Studies on metal–acetylene complexes. VII. The molecular structure of bis(tricyclohexylphosphine)(hexafluorobut-2-yne)platinum(0)

1977 ◽  
Vol 55 (18) ◽  
pp. 3203-3210 ◽  
Author(s):  
John F. Richardson ◽  
Nicholas C. Payne
Keyword(s):  
Triple Bond ◽  
Heavy Atom ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray ◽  
A Cell ◽  
C Value ◽  
Back Angle ◽  
Heavy Atom Method ◽  
Automatic Diffractometer

The acetylene complex Pt(P(cyclo-C6H11)3)2 (F3CC≡CCF3) crystallizes in the monoclinic space group P21/c with four formula units in a cell of dimensions a = 10.902(2),b = 21.766(3), c = 19.808(3) Å, and β = 116.52(1)°. Three-dimensional X-ray data were collected on a four circle automatic diffractometer using Cu radiation. The structure was solved by the heavy atom method, and refined by full-matrix least-squares methods on F. A conventional agreement factor of 0.062 was achieved, employing 6678 observations for which I > 0. The coordination geometry at the platinum atom is essentially planar, for the acetylene triple bond makes an angle of 6.5(5)° with the plane formed by the Pt and the two P atoms. The triple bond length is 1.260(10) Å. The acetylene adopts a cis-bent geometry, with a mean bend-back angle of 45.5(8)°. The ligand is considerably perturbed upon coordination to the Pt atom, as is evident from the Δv(C≡C) value of 578 cm−1.

The Crystal Structure of KIO3.HIO3

1971 ◽  
Vol 49 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Lilian Y. Y. Chan ◽  
F. W. B. Einstein
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray ◽  
R Factor ◽  
Octahedral Environment ◽  
Distorted Octahedral ◽  
Potassium Hydrogen ◽  
A Cell ◽  
Least Squares Techniques

The crystal structure of potassium hydrogen di-iodate (bi-iodate) KIO3.HIO3 was determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.0 % for the 1392 observed reflexions. The salt crystallizes in the monoclinic space group P21/c with eight formula units in a cell of dimension a = 7.028(1) Å, b = 8.203(1) Å, c = 21.841(3) Å, β = 98.03(1)°.The iodate units are all basically pyramidal; weak interionic I—O contacts complete a very distorted octahedral environment around three iodine atoms. There is a capped octahedral (7-coordinate) environment around the remaining iodine atom. The I—O bonds are in the range 1.75–1.82 Å and the I—OH bonds are 1.91 and 1.95 Å, variations in length can be correlated with differences in the degree of involvement in (a) hydrogen bonding and (b) interaction with adjacent iodine atoms.

Crystal and Molecular Structure of Dithiocyanato(triphenylarsine)mercury(II)

1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Coordination Number ◽  
Diffraction Data ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Atom Method

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.

Crystal structures of two lactones of the bicyclo[2,2,2]octane series

1982 ◽  
Vol 35 (2) ◽  
pp. 457 ◽  
Author(s):  
RM Carman ◽  
SS Smith ◽  
CHL Kennard ◽  
G Smith ◽  
AH White ◽  
...  
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
A Cell

The crystal structures of two γ-lactones of the bicyclo[2,2,2]octane series, endo-3-carboxy-exo-5- iodobicyclo[2,2,2]octane-2,6-carbolactone (2; R = CO2H) and exo-3-methoxycarbonyl-endo-5-acetoxybicyclo[2,2,2] octane-2,6-carbolactone (7b), have been determined by direct methods from three-dimensional X-ray data and refined by least-squares to final residuals of 0.033 (2; R = CO2H) and 0.036 (7b) for 1918 and 630 'observed' reflections respectively. Crystals for (2; R = CO2H) are monoclinic, space group P21/c with Z 8 in a cell of dimensions a 7.192(2), b 23.785(8), c 13.199(5) �, β 105.35(2)�, while (7b) crystallizes in the orthorhombic space group P212121 with Z 4 in a cell of dimensions a 13.347(7), b 11.839(7), c 8.227(11) �.

