Synthesis, Characterization and Structure of Tribromo(2-phenyl- 1,8-naphthyridine)gold(III)

2011 ◽  
Vol 66 (7) ◽  
pp. 677-680
Author(s):  
Ricardo Schmidt ◽  
Sergio A. Moya ◽  
Pedro Aguirre ◽  
Mauricio Fuentealba ◽  
Markus Leboschka ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Dihedral Angle ◽  
1H Nmr Spectroscopy ◽  
Pyridine Ring ◽  
Weak Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Van Der Waals Radii

Neutral tribromo(2-phenyl-1,8-naphthyridine)gold(III), AuBr3(N-N), has been prepared by reaction of KAuBr4 with the ligand in CHCl3/C2H5OH and was characterized by 1H NMR spectroscopy and X-ray diffraction. The molecular and crystal structure of AuBr3(N-N) · 0.5 THF (triclinic, P1̄, a = 11.314(2), b = 12.350(3), c = 14.628(3) A° , α = 107.96(3), β = 98.86(3), γ = 107.29(3)◦, Z = 4, 173 K) shows coordination of the N8 nitrogen atom situated in the unsubstituted pyridine ring to the planar four-coordinate AuIII center. Whereas the AuBr3N best planes and the coordinated naphthyridine rings are not far from orthogonal (ω ~ 105◦), the phenyl substituents were found in the crystal with a ca. 22◦ dihedral angle relative to the naphthyridine plane. Intermolecular Au· · ·Br distances close to the sum of the van der Waals radii indicate very weak interactions to form a quasi-dimeric arrangement in the crystal.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

scholarly journals Synthesis, Structure, and Properties of a Dinuclear Cu(II) Coordination Polymer Based on Quinoxaline and 3,3-Thiodipropionic Acid Ligands

2021 ◽  
Author(s):  
Adedibu Clement Tella ◽  
Samson Owalude ◽  
Vincent Adimula ◽  
Adetola Oladipo ◽  
Victoria Olayemi ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Coordination Polymer ◽  
Elemental Analysis ◽  
Catalytic Reduction ◽  
Copper Acetate ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.

scholarly journals Reactions of Dihaloboranes with Electron-Rich 1,4-Bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadienes

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2875
Author(s):  
Li Ma ◽  
Xiaolin Zhang ◽  
Wenbo Ming ◽  
Shengxin Su ◽  
Xiaoyong Chang ◽  
...  
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
1H Nmr Spectroscopy ◽  
Variable Temperature ◽  
Organosilicon Compounds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy ◽  
Bond Character

The reactions of electron-rich organosilicon compounds 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (1), 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (2), and 1,1′-bis(trimethylsilyl)-1,1′-dihydro-4,4′-bipyridine (12) with B-amino and B-aryl dihaloboranes afforded a series of novel B=N-bond-containing compounds 3–11 and 13. The B=N rotational barriers of 7 (>71.56 kJ/mol), 10 (58.79 kJ/mol), and 13 (58.65 kJ/mol) were determined by variable-temperature 1H-NMR spectroscopy, thus reflecting different degrees of B=N double bond character in the corresponding compounds. In addition, ring external olefin isomers 11 were obtained by a reaction between 2 and DurBBr2. All obtained B=N-containing products were characterized by multinuclear NMR spectroscopy. Compounds 5, 9, 10a, 11, and 13a were also characterized by single-crystal X-ray diffraction analysis.

Somersetite, Pb8O(OH)4(CO3)5, a new complex hydrocerussite-related mineral from the Mendip Hills, England

2018 ◽  
Vol 82 (5) ◽  
pp. 1211-1224 ◽  
Author(s):  
Oleg I. Siidra ◽  
Diana O. Nekrasova ◽  
Rick Turner ◽  
Anatoly N. Zaitsev ◽  
Nikita V. Chukanov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Infrared Spectrum ◽  
Weak Interactions ◽  
New Mineral ◽  
Single Crystal Xrd ◽  
X Ray Diffraction ◽  
Electron Pairs ◽  
Xrd Pattern ◽  
X Ray ◽  
Simplified Formula

