scholarly journals Crystal and Molecular Structure of Platinum(II) Complex with Bis(Diphenyl Phosphino)Methane

2019 ◽  
Vol 35 (5) ◽  
pp. 1546-1549
Author(s):  
Karwan Omer Ali ◽  
Hikmat Ali Mohammad ◽  
Thomas Gerber ◽  
Eric Hosten

Platinum(II) complex consisting of the tertiarydiphosphine (dppm) ligand had been prepared from PdCl2 with one equiv. of dppm ligand to form [PtC2(dppmCl)] complex where as dppmCl is bis(dipheny1phosphino) chloromethene. Crystal was grown in dichloromethane by slow evaporation process and characterized by X-ray crystallography technic. The complex structure synthesized based upon the identification using X-ray Crystallography and FTIR was [PtC12(dppmCl)], the ligand dppm coordinated to the meta centre as bidentate chelating ligand and form square planar arrangement around Pt(II) metal centre. The bond distances of Pt-P1, Pt-P2, Pt- Cl1 and Pt-Cl2 are 2.217 (2), 2.217 (2), 2.3661 (19) and 2.3661 Aο respectively. The characterized results of Pt(II) complex using X-ray analysis illustrated that [PtC12(dppmCl)] Complex form monoclinic crystal with unit cell dimensions of a = 16.2034(5), b = 7.8274(2), and c = 19.2496 (6) Aο, with β = 98.918 (1)ο, Z=4, calculated density= 1.838 mg/m3, T= 200 k and space group C2/c

1995 ◽  
Vol 50 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Mathias O. Senge ◽  
Karin Ruhlandt-Senge ◽  
Kevin M. Smith

The crystal and molecular structure of chloro(methyl phytochlorinato)iron(III), 4, have been determined by single crystal X-ray crystallography to obtain further information on the conformation of metallochlorins related to chlorophyll. The compound crystallized with two independent molecules mainly distinguished by the orientation of the axial ligand. The macrocycles show significant deviations from planarity larger than those observed in corresponding magnesium(II) complexes. The overall type of distortion is similar to those found in chlorophyllides. Compound 4 crystallized in the monoclinic space group P21 (MoKa,λ = 0.71063 A) with unit cell dimensions a = 12.035(6) Å, b = 13.396(8) Å, c = 19.04(2), b = 97.51(2) Å, Z = 4, V = 3043(4) Å3. The structure was refined to an R-value of 0.075 on the basis of 3974 reflections with I > 3.0σ(Ι) (130 Κ).


1981 ◽  
Vol 46 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Viktor Kettman ◽  
Ján Garaj ◽  
Jaroslav Majer

The crystal and molecular structure of [Cr(S2CN(CH2)5)3].2 CHCl3 was found by the X-ray structural analysis method. The value R 0.090 was found for 1 131 observed independent reflections. The substance crystallizes in a space group of symmetry P212121 with the following unit cell dimensions: a = 0.8675 (6), b = 1.815(2), c = 2.155(3) nm. The experimentally observed crustal density was 1.48 Mgm-3 and the value calculated for Z = 4 was 1.51 Mgm-3. The CrS6 coordination polyhedron has the shape of a trigonally distorted octahedron, where the D3 symmetry is a approximately retained. The degree of trigonal distortion expressed as the projection of the chelate S-Cr-S angle onto the plane perpendicular to the C3 pseudo axis is Φ = 41.7° (Φ = 60° for an octahedron). The skeleton of the structure formed by the complex molecules contains channels filled with chloroform molecules. The specific type of complex-chloroform interaction consists of the formation of hydrogen bonds of the chloroform protons with the fully occupied pπ-orbitals of the sulphur atoms in the coordination polyhedra. The low stability and crystal decomposition can be explained by loss of chloroform from the channels.


1989 ◽  
Vol 44 (5) ◽  
pp. 575-581 ◽  
Author(s):  
Giuliano Bandoli ◽  
Umberto Casellato ◽  
Mario Gleria ◽  
Antonio Grassi ◽  
Enzo Montoneri ◽  
...  

The crystal and molecular structure of [NP(OC10H7)2]3 was determined by X-ray analysis.The dipole moments of this compound and of the hexa(phenoxo)cyclotriphosphazatrienes of formula [NP(OC6H3XX′Y)2]3 (X = X′ = H, Y = p-Br; X = m-CH3,. X′ = H. Y = p-Cl; X = X′ = m-CH3, Y = p-Cl; X = X′ = m-CH3, Y = H; X = X′ = H, Y = p-CH(CH3)2; X = X′ = H, Y = p-C(CH3)3) were measured in benzene at 25°C. Crystals of [NP(OC10H7)2]3 are monoclinic with unit cell dimensions a = 24.870(15), b = 7.712(8), c = 27.687(14) Å, β = 115.85(7)°; space group P21/c. The structure was refined to an agreement factor of 0.09. The phosphazene ring deviates (max. deviation 17°) from planarity. and mean distances (A) and angles (°) are P-N 1.58(1). P-O 1.58(1), O-C 1.41(2); P-N-P 120(1), N-P-N 119(1), P-O-C 124(2). The conformations of the naphthyloxo groups at P(2) and P(3) are similar, and different from the group at P(1).Dipole moment analysis showed that the solid state conformation changes in the solution state. The measured value was in agreement with a symmetric conformation in which at the O-P-O plane each naphthyloxo group is rotated by ca. 40-50° from the anti-coplanar arrangement relative to this plane. The dipole moment data for the p-substituted phenoxo derivatives agree with such a conformation, but the analysis of the dipole moment values of phosphazenes having phenoxo groups bearing more than one substituent group and p-CH(CH3)2 substituent failed to do so due to the inherent limitations of the method.


