Crystal Structure of mer-(PMe3)-trans(PEt3)(PPri3)H-trans-Cl2Ir III at 146 K

1997 ◽  
Vol 50 (1) ◽  
pp. 75 ◽  
Author(s):  
Evert J. Ditzel ◽  
K. David Griths ◽  
Glen B. Robertson
Keyword(s):  
Structure Refinement ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Torsion Angles ◽  
X Ray ◽  
Face To Face ◽  
Hydride Ligand ◽  
Phosphine Complex ◽  
Metal Ligand

The structure of the novel mixed-phosphine complex mer(PMe3)-trans(PEt3)(PPri3)H-trans-Cl2IrIII has been determined by single-crystal X-ray diffraction analysis at 146±3 K. Crystals are monoclinic, space group P 21/c, with a 7·414(4), b 15·073(3), c 9·796(2) Å, β 97·46(1) and Z 4. Structure refinement by constrained (2xC-C distances) full-matrix least-squares analysis (2378 unique reflections, 217 parameters) converged with R 0·049 and ωR 0·055. The PPri3 ligand is face-to-face configured with the unique Pri group eclipsing the hydride ligand. The PEt3 ligand is asymmetrically configured with Ir-P-C-C torsion angles 174, –72 and –146°. Metal{ligand distances are: Ir{P(1,2,3) 2·366(4), 2·372(4), 2·306(4) Å; Ir-Cl(1,2) 2·386(4), 2·372(4) Å. The P-Ir-P(trans) angle is 157·2(1)°.

Crystal-Structure of 0.53[Mer-(Pme2ph)3cl3iriii] 0.47[Mer-(Pme2ph)3- Trans-Cl2hiriii]

1988 ◽  
Vol 41 (5) ◽  
pp. 807 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Structure Refinement ◽  
Site Occupancy ◽  
Methanol Solution ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Weighted Averages ◽  
Ligand Structure ◽  
Metal Ligand

Evaporation of a methanol solution containing both mer -(PMe2Ph)3Cl3IrIII (1) and mer -(Pme2Ph)3H-trans-Cl2IrIII (2) yields a new crystalline species (3) which is morphologically distinct from either (1) or (2). The structure of (3) has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group P21/c, with a 15.747(2), b 10.305(1), c 16.790(2)Ǻ, β 92.75(3)� and Z 4, and contain, in approximately equal amounts, discrete molecules of both (1) and (2) distributed randomly in common lattice sites. Site content differs only according to whether there is H or Cl trans to the unique phosphine ligand . Structure refinement by full-matrix least-squares analysis (6183 reflections, 413 parameters) converged with R = 0.026, Rw = 0.034, and site occupancy factor for the unique chlorine atom equal to 0.530(4). Molecules each exhibit the conformation observed for pure (1) [pure (2) differs]. Derived metal- ligand distances are very similar to the weighted averages [53% (1), 47% (2)] of the corresponding distances in (1) and (2).

Crystal and Molecular Structure of mer-cis-(PEt2Ph)2(PPri3)H-trans-Cl2IrIII

1996 ◽  
Vol 49 (11) ◽  
pp. 1253 ◽  
Author(s):  
EJ Ditzel ◽  
KD Griffiths ◽  
GB Robertson
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Crystal And Molecular Structure ◽  
Structure Refinement ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Metal Ligand

The structure of mer-cis-(PEt2Ph)2(PPri3)H-trans-Cl2IrIII (4) has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group P21/c, with a 11.607(1), b 21.553(1), c 14.066(1) Ǻ, β 109.04(1)? and Z 4. Structure refinement by full-matrix least-squares analysis (3244 unique reflections, 316 parameters) converged with R 0.034 and Rw 0.041. The PEt2Ph ligands are similarly disposed to their PMe2Ph counterparts in mer-cis-(PEt2Ph)2(PPri3)H-trans-Cl2IrIII (2) but the PPri3 ligands are differently oriented and differently configured. Metal-ligand distances [ Ir -P(1,2,3) 2.333(2), 2.404(2), 2.368(2) Ǻ; Ir-Cl (1,2) 2.388(2), 2.400(2) Ǻ] are all within c. 0.02 Ǻ of those in (2). The P-Ir -P(trans) angle is 155.3(1)°.

