Coordinated fluoride in rhenium(I) carbonyl complexes

1984 ◽  
Vol 37 (1) ◽  
pp. 35 ◽  
Author(s):  
E Horn ◽  
MR Snow
Keyword(s):  
Hydrogen Bonding ◽  
Least Squares ◽  
Mass Spectra ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Carbonyl Complexes ◽  
Full Matrix ◽  
Space Group ◽  
Corrected Data ◽  
R Value

Bromide abstraction from the complexes Re(CO)3L2Br (where L = SbPh3 and L2 = bpy, dpe, tmen)* by AgF2H gives the corresponding fluoro compounds Re(CO)3L2F. Mass spectra and structural data show that the fluoride in these complexes is coordinated to the metal. The structures of Re(CO)3(tmen)F and [Re(CO)3(tmen)F]2H.HOBF3 are reported here. Crystals of Re(CO)3(tmen)F are monoclinic, space group P21/c, with a 8.202(2), b 13.115(9), c 12.048(4) � and β 102 24(3)�. A full-matrix least-squares refinement by using the absorption corrected data gave a conventional R value of 0.041. [Re(CO)3(tmen)F]2H.HOBF3 also crystallizes in the space group P21/c. The lattice parameters are: a 17.495(2), b 10.772(2), c 15.447(1) � and β ( 101.409(8)�. The final R value of a blocked least-squares calculation converged at 0.061. In these two complexes the simple Re-F distance is 2.040(4) �, in Re(CO)3(tmen)F. The Re-F distance is increased to 2.236(10)�, as a result of hydrogen bonding between the fluoride and HOBF3 in the latter compound.

Studies in aryltin chemistry. Part 6. Crystal and molecular structures of tetra(p-methylsulphonylphenyl)tin(IV) and tetra(p-methylsulphinylphenyl)tin(IV) monohydrate

1990 ◽  
Vol 68 (8) ◽  
pp. 1277-1282 ◽  
Author(s):  
Ivor Wharf ◽  
Michel G. Simard ◽  
Henry Lamparski
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Direct Method ◽  
Molecular Structures ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Molecular Symmetry ◽  
Asymmetric Unit ◽  
Full Matrix ◽  
Space Group

Tetrakis(p-methylsulphonylphenyl)tin(IV) and tetrakis(p-methylsulphinylphenyl)tin(IV) n-hydrate have been prepared and their spectra (ir 1350–400 cm−1; nmr, 1H, 13C, 119Sn) and X-ray crystal structures are reported. The first compound is monoclinic, space group C2/c, Z = 4, with a = 21.589(6), b = 6.207(3), c = 22.861(11) Å, β = 93.80(3)° (22 °C); the structure was solved by the direct method and refined by full-matrix least squares calculations to R = 0.043 for 2755 observed reflections. It has 2 molecular symmetry with the methyl group and one oxygen atom completely disordered in both CH3S(O2) groups in the asymmetric unit. The second compound is tetragonal, space group P42/n, Z = 2, with a = b = 15.408(6), c = 6.379(2) Å (−100 °C); the structure was solved by the Patterson method and refined by full-matrix least squares calculations to R = 0.060 for 1209 observed reflections. It has [Formula: see text] molecular symmetry with the whole asymmetric unit disordered. Water molecules occupy positions on parallel 42 axes but molecular packing requirements prevent all sites having 100% occupancy giving n ~ 1 for the hydrate. Keywords: Tetra-aryltins, crystal structures, sulphone, sulphoxide, hydrogen-bonding.

Magnetic, Spectral and Structural Aspects of Spin Transitions in Iron(II) Complexes of 2-(Pyrazol-3-yl)pyridine and 3-(Thiazol-2-yl)pyrazole

1999 ◽  
Vol 52 (2) ◽  
pp. 109 ◽  
Author(s):  
Lucia S. Harimanow ◽  
Kristian H. Sugiyarto ◽  
Donald C. Craig ◽  
Marcia L. Scudder ◽  
Harold A. Goodwin
Keyword(s):  
Hydrogen Bonding ◽  
Hysteresis Loop ◽  
Room Temperature ◽  
Thermal Hysteresis ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Thermal Hysteresis Loop ◽  
Lower Temperature ◽  
Structural Aspects