Author(s):  
Sven Hovmöller ◽  
Linus Hovmöller Zou ◽  
Xiaodong Zou ◽  
Benjamin Grushko

Quasi-crystals shocked the crystallographic world when they were reported in 1984. We now know that they are not a rare exception, and can be found in many alloy systems. One of the richer systems for quasi-crystals and their approximants is Al−Co−Ni. A large series of pseudo-decagonal (PD) approximants have been found. Only two of them, PD4 and PD8, have been solved by X-ray crystallography. We report here the structures of PD1, PD2, PD3 and PD5, solved from the limited information that is provided by electron diffraction patterns, unit cell dimensions and high-resolution electron microscopy images.


2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å


2014 ◽  
Vol 70 (a1) ◽  
pp. C442-C442
Author(s):  
Anson Chan ◽  
Yanjie Liu ◽  
Kris Blair ◽  
Emilisa Frirdich ◽  
Erin Gaynor ◽  
...  

The bacterial cell wall is a polymeric structure that determines the overall shape of the cell and undergoes constant remodelling during cell growth, requiring enzymes that cleave the existing peptidoglycan structure. Csd4 is an enzyme important for cell shape as deleting it in Helicobacter pylori causes the helical-shaped cells to become rod-like. Csd4 is a zinc carboxypeptidase that can cleave the tripeptide moiety found in peptidoglycan (i.e. L-Ala-γ-D-Glu-m-DAP) to release meso-diaminopimelic acid (mDAP). Structures of Csd4 were solved by X-ray crystallography up to 1.75 Å resolution in space group P212121 with zinc and substrate/product bound and contain the same unit cell dimensions. Csd4 is a monomeric enzyme with three domains: an N-terminal M14-family carboxypeptidase domain followed by two smaller domains likely important in protein-protein or protein-peptidoglycan interactions. Key interactions are observed between the protein and substrate in the active site, supporting specific substrate recognition by Csd4. A water or hydroxide molecule, which is required for catalytic activity, is also observed bound to the zinc and is poised to interact with the substrate molecule upon activation.


2006 ◽  
Vol 61 (1) ◽  
pp. 61-64
Author(s):  
Ludmila Vigo ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen

The synthesis and structure of (C4H3S)TeCH2CH2OC6H5 (1) (C4H3S = thiophen-2-yl) are reported and compared to those of the analogous selenium compound (C4H3S)SeCH2CH2OC6H5 previously synthesized by our group. The compound was characterized by 1H, 13C{1H}-, and 125Te- NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21, with Z = 2, and unit cell dimensions a = 10.618(2) Å , b = 5.357(1) Å , c = 10.684(2) Å , β = 96.57(3)°. The lattice is composed of discrete molecules that are joined together by weak hydrogen bonds into a three-dimensional network. The thiophen-2-yl ring is disordered and shows two alternative orientations with the site occupation factors of 0.70(1) and 0.30(1). All bond parameters are quite normal. The comparison of the lattices in 1 and in its selenium anologue shows that while the closest intermolecular contacts are similar, the packing of the molecules is different.


1992 ◽  
Vol 7 (3) ◽  
pp. 166-168
Author(s):  
J.M. Amigó ◽  
L.E. Ochando ◽  
M.M. Reventós ◽  
J. García-Lozano ◽  
L. Soto-Tuero

AbstractMetal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.


1989 ◽  
Vol 54 (3) ◽  
pp. 684-690 ◽  
Author(s):  
Jan Lokaj ◽  
Viktor Vrábel ◽  
Eleonóra Kellö ◽  
Vladimír Ratay

The crystal and molecular structure of Bu3Sn(pyrn-dtc-prop) was solved by the X-ray structural analysis method and refined by the block diagonal least squares method to R = 0.053 for 1 930 observed reflections. The compound crystallizes in the monoclinic system with a space group of P21/c, Z = 4, F(000) = 1 056, with unit cell dimensions of a = 1.4758(5), b = 0.9970(3), c = 1.9166(6) nm; β = 113.90(2)°. The measured and calculated crystal densities were Dm = 1.32 and Dc = 1.31.103 kg m-3. The tin atom is coordinated by three carbon atoms at distances of Sn-C 0.2117(8), 0.2133(8), 0.2158(11) nm and two oxygen atoms O(1) and O(2) at distances of Sn-O 0.2210(5) and 0.2399(5) nm. The coordination polyhedron is a deformed trigonal bipyramid. The S2CN ligand is approximately planar.


Author(s):  
Janet Vonck ◽  
Ernst F.J. van Bruggen

Several yeast species are able to grow on methanol. When they are grown in a methanol-restricted culture, their peroxisomes contain large crystalline inclusions, consisting of alcohol oxidase (AOX). A monomer of AOX has a molecular weight of ca. 74,000. Inside the peroxisome, AOX occurs as octamers.Electron microscopic studies of AOX from Hansenula polymorpha have revealed that the eight subunits are slightly elongated and form two layers of four, which are twisted relative to each other. The molecule measures ca. 12 nm in all directions.Recently, crystals suitable for x-ray diffraction have been formed of AOX from Pichia pastoris . The space group is P21, with unit cell dimensions a=157.3Å, b=171.45Å, c=231.6Å, β=94°. These dimensions indicate that the unit cell contains four octamers, too much to solve by x-ray crystallography alone. Therefore, we have started an EM study of the crystals, to get information about the organization of the molecules in the crystal lattice.


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