Ten-Vertex Polyhedral Monocarbaborane Chemistry. The Novel High-Yield Formation of the Ten-Vertex closo Compound [6-(PMe2Ph)-closo-1-CB9H9] from the Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11]

1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
High Yield ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
X Ray ◽  
Yield Formation ◽  
Boiling Toluene

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.

The Crystal and Molecular Structures of Two Modifications of cis-Dichloro-mer-tris-(dimethylphenylphosphine)hydridoiridium(III)

1988 ◽  
Vol 41 (3) ◽  
pp. 283 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Heavy Atom ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Metal Ligand ◽  
Ligand Bond

The structures of two crystalline modifications of mer -(Pme2Ph)3H-cis-Cl2IrIII, (1), have been determined from single-crystal X-ray diffraction data. Modification (A) is monoclinic, space group P21/c with a 12.635(1), b 30.605(3), c 14.992(2)Ǻ, β 110.01(2)° and Z = 8. Modification (B) is orthorhombic, space group Pbca with a 27.646(3), b 11.366(1), c 17.252(2)Ǻ and Z = 8. The structures were solved by conventional heavy atom techniques and refined by full-matrix least- squares analyses to conventional R values of 0.037 [(A), 8845 independent reflections] and 0.028 [(B), 5291 independent reflections]. Important bond lengths [Ǻ] are Ir -P(trans to Cl ) 2.249(1) av. (A) and 2.234(1) (B), Ir -P(trans to PMe2Ph) 2.339(2) av. (A) and 2.344(1), 2.352(1) (B), Ir-Cl (trans to H) 2.492(2), 2.518(2) (A) and 2.503(1) (B) and Ir-Cl (trans to PMe2Ph)2.452(2) av. (A) and 2.449(1)(B). Differences in chemically equivalent metal- ligand bond lengths emphasize the importance of non-bonded contacts in determining those lengths.

Europium(II) Heptaphosphide EuP7 [1] Europium(II)heptaphosphid EuP7 [1]

1980 ◽  
Vol 35 (7) ◽  
pp. 824-831 ◽  
Author(s):  
Hans Georg von Schnering ◽  
Manfred Wittmann
Keyword(s):  
Chair Conformation ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Divalent Europium ◽  
Salt Melts ◽  
Tetrahedral Environment ◽  
Mineral Acids ◽  
The Eu

The novel polyphosphide EuP7 was prepared under controlled conditions by the reaction of the elements in salt melts at 750-800 K. EuP7 forms black prismatic crystals not attacked by diluted mineral acids and bases. The thermal decomposition yields EuP3 at 700 K and in further steps EuP2, Eu3P4 and EuP, respectively. According to the crystal structure as well as the electrical, optical and magnetic properties EuP7 is a semiconductor (EG = 0.9 eV; EG (vert) = 1.1 eV) with divalent europium (μ = 7.55 B.M.). The compound crystallizes in the monoclinic space group P21/n with a = 1148.8(7) pm, b = 570.0(3) pm, c = 1061.0(6) pm, and β= 106.08°(5); (X-ray diffraction data; 1479 hkl, R = 0.031). The P-atoms are connected (P-P) = 218.0-223.5 pm) to a 2-dimensional infinite polyanionic structure with homonuclear 3-bonded and 2-bonded P-atoms in the ratio 5:2. The polyanionic network contains P6-rings (chair conformation) as well as P8-rings and P10-rings. The Eu-atoms are bonded to 9 P-atoms (1,4,4-polyhedra) with bond distances ranging from 306.6 to 326.6 pm. The Eu-atoms complete the tetrahedral environment of the P-atoms

The Crystal and Molecular Structure of trans-Dichloro-mer-trans-bis (triisopropylphosphine)(phosphine)hydridoiridium(III)

