen bonds between the coordinated hydroxyl oxygen of the DQEA ligand of one complex and an acetate oxygen of another. Additional hydrogen-bonding and intermolecular cation–anion interactions contribute to the crystal packing.

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