Cobalt(II) chloride complexes with some phosphine oxides: compatibility between structural data for the solid complexes and their stability constants in acetone medium

Binary complexes of general formula CoCl2L2, where L = triphenylphosphine oxide (TPPO), benzyldiphenylphosphine oxide (BDPPO), dibenzylphenylphosphine oxide (DBPPO) and tribenzylphosphine oxide (TBPO) were considered concerning X-ray structural data for the complexes in the solid state and their stability constants in acetone solution. Compatibility between structural data and stability constants are pointed out. Previous investigations showed that in acetone medium, with CoCl2 as reference acceptor, the following basicity order is obeyed: TBPO > DBPPO > BDPPO > TPPO. This sequence is supported by X-ray diffraction data of the solid complexes and by electrolytic conductance values for these complexes both in acetone and in nitromethane media.

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Tubulin structure at intermediate resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140634 ◽

1995 ◽

Vol 53 ◽

pp. 852-853

Author(s):

K. H. Downing ◽

S. G. Wolf ◽

E. Nogales

Keyword(s):

High Resolution ◽

Structural Data ◽

Therapeutic Drug ◽

Zinc Ions ◽

Two Dimensional ◽

X Ray Diffraction ◽

X Ray ◽

Negative Stain ◽

Functional Mechanisms ◽

Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

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Xenon Trioxide Adducts of O-Donor Ligands; [(CH3)2CO]3XeO3, [(CH3)2SO]3(XeO3)2, (C5H5NO)3(XeO3)2, and [(C6H5)3PO]2XeO3

10.26434/chemrxiv.7092263.v1 ◽

2018 ◽

Author(s):

Katherine Marczenko ◽

James Goettel ◽

Gary Schrobilgen

Keyword(s):

Room Temperature ◽

Triphenylphosphine Oxide ◽

Donor Ligands ◽

Mechanical Shock ◽

X Ray Diffraction ◽

X Ray ◽

Oxygen Coordination ◽

Xenon Trioxide ◽

Distorted Octahedra ◽

Coordination Spheres

Oxygen coordination to the Xe(VI) atom of XeO3 was observed in its adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine-N-oxide, and acetone. The crystalline adducts were characterized by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Unlike solid XeO3, which detonates when mechanically or thermally shocked, the solid [(C6H5)3PO]2XeO3, [(CH3)2SO]3(XeO3)2, and (C5H5NO)3(XeO3)2 adducts are insensitive to mechanical shock, but undergo rapid deflagration when ignited by a flame. Both [(C6H5)3PO]2XeO3 and (C5H5NO)3(XeO3)2 are air-stable whereas [(CH3)2SO]3(XeO3)2 slowly decomposes over several days and [(CH3)2CO]3XeO3 undergoes adduct dissociation at room temperature. The xenon coordination sphere of [(C6H5)3PO]2XeO3 is a distorted square pyramid which provides the first example of a five-coordinate XeO3 adduct. The xenon coordination spheres of the remaining adducts are distorted octahedra comprised of three Xe---O secondary contacts that are approximately trans to the primary Xe–O bonds of XeO3. Quantum-chemical calculations were used to assess the Xe---O adduct bonds, which are predominantly electrostatic σ-hole bonds between the nucleophilic oxygen atoms of the bases and the σ-holes of the xenon atoms.

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Compressibility of β-As4S4: an in situ high-pressure single-crystal X-ray study

Mineralogical Magazine ◽

10.1180/minmag.2012.076.4.12 ◽

2012 ◽

Vol 76 (4) ◽

pp. 963-973 ◽

Cited By ~ 6

Author(s):

G. O. Lepore ◽

T. Boffa Ballaran ◽

F. Nestola ◽

L. Bindi ◽

D. Pasqual ◽

...

Keyword(s):

Pressure Range ◽

Substantial Reduction ◽

Structural Data ◽

Unit Cell ◽

Van Der Waals Interactions ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

X Ray ◽

Cell Parameters ◽

Intermolecular Distances

AbstractAmbient temperature X-ray diffraction data were collected at different pressures from two crystals of β-As4S4, which were made by heating realgar under vacuum at 295ºC for 24 h. These data were used to calculate the unit-cell parameters at pressures up to 6.86 GPa. Above 2.86 GPa, it was only possible to make an approximate measurement of the unit-cell parameters. As expected for a crystal structure that contains molecular units held together by weak van der Waals interactions, β-As4S4 has an exceptionally high compressibility. The compressibility data were fitted to a third-order Birch–Murnaghan equation of state with a resulting volume V0 = 808.2(2) Å3, bulk modulus K0 = 10.9(2) GPa and K' = 8.9(3). These values are extremely close to those reported for the low-temperature polymorph of As4S4, realgar, which contains the same As4S4 cage-molecule. Structural analysis showed that the unit-cell contraction is due mainly to the reduction in intermolecular distances, which causes a substantial reduction in the unit-cell volume (∼21% at 6.86 GPa). The cage-like As4S4 molecules are only slightly affected. No phase transitions occur in the pressure range investigated.Micro-Raman spectra, collected across the entire pressure range, show that the peaks associated with As–As stretching have the greatest pressure dependence; the S–As–S bending frequency and the As–S stretching have a much weaker dependence or no variation at all as the pressure increases; this is in excellent agreement with the structural data.