Ab initio determination and Rietveld refinement of the crystal structure of Ni0.50TiO(PO4)

1999 ◽  
Vol 14 (1) ◽  
pp. 10-15 ◽  
Author(s):  
P. Gravereau ◽  
J. P. Chaminade ◽  
B. Manoun ◽  
S. Krimi ◽  
A. El Jazouli
Keyword(s):  
Crystal Structure ◽  
Ab Initio ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Heavy Atom Method

The structure of the oxyphosphate Ni0.50TiO(PO4) has been determined ab initio from conventional X-ray powder diffraction data by the “heavy atom” method. The cell is monoclinic (space group P21/c, Z=4) with a=7.3830(5) Å, b=7.3226(5) Å, c=7.3444(5) Å, and β=120.233(6)°. Refinement of 46 parameters by the Rietveld method, using 645 reflexions, leads to cRwp=0.152, cRp=0.120, and RB=0.043. The structure of Ni0.50TiO(PO4) can be described as a TiOPO4 framework constituted by chains of tilted corner-sharing TiO6 octahedra running parallel to the c axis, crosslinked by phosphate tetrahedra and in which one-half of octahedral cavities created are occupied by Ni atoms. Ti atoms are displaced from the center of octahedra units in alternating long (2.231) and short (1.703 Å) Ti–O bonds along chains.

Nitrato and Acetylacetonato Complexes of Copper(I)

1971 ◽  
Vol 49 (5) ◽  
pp. 761-766 ◽  
Author(s):  
W. A. Anderson ◽  
A. J. Carty ◽  
G. J. Palenik ◽  
G. Schreiber
Keyword(s):  
Single Crystal ◽  
Infrared Spectra ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
Synthetic Route ◽  
Tertiary Phosphine ◽  
X Ray ◽  
Tertiary Phosphines ◽  
Heavy Atom Method ◽  
Nitrate Complexes

Copper(I) nitrate complexes of the types L2CuNO3, L3CuNO3, and L4CuNO3 (L = tertiary phosphine) have been synthesized by reduction of copper(II) nitrate with tertiary phosphines. Infrared spectra and single crystal X-ray measurements indicate the presence of bidentate nitrate in L2CuNO3, monodentate nitrate in L3CuNO3, and ionic nitrate in L4CuNO3.The single crystal X-ray structure of nitratobis (tricyclohexylphosphine)copper(I) is reported. CuO3N(PC18H33)2 crystallizes in the monoclinic space group C2/c with a = 18.18(1) Å, b = 9.240(6) Å, c = 22.41(2) Å, and β = 96.57(5)°. The structure was solved by the heavy atom method and refined with isotropic thermal parameters to an R of 0.14. The copper atom is tetrahedrally coordinated by two phosphorus atoms and two oxygen atoms of a bidentate nitrate group. The P—Cu—P angle (140(1)°) and Cu—P bond lengths (2.29(1) Å) are the largest reported for tetrahedral copper complexes.A facile synthetic route to acetylacetonatobis(phosphine)copper(I) complexes is also described.

The crystal and molecular structure of di-μ-phenylthiolatobis[trichloro(dimethyl sulfide) tungsten(IV) (W—W)]

1983 ◽  
Vol 61 (12) ◽  
pp. 2809-2812 ◽  
Author(s):  
P. Michael Boorman ◽  
Joanne M. Ball ◽  
Kelly J. Moynihan ◽  
Vikram D. Patel ◽  
John F. Richardson
Keyword(s):  
Molecular Structure ◽  
Bond Length ◽  
Dimethyl Sulfide ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfide Ligands ◽  
Heavy Atom Method

The complex (Me2S)Cl3W(μ-SPh)2WCl3(SMe2), 1, has been isolated as one product of the 1:1 reaction between WCl4(Me2S)2 and SiMe3(SPh) in CH2Cl2 solution. A single crystal X-ray diffraction study shows that the molecule has the relatively unusual edge-shared bioctahedral structure, with a W—W bond length of 2.759(1) Å. The dimethyl sulfide ligands occupy positions trans to one another in the equatorial mean plane of the molecule, which has two-fold symmetry imposed on it. The structure was solved by the heavy atom method and refined to R = 0.044 and Rw = 0.058 for 2001 reflections. Crystals of 1 are monoclinic, space group C2/c, with a = 17.445(4), b = 12.594(2), c = 11.509(3) Å, β = 91.22(1)°, and Z = 4.

The Stereochemistry of Some Organic Derivatives of Group Vb Elements. Part X. The Crystal and Molecular Structure of Triphenylarsenic Difluoride

1975 ◽  
Vol 53 (11) ◽  
pp. 1647-1650 ◽  
Author(s):  
Ann Augustine ◽  
George Ferguson ◽  
Frank C. March
Keyword(s):  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Three Dimensional ◽  
Arsenic Atom ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Phenyl Rings ◽  
Derivatives Of ◽  
Heavy Atom Method

The crystal structure of triphenylarsenic difluoride has been determined from three-dimensional X-ray diffractometer data. Crystals of Ph3AsF2 are orthorhombic, space group Pbcn, with four molecules of C18H15AsF2 in a unit cell of dimensions a = 6.270, b = 16.593, c = 14.519 Å; molecular symmetry C2 is required. The structure was solved by the heavy atom method and refined by full-matrix least-squares calculations to a final residual R of 0.054 for 979 intensities regarded as "observed" (I > 3σ(I)). The crystals contain well separated discrete molecules. The arsenic atom has near regular trigonal bipyramidal geometry with apical fluorine atoms (As—F 1.834(7) Å) and equatorial phenyl rings (mean As—C 1.925(5) Å). Idealized D3 symmetry is not achieved because of unequal rotations of the phenyl rings about the As—C bonds.

