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

1985 ◽  
Vol 63 (10) ◽  
pp. 2752-2756 ◽  
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.

Structure–activity studies of β-carbolines. 2. Crystal and molecular structures of N-ethyl-3-carbamoyl-β-carboline

1984 ◽  
Vol 62 (9) ◽  
pp. 1803-1806 ◽  
Author(s):  
Alastair K. S. Muir ◽  
Penelope W. Codding
Keyword(s):  
Molecular Conformation ◽  
Current Model ◽  
Benzodiazepine Receptor ◽  
Molecular Structures ◽  
Side Chain ◽  
Receptor Binding Site ◽  
Crystal And Molecular Structures ◽  
Structure Activity ◽  
Synthetic Ligand ◽  
Packing Arrangement

The crystal and molecular structures of N-ethyl-3-carbamoyl-β-carboline, C14H13N3O, a synthetic ligand of the benzodiazepine receptor are reported. The space group is C2/c with a = 16.220(4), b = 7.728(4), c = 19.623(6) Å, β = 104.16(1)°, Z = 8. The carboxyamide side chain assumes an extended conformation and is almost coplanar with the β-carboline skeleton. The observed molecular conformation is compared to the current model for the receptor binding site. Hydrogen bonding and aromatic ring stacking determine the molecular packing arrangement.

Untersuchungen an Stickstoff-Brom-Verbindungen, IV / Studies on Nitrogen-Bromine Compounds, IV

1977 ◽  
Vol 32 (12) ◽  
pp. 1416-1420 ◽  
Author(s):  
Omar Jabay ◽  
Hans Pritzkow ◽  
Jochen Jander
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Structure Analysis ◽  
Electron Acceptors ◽  
Molecular Structures ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Solid Nitrogen ◽  
Intermolecular Contacts

The crystal and molecular structures of N-bromobenzamide (NBB), N-bromosuccinimide (NBS), and N,N-dibromobenzenesulfonamide (NBBS) were determined by X-ray structure analysis. The nitrogen atoms in NBB and NBS have a trigonal planar coordination (sp2) and the N—Br distances lie in the same range (1.82 A, 1.84 A). The N—Br distance in NBBS, where the nitrogen atom is sp3-hybridized, is somewhat longer (1.88 A). In these structures the molecules are connected by O···H—N (NBB), O···Br—N (NBS) or N···Br—N (NBBS) intermolecular bonds forming endless chains; positivated hydrogen atoms or, in case that they are absent, positivated bromine atoms act as electron acceptors with oxygen or sp3- hybridized nitrogen atoms. These results suggest, that in solid nitrogen tribromide, the crystal structure of which cannot be determined, the nitrogen atoms will be sp3-hybridized and intermolecular contacts via N—Br···N will occur.

Crystal and molecular structures of Si -(iodomethyl)silatranes with methyl substituents in β-position relative to the nitrogen atom

2018 ◽  
Vol 28 (3) ◽  
pp. 278-280 ◽  
Author(s):  
Vladimir I. Smirnov ◽  
Eleonora A. Zelbst ◽  
Galina A. Kuznetzova ◽  
Irina V. Sterkhova
Keyword(s):  
Nitrogen Atom ◽  
Molecular Structures ◽  
Crystal And Molecular Structures

N10-(2′-Mercaptoethanoyl)-2,2,5,5-tetramethyl-3,4-diathia-7,10-diaza-bicyclo[5.3.0]decane and its reaction with oxotrichlorobis(triphenylphosphine)rhenium(V)

1996 ◽  
Vol 74 (4) ◽  
pp. 574-582 ◽  
Author(s):  
H. Alarabi ◽  
R.A. Bell ◽  
H.E. Howard-Lock ◽  
J. Kowanetz ◽  
C.J.L. Lock
Keyword(s):  
Nitrogen Atom ◽  
Heavy Atom ◽  
Direct Methods ◽  
Ligand Molecule ◽  
Amine Nitrogen Atom ◽  
Rhenium Atom ◽  
Amine Nitrogen ◽  
Bond Lengths ◽  
X Ray Crystallography ◽  
Equivalent Distance

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.