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Purification, crystallization and preliminary X-ray diffraction analysis of a hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase (HCT) fromCoffea canephorainvolved in chlorogenic acid biosynthesis

Acta Crystallographica Section F Structural Biology and Crystallization Communications ◽

10.1107/s1744309112019082 ◽

2012 ◽

Vol 68 (7) ◽

pp. 824-828 ◽

Cited By ~ 3

Author(s):

Laura A. Lallemand ◽

James G. McCarthy ◽

Sean McSweeney ◽

Andrew A. McCarthy

Keyword(s):

Structural Data ◽

Coffea Canephora ◽

Molecular Replacement ◽

X Ray Diffraction ◽

X Ray ◽

Cell Parameters ◽

Key Enzyme ◽

Substrate Specifities ◽

Drop Technique ◽

Better Than

Chlorogenic acids (CGAs) are a group of soluble phenolic compounds that are produced by a variety of plants, includingCoffea canephora(robusta coffee). The last step in CGA biosynthesis is generally catalysed by a specific hydroxycinnamoyl-CoA quinate hydroxycinnamoyltransferase (HQT), but it can also be catalysed by the more widely distributed hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase (HCT). Here, the cloning and overexpression of HCT fromC. canephorainEscherichia colias well as its purification and crystallization are presented. Crystals were obtained by the sitting-drop technique at 293 K and X-ray diffraction data were collected on the microfocus beamline ID23-2 at the ESRF. The HCT crystals diffracted to better than 3.0 Å resolution, belonged to space groupP42212 with unit-cell parametersa=b= 116.1,c= 158.9 Å and contained two molecules in the asymmetric unit. The structure was solved by molecular replacement and is currently under refinement. Such structural data are needed to decipher the molecular basis of the substrate specifities of this key enzyme, which belongs to the large plant acyl-CoA-dependent BAHD acyltransferase superfamily.

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Functionalized triphenylphosphine oxide-based manganese(II) complexes for luminescent printing

Dalton Transactions ◽

10.1039/d1dt00914a ◽

2021 ◽

Author(s):

Xiaomeng Huang ◽

Yanyan Qin ◽

Pengfei She ◽

Haixing Meng ◽

Shu-Juan Liu ◽

...

Keyword(s):

Single Crystal ◽

Diffraction Analysis ◽

Triphenylphosphine Oxide ◽

X Ray Diffraction ◽

X Ray

Three novel neutral manganese(II) complexes (TPhPONMe2)2MnBr2, (TPhPOOMe)2MnBr2, and (TPhPOCF3)2MnBr2 have been designed and synthesized based on functionalized Ph3PO ligand. These structures are clarified by single crystal X-ray diffraction analysis, which...

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Sergevanite, Na15(Ca3Mn3)(Na2Fe)Zr3Si26O72(OH)3·H2O, a new eudialyte-group mineral from the Lovozero alkaline massif, Kola Peninsula

The Canadian Mineralogist ◽

10.3749/canmin.2000006 ◽

2020 ◽

Vol 58 (4) ◽

pp. 421-436 ◽

Cited By ~ 3

Author(s):

Nikita V. Chukanov ◽

Sergey M. Aksenov ◽

Igor V. Pekov ◽

Dmitriy I. Belakovskiy ◽

Svetlana A. Vozchikova ◽

...

Keyword(s):