Crystal structure of 9-Oxofluorene-4-carboxylic acid

1981 ◽  
Vol 34 (5) ◽  
pp. 1143 ◽  
Author(s):  
CHL Kennard ◽  
G Smith ◽  
GF Katekar
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
A Cell

The crystal structure of 9-oxofluorene-4-carboxylic acid has been determined by direct methods using three-dimensional X-ray diffraction data, and refined to R0·068 for 1323 'observed' reflections. Crystals are monoclinic, space group P21/c with 24 in a cell of dimensions a 3·843(3), b 7·986(5), c 3269(2) �, β 96·64(4)�. The molecules form centrosymmetric hydrogen-bonded cyclic dimers [O···O 2·642(3) �] with the plane of the carboxylic acid making an angle of 26·5� with that of the 9-oxofluorene group. Stacks of molecules form down the a axis with 3.843 �. separation.

The iodo-Tamoxifens: molecular structures and syntheses of estrogens for external imaging of carcinoma

1983 ◽  
Vol 61 (3) ◽  
pp. 421-426 ◽  
Author(s):  
Duncan H. Hunter ◽  
Nicholas C. Payne ◽  
Asadur Rahman ◽  
John F. Richardson ◽  
Yolanda Zea Ponce
Keyword(s):  
Three Dimensional ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
A Cell ◽  
E And Z Isomers ◽  
Unambiguous Assignment

The E- and Z-isomers of an iodo-Tamoxifen 1 (1-(p-(β-dimethylaminoethoxy)phenyl)-2-(p-iodophenyl)-1-phenyl-1-butenes) have been prepared from the corresponding E- and Z-amino-Tamoxifens 2 (2-(p-aminophenyl)-1-(p-(β-dimethylaminoethoxy)phenyl)-1-phenyl-1-butenes) and the molecular structures have been determined from three dimensional X-ray data. Crystals of E-1 are triclinic, space group [Formula: see text], with Z = 2 in a cell of dimensions a = 10.714(2), b = 14.125(3), c = 8.240(2) Å, α = 95.78(1), β = 92.91(1), and γ = 71.41(1)°; those of Z-1 are monoclinic, space group P21/n, with Z = 4 and cell dimensions a = 12.675(2), b = 19.553(3), c = 9.483(1) Å, and β = 92.22(1)°. Intensity data collected on an automated four circle diffractometer were used for full-matrix least-squares refinement on F, which converged for E-1 at R = 0.054, 2736 observations, and for Z-1 at R = 0.042, 3644 observations. The solution of these structures determines the configuration of these isomers as well as the respective amino precursors and allows an unambiguous assignment of the proton nmr spectra of 1, 2 and the Tamoxifens.

scholarly journals Crystallographic studies of SarV, a global regulator fromStaphylococcus aureus

2015 ◽  
Vol 71 (8) ◽  
pp. 1038-1041
Author(s):  
Yang Song ◽  
Fan Zhang ◽  
Xu Li ◽  
Jianye Zang ◽  
Xuan Zhang
Keyword(s):  
Heavy Atom ◽  
Size Exclusion ◽  
Monoclinic Space Group ◽  
Molecular Replacement ◽  
Global Regulator ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Exclusion Chromatography ◽  
Heavy Atom Method

SarV, a member of the SarA protein family, is a global transcriptional regulator which has been reported to be involved in the regulation of autolysis inStaphylococcus aureus. In this study, SarV fromS. aureuswas successfully cloned, expressed, purified and crystallized. X-ray diffraction data were collected to 2.10 Å resolution. The crystals of SarV belonged to the monoclinic space groupP21, with unit-cell parametersa= 36.40,b= 119.64,c= 66.80 Å, α = γ = 90, β = 98.75°. The Matthews coefficient and the solvent content were estimated to be 2.57 Å3 Da−1and 52%, respectively, suggesting the presence of four molecules in the asymmetric unit. The results of size-exclusion chromatography (SEC) indicated thatS. aureusSarV exists as a homodimer in solution. Unfortunately, the structure cannot be solved by molecular replacement because of the low sequence identity ofS. aureusSarV to known structures. Further phase determination by selenomethionine single-wavelength anomalous dispersion (SAD) and the heavy-atom method is in progress.

Sign in / Sign up

Export Citation Format

Share Document