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

2004 ◽  
Vol 74 (11) ◽  
pp. 1728-1733 ◽  
Author(s):  
Yu. A. Mednykh ◽  
Yu. A. Manaev ◽  
V. V. Volchkov ◽  
B. M. Uzhinov
Keyword(s):  
Nitrogen Atom ◽  
Amine Nitrogen Atom ◽  
Amine Nitrogen

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

2012 ◽  
Vol 10 (1) ◽  
pp. 146-156 ◽  
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

Crystal and molecular structures of two aryldiazenato complexes of molybdenum of the type [Mo(N2Ar)(S2CNMe2)3]

1980 ◽  
Vol 33 (4) ◽  
pp. 717 ◽  
Author(s):  
GA Williams ◽  
ARP Smith
Keyword(s):  
Nitrogen Atom ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Magnetic Moments ◽  
Nitro Derivative ◽  
Molecular Structures ◽  
Electron Donors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal and molecular structures of the aryldiazenato complexes of molybdenum, [Mo(N2C6H5)(S2CNMe2)3],CH2Cl2 (1), and the m-nitro derivative [Mo{N2C6H4(m-NO2)}-(S2CNMe2)3]2,�CH2Cl2,�H2O (2), have been determined by single-crystal X-ray diffraction methods at 294 K. Crystals of (1) are monoclinic, P21/n, a 13.056(1), b 13.366(1), c 15.350(1) Ǻ, β 93.80(1)°, Z 4. Crystals of (2) are monoclinic, C2/c, a 32.442(8), b 17.670(4), c 17.867(3) Ǻ, β 99.03(1)°, Z 8. Automatic diffractometry has provided significant Bragg intensities for 2849 (1) and 3898 (2) independent reflections and the structures have been refined by least-squares methods to R 0.036 (1) and 0.053 (2). The two unique molybdenum complexes in (2) are essentially chemically equivalent. The complexes in (1) and (2) possess the expected seven-coordinate pentagonal bipyramidal structures with the aryldiazenato ligands, singly bent, occupying axial positions. The N=N-Mo units are linear, and the bonding can be represented by N=N→Mo with the aryldiazenato ligands three-electron donors. The m-nitro substituent in (2) interacts with a dithiocarbamate (dtc) nitrogen atom, thereby affecting the redox behaviour of this compound. The possible significance of this O(nitro)...N(dtc) interaction to the mechanism, whereby included nitrobenzene solvent in the crystal lattice lowers the magnetic moments of ferric dithiocarbamates, is discussed.

Structure-activity studies of β-carbolines. 4. Crystal and molecular structures of t-butyl β-carboline-3-carboxylate and 2-(methoxycarbonyl)canthine-6-one

1988 ◽  
Vol 66 (12) ◽  
pp. 2981-2988 ◽  
Author(s):  
Penelope W. Codding ◽  
Maria B. Szkaradzinska ◽  
Aleksander W. Roszak ◽  
Lorraine J. Aha ◽  
Timothy J. Hagen ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Side Chain ◽  
Stacking Interactions ◽  
Lower Affinity ◽  
Space Group ◽  
High Affinity ◽  
Crystal And Molecular Structures ◽  
Structure Activity ◽  
The Difference

The crystal and molecular structures of two ligands for the benzodiazepine (BZ) receptor, t-butyl β-carboline-3-carboxylate, I (C16H16N2O2), and 2-(methoxycarbonyl)canthin-6-one, II (C16H10N2O3), are reported. The t-butyl β-carboline compound has high affinity for the receptor and is an antagonist; in contrast, the canthin-6-one has a 10-fold lower affinity for the receptor and no determinable in vivo activity. The space group for I is P21/c with a = 11.756(1), b = 11.2324(8), c = 11.964(1) Å, and β = 105.99(1)°. For II, the space group is also P21/c with a = 9.317(1), b = 7.964(1), c = 17.180(3) Å, and β = 104.173(7)°. The orientation of the alkyl-carboxylate side chain is different in the two molecules and may be related to the difference in affinity and in vivo activity of the ligands. In addition, the packing arrangements in the two structures are dominated by π-stacking interactions; and, in the case of the t-butyl compound, by hydrogen bonding.

Crystal and Molecular Structures of the Sulfurization and Selenation Products of Bis[bis(trimethylsilyl)amino]germanium(II). Crystal Structure of (Triphenylphosphine)gold(I) Bis(trimethylsilyl)amide

2000 ◽  
Vol 55 (5) ◽  
pp. 347-351 ◽  
Author(s):  
Gerald L. Wegner ◽  
Alexander Jockisch ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Elemental Sulfur ◽  
Crystal Structure Analysis ◽  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Planar Configuration ◽  
High Yields ◽  
Single Crystal Structure Analysis

Treatment of bis[bis(trimethylsilyl)amino]germanium(II) with elemental sulfur or selenium affords high yields of the corresponding monosulfide [(Me3Si)2N]2GeS and selenide [(Me3Si)2N]2GeSe, respectively. The crystalline products have now been shown to be cyclic dimers with (GeS/Se)2 four-membered rings by X-ray single crystal structure analysis. The crystal structure of (triphenylphosphine)gold(I) bis(trimethylsilyl)amide (Ph3P)Au-N(SiMe3)2 has also been determined. The molecule is a monomer with a tricoordinate nitrogen atom in a planar configuration [Si2NAu]. The compound does not undergo insertion of the bis[bis(trimethylsilyl)amino]germylene.

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