Kola Peninsula ◽

Structural Data ◽

New Mineral ◽

X Ray Diffraction ◽

Calculated Density ◽

Eudialyte Group ◽

Group Mineral ◽

X Ray ◽

Mohs Hardness ◽

Alkaline Massif

ABSTRACT The new eudialyte-group mineral sergevanite, ideally Na15(Ca3Mn3)(Na2Fe)Zr3Si26O72(OH)3·H2O, was discovered in highly agpaitic foyaite from the Karnasurt Mountain, Lovozero alkaline massif, Kola Peninsula, Russia. The associated minerals are microcline, albite, nepheline, arfvedsonite, aegirine, lamprophyllite, fluorapatite, steenstrupine-(Ce), ilmenite, and sphalerite. Sergevanite forms yellow to orange-yellow anhedral grains up to 1.5 mm across and the outer zones of some grains of associated eudialyte. Its luster is vitreous, and the streak is white. No cleavage is observed. The Mohs' hardness is 5. Density measured by equilibration in heavy liquids is 2.90(1) g/cm3. Calculated density is equal to 2.906 g/cm3. Sergevanite is nonpleochroic, optically uniaxial, positive, with ω = 1.604(2) and ε = 1.607(2) (λ = 589 nm). The infrared spectrum is given. The chemical composition of sergevanite is (wt.%; electron microprobe, H2O determined by HCN analysis): Na2O 13.69, K2O 1.40, CaO 7.66, La2O3 0.90, Ce2O3 1.41, Pr2O3 0.33, Nd2O3 0.64, Sm2O3 0.14, MnO 4.15, FeO 1.34, TiO2 1.19, ZrO2 10.67, HfO2 0.29, Nb2O5 1.63, SiO2 49.61, SO3 0.77, Cl 0.23, H2O 4.22, –O=Cl –0.05, total 100.22. The empirical formula (based on 25.5 Si atoms pfu, in accordance with structural data) is H14.46Na13.64K0.92Ca4.22Ce0.27La0.17Nd0.12Pr0.06Sm0.02Mn1.81Fe2+0.58Ti0.46Zr2.67Hf0.04Nb0.38Si25.5S0.30Cl0.20O81.35. The crystal structure was determined using single-crystal X-ray diffraction data. The new mineral is trigonal, space group R3, with a = 14.2179(1) Å, c = 30.3492(3) Å, V = 5313.11(7) Å3, and Z = 3. In the structure of sergevanite, Ca and Mn are ordered in the six-membered ring of octahedra (at the sites M11 and M12), and Na dominates over Fe2+ at the M2 site. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 7.12 (70) (110), 5.711 (43) (202), 4.321 (72) (205), 3.806 (39) (033), 3.551 (39) (220, 027), 3.398 (39) (313), 2.978 (95) (), 2.855 (100) (404). Sergevanite is named after the Sergevan' River, which is near the discovery locality.

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Synthesis, Crystal Structure, Thermal Analysis, and DFT Calculations of Molecular Copper(II) Chloride Complexes with Bitopic Ligand 1,1,2,2-tetrakis(pyrazol-1-yl)ethane

Crystals ◽

10.3390/cryst9040222 ◽

2019 ◽

Vol 9 (4) ◽

pp. 222

Author(s):

Lider ◽

Sukhikh ◽

Smolentsev ◽

Semitut ◽

Filatov ◽

...

Keyword(s):

Dft Calculations ◽

Coordination Compounds ◽

Density Functional ◽

Water Molecules ◽

X Ray Diffraction ◽

Chloride Complexes ◽

Functional Theory ◽

X Ray ◽

Lattice Water ◽

Ir Bands

Two binuclear coordination compounds of Cu(II) chloride with the bitopic ligand 1,1,2,2-tetrakis(pyrazol-1-yl)ethane (Pz4) of the composition [Cu2(µ2Pz4)(DMSO)2Cl4]·4H2O and [Cu2(µ2Pz4)(DMSO)2Cl4]∙2DMSO were prepared and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder diffraction analysis. It was shown that in contrast to silver(I) and copper(II) nitrates, copper(II) chloride forms discrete complexes instead of coordination polymers. The supramolecular structure of the complex [Cu2(µ2Pz4)(DMSO)2Cl4]·4H2O with lattice water molecules is formed by OH···Cl and OH···O hydrogen bonds. Density functional theory (DFT) calculations of vibrational frequencies of the ligand and its copper(II) complex allowed for assigning IR bands to specific vibrations.

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Structural Systematics of Metal Acetylide Complexes: X-Ray Studies of Some 'Extended-Chain' Gold σ-Acetylide Complexes

Australian Journal of Chemistry ◽

10.1071/c97049 ◽

1997 ◽

Vol 50 (10) ◽

pp. 991 ◽

Cited By ~ 14

Author(s):

Ian R. Whittall ◽

Mark G. Humphrey ◽

David C. R. Hockless

Keyword(s):