ABSTRACTThe new mineral somersetite, has been found at Torr Works (‘Merehead quarry’) in Somerset, England, United Kingdom. Somersetite is green or white (typically it is similar visually to hydrocerussite-like minerals but with a mint-green tint), forms plates and subhedral grains up to 5 mm across and up to 2 mm thick. In bi-coloured crystals it forms very thin intergrowths with plumbonacrite. The empirical formula of somersetite is Pb8.00C5.00H4.00O20. The simplified formula is Pb8O(OH)4(CO3)5, which requires: PbO = 87.46, CO2 = 10.78, H2O = 1.76, total 100.00 wt.%.The infrared spectrum of somersetite is similar to that of plumbonacrite and, to a lesser degree, hydrocerussite. Somersetite is hexagonal, P63/mmc, a = 5.2427(7), c = 40.624(6) Å, V = 967.0(3) Å3 and Z = 2. The eight strongest reflections of the powder X-ray diffraction (XRD) pattern [d,Å(I)(hkl)] are: 4.308(33)(103), 4.148(25)(104), 3.581(40)(107), 3.390(100)(108), 3.206(55)(109), 2.625(78)(110), 2.544(98)(0.0.16) and 2.119(27)(1.0.17). The crystal structure was solved from single-crystal XRD data giving R1 = 0.031. The structure of somersetite is unique and consists of the alternation of the electroneutral plumbonacrite-type [Pb5O(OH)2(CO3)3]0 and hydrocerussite-type [Pb3(OH)2(CO3)2]0 blocks separated by stereochemically active lone electron pairs on Pb2+. There are two blocks of each type per unit cell in the structure, which corresponds to the formula [Pb5O(OH)2(CO3)3][Pb3(OH)2(CO3)2] or Pb8O(OH)4(CO3)5 in a simplified representation. The 2D blocks are held together by weak Pb–O bonds and weak interactions between lone pairs.

Synthesis and Characterization of Three Novel Nitrogen-containing Macrolides

2011 ◽  
Vol 66 (9) ◽  
pp. 930-934
Author(s):  
Xin Leng ◽  
Bingqin Yang ◽  
Yuanyuan Liu ◽  
Yi Xie ◽  
Jie Tong
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
1H Nmr Spectroscopy ◽  
Mass Spectra ◽  
Synthesis And Characterization ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
X Ray

Three novel nitrogen-containing macrolides have been synthesized by esterification. All of them have been characterized by infrared (IR), elemental analysis, mass spectra (MS), and 1H NMR spectroscopy, and their crystal structures were determined by single-crystal X-ray diffraction. The preparation methods and the intermolecular associations based on C-H・・・O hydrogen bonds and π- π stacking interactions are discussed.

Influence of fluorine side-group substitution on the crystal structure formation of benzene-1,3,5-trisamides

CrystEngComm ◽  
2014 ◽  
Vol 16 (39) ◽  
pp. 9273-9283 ◽  
Author(s):  
Christoph Zehe ◽  
Marko Schmidt ◽  
Renée Siegel ◽  
Klaus Kreger ◽  
Venita Daebel ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Formation ◽  
Solid State Nmr ◽  
Quantum Chemical ◽  
Side Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Structure Formation

The crystal structure of 1,3,5-tris(2-fluoro-2-methylpropionylamino)benzene was solved by combining powder X-ray diffraction, solid-state NMR spectroscopy and quantum chemical calculations.

scholarly journals Crystal structure determination of karibibite, an Fe3+ arsenite, using electron diffraction tomography

2017 ◽  
Vol 81 (5) ◽  
pp. 1191-1202 ◽  
Author(s):  
Fernando Colombo ◽  
Enrico Mugnaioli ◽  
Oriol Vallcorba ◽  
Alberto García ◽  
Alejandro R. Goñi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Dft Calculations ◽  
Density Functional ◽  
Weak Interactions ◽  
Diffraction Tomography ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Parameters