1995 ◽  
Vol 48 (7) ◽  
pp. 1277 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Crystal And Molecular Structure ◽  
Structure Refinement ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Molecular Dimensions

The structure of mer-trans-(PPri3)2(PH3)H-trans-Cl2IrIII (1) (Pri = isopropyl), the second third-row transition-metal-PH3 complex to be so characterized, has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group C 2/c with a 21.701(2), b 8.735(1), c 15.594(1) Ǻ, β 119.57(1)° and Z 4. Structure refinement by full-matrix least-squares analysis (2811 reflections, 113 parameters) converged with R = 0.016 and Rw = 0.022. Molecules exhibit crystallographically imposed C2 symmetry. The C2 axis passes through the iridium, hydride and PH3 phosphorus atoms, and requires the PH3 hydrogen atoms to be disordered. Important molecular dimensions are Ir-PPri3 2.371(1) Ǻ, Ir-PH3 2.362(1) Ǻ, Ir-Cl 2.374(1) Ǻ and P- Ir -P(trans) 163.21(3)°.

The new mineral novograblenovite, (NH4,K)MgCl3·6H2O from the Tolbachik volcano, Kamchatka, Russia: mineral description and crystal structure

2018 ◽  
Vol 83 (02) ◽  
pp. 223-231 ◽  
Author(s):  
Viktor M. Okrugin ◽  
Sharapat S. Kudaeva ◽  
Oxana V. Karimova ◽  
Olga V. Yakubovich ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Refinement ◽  
Kamchatka Peninsula ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Tolbachik Volcano ◽  
Difference Fourier

AbstractThe new mineral novograblenovite, (NH4,K)MgCl3·6H2O, was found on basaltic lava from the 2012–2013 Tolbachik fissure eruption at the Plosky Tolbachik volcano, Kamchatka Peninsula, Russia. It occurs as prismatic, needle-like transparent crystals together with gypsum and halite. Novograblenovite was formed due to the exposure of the host rocks to eruptive gas exhalations enriched in HCl and NH3. Basalt was the source of potassium and magnesium for the mineral formation. Novograblenovite crystallises in the monoclinic space group C2/c, with unit-cell parameters a = 9.2734(3) Å, b = 9.5176(3) Å, c = 13.2439(4) Å, β = 90.187(2)°, V = 1168.91(2) Å3 and Z = 4. The five strongest reflections in the powder X-ray diffraction pattern [dobs, Å (I, %) (h k l)] are: 3.330 (100) (2 2 0), 2.976 (45) ($\bar{1}\; 1\; 4$), 2.353 (29) ($\bar {2}\; 2\; 4$), 3.825 (26) (2 0 2), 1.997 (25) ($\overline {4\; 2} $ 2). The density calculated from the empirical formula and the X-ray data is 1.504 g cm–3. The mineral is biaxial (+) with α = 1.469(2), β = 1.479(2) and γ = 1.496(2) (λ = 589 nm); 2Vmeas. = 80(10)° and 2Vcalc. = 75.7°. The crystal structure (solved and refined using single-crystal X-ray diffraction data, R1 = 0.0423) is based on the perovskite-like network of (NH4,K)Cl6-octahedra sharing chlorine vertices, and comprises [Mg(H2O)6]2+ groups in framework channels. The positions of all independent H atoms were obtained by difference-Fourier techniques and refined isotropically. All oxygen, nitrogen and chlorine atoms are involved in the system of hydrogen bonding, acting as donors or acceptors. The formula resulting from the structure refinement is [(NH4)0.7K0.3]MgCl3·6H2O. The mineral is named after Prokopiy Trifonovich Novograblenov, one of the researchers of Kamchatka Peninsula, a teacher, naturalist, geographer and geologist.