Ground State ◽

Structural Data ◽

Monoclinic Space Group ◽

Confidence Limits ◽

X Ray Diffraction ◽

Triclinic Space Group ◽

Space Group ◽

X Ray ◽

Back Bonding ◽

Ground State Geometry

The structures of Au(4-C≡CC6H4XYC6H4-4′-NO2)(PPh3) (XY = (E )-CH=CH (1), (Z)-CH=CH (2), C≡C (3), N=CH (4)) have been determined by single-crystal X-ray diffraction analyses, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a8·847(1), b 17·870(4), c 19·705(3) Å, α116·25(1), β 93·33(1), γ 92·64(2)˚, Z 4, 6747 unique reflections (703 parameters), converging at R 0·025 and Rw 0·029. For (2), crystals are monoclinic, space group P 21/a, with a 10·718(6), b 19·398(5), c14·469(3) Å, β 108·96(2)˚, Z 4, 3295 unique reflections (352 parameters), converging atR 0·040 and Rw 0·034. For (3), crystals are triclinic, space group P-1, with a 10·671(4), b 17·599(7), c 18·220(8) Å, α 116·31(3), β 105·00(4), γ 95·08(4)˚, Z 4, 4828 unique reflections (703 parameters), converging at R 0·043 and Rw 0·030. For (4), crystals are triclinic, space group P-1, with a 8·8314(6), b 17·834(2), c 20·001(2) Å, α 115·249(7), β 90·930(7), γ 94·082(7)˚, Z 4, 4724 unique reflections (703 parameters), converging at R 0·035 and Rw 0·034. Despite the [ligated metal donor]-bridge-[nitro acceptor] composition of these complexes, Au–C and C≡C distances are normal and consistent with minimal allenylidene contribution to the ground-state geometry. Within the 3σ confidence limits, the structural data do not provide evidence for π*-back-bonding in these complexes

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Synthesis and Electrochemistry of Aluminum Porphycenes: Crystal and Molecular Structure of Methyl-σ-Bonded Aluminum Etioporphycene

Journal of Porphyrins and Phthalocyanines ◽

10.1002/(sici)1099-1409(199704)1:2<109::aid-jpp13>3.0.co;2-4 ◽

1997 ◽

Vol 01 (02) ◽

pp. 109-119 ◽

Cited By ~ 3

Author(s):

ROGER GUILARD ◽

VIRGINIE PICHON-PESME ◽

HASSANE LACHEKAR ◽

CLAUDE LECOMTE ◽

ALLY M. AUKAULOO ◽

...

Keyword(s):

Molecular Structure ◽

Crystal And Molecular Structure ◽

Structural Data ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

H Nmr ◽

Axial Ligands ◽

Uv Visible

The synthesis and characterization of three monomeric aluminum porphycenes with anionic or σ-bonded axial ligands is reported. The investigated compounds are represented as ( EtioPc ) Al ( CH 3) and ( EtioPc ) AlX where EtioPc represents the dianion of etioporphycene and X = Cl − or OH −. Each synthesized complex was characterized by mass spectrometry. 1 H NMR, IR and UV-visible spectroscopies as well as by electrochemistry. Comparisons are made between the properties of complexes in the aluminum etioporphycene series and related chloro- or methyl σ-bonded Al ( III ) porphyrins containing octaethylporphyrin ( OEP ) or tetraphenylporphyrin ( TPP ) macrocycles. Comparisons are also made between the currently investigated compounds and a previously reported Al ( III ) μ-oxo dimer, [( EtioPc ) Al ]2 O . In addition, the crystal and molecular structure of ( EtioPc ) Al ( CH 3) was determined by X-ray diffraction. The molecular structure of this methyl-σ-bonded aluminum etioporphycene provides the first structural data for an aluminum porphycene compound. The aluminum(III) atom in ( EtioPc ) Al ( CH 3) is pentacoordinated and is located 0.54 Å from the plane of the four N -nitrogens.

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Synthesis, Characterization, and Catalytic Activity of a Series of Aluminium–Amidate Complexes

Australian Journal of Chemistry ◽

10.1071/ch14514 ◽

2015 ◽

Vol 68 (3) ◽

pp. 357 ◽

Cited By ~ 6

Author(s):

Kevin P. Yeagle ◽

Darryl Hester ◽

Nicholas A. Piro ◽

William G. Dougherty ◽

W. Scott Kassel ◽

...

Keyword(s):

Catalytic Activity ◽

Nmr Spectroscopy ◽

Diffraction Analysis ◽

13C Nmr ◽

13C Nmr Spectroscopy ◽

X Ray Diffraction ◽

Metathesis Reaction ◽

Chloride Complexes ◽

1H And 13C Nmr ◽

X Ray

The aluminium complexes {[κ2-N,O-(t-BuNCOPh)]AlMe2}2 (2), [κ2-N,O-(t-BuNCOPh)]2AlMe (3), and [κ2-N,O-(t-BuNCOPh)]3Al (4) were prepared through the protonolysis reaction between trimethylaluminium and one, two, or three equivalents, respectively, of N-tert-butylbenzamide. Complex 2 was also prepared via a salt metathesis reaction between K(t-BuNCOPh) and dimethylaluminium chloride. Complexes 2–4 were characterized using 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction analysis of the complexes corroborated ligand : metal stoichiometries and revealed that all the amidate ligands coordinate to the aluminium ion in a κ2 fashion. The Al–amidate complexes 2–4 were viable catalyst precursors for the Meerwein–Ponndorf–Verley–Oppenauer reduction–oxidation manifold, successfully interconverting several classes of carbonyl and alcohol substrates.

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