AbstractThe crystal structure of karibibite, Fe33+(As3+O2)4(As23+O5)(OH), from the Urucum mine (Minas Gerais, Brazil), was solved and refined from electron diffraction tomography data [R1 = 18.8% for F > 4σ(F)] and further confirmed by synchrotron X-ray diffraction and density functional theory (DFT) calculations. The mineral is orthorhombic, space group Pnma and unit-cell parameters (synchrotron X-ray diffraction) are a = 7.2558(3), b = 27.992(1), c = 6.5243 (3) Å, V = 1325.10(8) Å3, Z = 4. The crystal structure of karibibbite consists of bands of Fe3+O6 octahedra running along a framed by two chains of AsO3 trigonal pyramids at each side, and along c by As2O5 dimers above and below. Each band is composed of ribbons of three edge-sharing Fe3+O6 octahedra, apex-connected with other ribbons in order to form a kinked band running along a. The atoms As(2) and As(3), each showing trigonal pyramidal coordination by O, share the O(4) atom to form a dimer. In turn, dimers are connected by the O(3) atoms, defining a zig-zag chain of overall (As3+O2)n-n stoichiometry. Each ribbon of (Fe3+O6) octahedra is flanked on both edges by the (As3+O2)n-n chains. The simultaneous presence of arsenite chains and dimers is previously unknown in compounds with As3+. The lone-electron pairs (4s2) of the As(2) and As(3) atoms project into the interlayer located at y = 0 and y = ½, yielding probable weak interactions with the O atoms of the facing (AsO2) chain.The DFT calculations show that the Fe atoms have maximum spin polarization, consistent with the Fe3+ state.

scholarly journals Crystal structure of 5-[(benzoyloxy)methyl]-5,6-dihydroxy-4-oxocyclohex-2-en-1-yl benzoate

2020 ◽  
Vol 76 (7) ◽  
pp. 1096-1100
Author(s):  
Theerachart Leepasert ◽  
Patchreenart Saparpakorn ◽  
Kittipong Chainok ◽  
Tanwawan Duangthongyou
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Natural Product ◽  
Dihedral Angle ◽  
Absolute Configuration ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ring Form

The crystal structure of the natural product zeylenone, C21H18O7, was confirmed by single-crystal X-ray diffraction. The crystal structure has three chiral centers at positions C1, C5 and C6 of the cyclohexanone ring, but the absolute configuration could not be determined reliably. The methyl benzoate and benzoyloxy substituents at positions C1 and C5 of the cyclohexenone ring are on the same side of the ring with the dihedral angle between their mean planes being 16.25 (10)°. These rings are almost perpendicular to the cyclohexenone ring. The benzoate groups and two hydroxyl groups on the cyclohexenone ring form strong hydrogen bonds to consolidate the crystal structure. In addition, weak C—H...O hydrogen bonds also contribute to the packing of the structure.

Synthesis, structure and biological activity of four new picolinohydrazonamide derivatives

2020 ◽  
Vol 76 (7) ◽  
pp. 673-680
Author(s):  
Małgorzata Szczesio ◽  
Katarzyna Gobis ◽  
Izabela Korona-Głowniak ◽  
Ida Mazerant-Politowicz ◽  
Dagmara Ziembicka ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Nmr Spectroscopy ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
Essential Role ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zwitterionic Form ◽  
Solvent Molecules

Four new picolinohydrazonamide derivatives, namely, 6-methyl-N′-(morpholine-4-carbonothioyl)picolinohydrazonamide, C12H17N5OS, 6-chloro-N′-(morpholine-4-carbonothioyl)picolinohydrazonamide methanol monosolvate, C11H14ClN5OS·CH3OH, 6-chloro-N′-(4-phenylpiperazine-1-carbonothioyl)picolinohydrazonamide, C17H19ClN6S, and 6-chloropicolinohydrazonamide, C6H7ClN4, have been synthesized and characterized by NMR spectroscopy and single-crystal low-temperature X-ray diffraction. In addition, their antibacterial and anti-yeast activities have been determined. The first three compounds adopt the zwitterionic form in the crystal structure regardless of the presence or absence of solvent molecules in the structure. They also adopt the same symmetry, i.e. P21/c (P21/n), unlike the fourth structure which is chiral and has the space group P212121. For all the studied cases, intermolecular N—H...O and N—H...N hydrogen bonds play an essential role in the formation of the structures.

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