Crystallization and Preliminary X-ray Diffraction Analysis of Cold-Active β-Galactosidase from Arthrobacter sp. C2-2

2005 ◽  
Vol 70 (1) ◽  
pp. 124-132 ◽  
Author(s):  
Hana Petroková ◽  
Eva Vondráčková ◽  
Tereza Skálová ◽  
Jan Dohnálek ◽  
Petra Lipovová ◽  
...  
Keyword(s):  
Structure Refinement ◽  
Monoclinic Space Group ◽  
Molecular Replacement ◽  
Phase Problem ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Psychrotrophic Bacteria ◽  
Cold Active

β-Galactosidase from psychrotrophic bacteria strainArthrobactersp. C2-2 catalyzes cleavage of β-D-galactosyl moieties from β-D-galactosides and is interesting for its activity at low temperatures. Various types of crystals with dimensions of up to 0.8 mm were obtained and X-ray diffraction data up to 1.9 Å were collected. The crystals belong to the monoclinic space groupP21with unit-cell parametersa= 140.1 Å,b= 205.7 Å,c= 140.5 Å and β = 102.3°. The enzyme (molecular weight of a monomer is 111 kDa) forms hexamers in the crystal structure (one hexamer per asymmetric unit). The phase problem was solved by molecular replacement. Structure refinement is in progress.

scholarly journals Purification and crystallographic analysis of a FAD-dependent halogenase fromStreptomycessp. JCM9888

2015 ◽  
Vol 71 (8) ◽  
pp. 972-976 ◽  
Author(s):  
Yanqun Zhao ◽  
Baohua Yan ◽  
Ting Yang ◽  
Jian Jiang ◽  
Heng Wei ◽  
...  
Keyword(s):  
Model Building ◽  
Structure Refinement ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Hexahistidine Tag ◽  
Crystallization Experiments

A new FAD (flavin adenine dinucleotide)-dependent halogenase HalY fromStreptomycessp. JCM9888 was reported to be involved in the regioselective halogenation of adenine. HalY is a variant B FAD-dependent halogenase that is most similar to the halogenase PltA involved in pyoluteorin biosynthesis. This study reports the overexpression and purification of HalY with an N-terminal hexahistidine tag, followed by crystallization experiments and X-ray crystallographic analysis. HalY was purified as a monomer in solution and crystallized to give X-ray diffraction to a resolution of 1.7 Å. The crystal belonged to the monoclinic space groupP21, with unit-cell parametersa= 41.4,b= 113.4,c= 47.6 Å, α = γ = 90, β = 107.4°, and contained one monomer of HalY in the asymmetric unit, with a calculated Matthews coefficient of 2.3 Å3 Da−1and a solvent content of 46%. The structure of the halogenase CndH was used as a search model in molecular replacement to obtain the initial model of HalY. Manual model building and structure refinement of HalY are in progress.

scholarly journals The Optical Properties of Crystalline Zn3Nb2O8Nanomaterials Obtained by Hydrothermal Method

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mihaela Birdeanu ◽  
Mirela Vaida ◽  
Eugenia Fagadar-Cosma
Keyword(s):  
Hydrothermal Method ◽  
Isopropyl Alcohol ◽  
Monoclinic Space Group ◽  
Blue Color ◽  
The Novel ◽  
X Ray Diffraction ◽  
Transmission Microscopy ◽  
X Ray ◽  
Resolution Electron ◽  
Electron Transmission Microscopy

The present study is focused on the obtaining of the Zn3Nb2O8nanomaterial using the hydrothermal method and its characterization through different techniques. X-ray diffraction at room temperature revealed that a novel crystalline form of the nanomaterial forms at 1100°C belonging to monoclinic space group C2/c. Field-emission scanning electron microscopy evidenced the columnar morphology of the particle’s agglomeration and the high resolution electron transmission microscopy confirms the measured interplanar distances calculated from the X-ray diffraction experiments. Using the UV-VIS spectrum and Kubelka-Munk equations, the absorbance and the band gap for the Zn3Nb2O8nanomaterial were calculated. PL spectrum reveals a single peak at 465 nm corresponding to the blue color fluorescence. The novel crystalline nanomaterial might find applications in fluorescence covering of technical devices, due to its capacity to preserve blue fluorescence both in acrylic based paint and after embedding in isopropyl alcohol.

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