Tris(ligand)iron(II) complexes of 2-(pyrazol-3-yl)pyridine (3ppH) and 3-(thiazol-2-yl)pyrazole (3tpH) undergo temperature-induced singlet (1A1) ⇔ quintet (5T2) transitions. The transition in [Fe(3ppH)3] [CF3SO3]2.2H2O is continuous and centred above room temperature while that in the anhydrous triflate salt is discontinuous and is centred below room temperature. The latter transition occurs via a thermal hysteresis loop of width 12 K, Tc↓ and Tc↑ being 229 and 241 K, respectively. The displacement of the transition to lower temperature in the anhydrous salt is believed to be associated with the loss of hydrogen bonding involving the uncoordinated pyrazole >NH group and solvate water. In [Fe(3tpH)2(3tp)] [ClO4].2H2O and [Fe(3tpH)2(3tp)] [BF4].2H2O (3tp is the deprotonated ligand) continuous transitions are observed, centred below room temperature. In these instances the displacement is consistent with the intrinsically weaker field of the bidentate system containing two five-membered heterocycles. Structural data were obtained for [Fe(3ppH)3][CF3SO3]2.2H2O, [Fe(3tpH)3] [BF4]2.1·5H2O and [Ni(3tpH)3] [BF4]2.2(3tpH). The average metal–nitrogen distances in the complexes are 1·97, 2·18 and 2·09 Å, severally. The large difference in the distances for the two iron complexes arises from the different ground states: a singlet for the 3ppH complex and a quintet for the 3tpH complex. In all three salts there is extensive hydrogen bonding involving the pyrazole >NH groups, the anions and the solvate molecules. [Fe(3ppH)3] [CF3SO3]2.2H2O: monoclinic, space group P21/c, a 12·33(1), b 24·44(1), c 12·55(1) Å, β 115·27(4)°, Z 4. [Fe(3tpH)3] [BF4]2.1·5H2O: monoclinic, space group C 2/c, a 41·56(2), b 16·418(3), c 18·154(7) Å, β 106·94(2)°, Z 8. [Ni(3tpH)3] [BF4]2.2(3tpH):P bcn, a 14·928(2), b 15·310 (3), c 17·882 (3) Å, Z 4.

The crystal and molecular structure of anti-1,2,4,5-tetraphenyl-3,6-dicarbomethoxytricyclo[3.1.0.02,4]hexane

1978 ◽  
Vol 56 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
M. J. Bennett ◽  
J. T. Purdham
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Experimental Error ◽  
Crystal And Molecular Structure ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Bond Lengths ◽  
Highly Strained ◽  
Least Squares Techniques

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.

scholarly journals Synthesis and Molecular Structure of cis-Tetracarbonyl[N-(diphenylphosphino-kP)-naphthalen-1-yl-P,P-diphenylphosphinous amide-kP]chromium(0)

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Harbi Tomah Al-Masri
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Molar Ratio ◽  
Planar Geometry ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
Distorted Octahedral ◽  
Least Squares Techniques

The reaction of N,N-bis(diphenylphosphanyl)naphthylamine C10H7-1-N(PPh2)2 with (C5H10NH)2Cr(CO)4 (1 : 1 molar ratio) in dichloromethane afforded cis-[Cr(CO)4{C10H7-1-N(PPh2)2}] (1). This complex was crystallized in the monoclinic space group P21/n. The structure was solved by direct methods and refined by full-matrix least squares techniques to an R factor of 0.0313 for 6488 observed reflections. The Cr-metal is coordinated by four terminal CO molecules and a P,P′-bidentate N,N-bis(diphenylphosphanyl)naphthylamine ligand in a distorted octahedral array. The N-atom adopts a planar geometry with the two P-atoms and C-atom attached to it. The four-membered metallacycle ring P2CrN is nearly planar.

Refinement of the structure of Mg2As2O7

1970 ◽  
Vol 48 (6) ◽  
pp. 890-894 ◽  
Author(s):  
C. Calvo ◽  
K. Neelakantan
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Unit Cell ◽  
Full Matrix ◽  
Space Group ◽  
Cell Dimensions ◽  
Central Oxygen ◽  
R Value ◽  
Unit Cell Dimensions

The crystal structure of Mg2As2O7 has been refined by full matrix least squares procedures using 587 observed reflections. The structure of Mg2As2O7 is of the thortveitite type, as reported by Łukaszewicz, with space group C2/m and unit cell dimensions a = 6.567(2) Å, b = 8.524(4) Å, c = 4.739(1) Å, β = 103.8(1)°, and Z = 2. The As—O—As group in the anion appears to be linear but the central oxygen atom undergoes considerable disorder in the plane perpendicular to this group. The AsO bond distances uncorrected for thermal motion are 1.67 Å for the As—O(—As) bond and 1.66 and 1.65 Å for the terminal As—O bonds. The final R value obtained is 0.088.

The Structure of Na4P2O7 at 22 °C

1972 ◽  
Vol 50 (16) ◽  
pp. 2519-2526 ◽  
Author(s):  
K. Y. Leung ◽  
C. Calvo
Keyword(s):  
Least Squares ◽  
Room Temperature ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
R Value ◽  
Automatic Diffractometer ◽  
Oxygen Atoms

At room temperature Na4P2O7 crystallizes in the orthorhombic space group P212121 with a = 9.367(5), b = 5.390(2), c = 13.480(8) Å, and z = 4. The structure was refined by full-matrix least-squares using 1337 reflections measured with a Syntex Automatic diffractometer. The final R value is 0.022. The anion has nearly an eclipsed configuration with a P—O—P angle of 127.5(1)°. The two bridging P—O bond lengths are 1.631(2) and 1.642(2) Å with terminal P—O bond lengths averages of 1.512 and 1.514 Å on either side of the anion. Two of the four Na+ ions are coordinated to five oxygen atoms while the remainder are coordinated to six oxygen atoms. The structure contains chains of cations with four nearly collinear Na+ per cell paralleling the c axis. These are surrounded by six anions with the bridging oxygen atoms lying approximately at the corners of an octahedron with the P—P vector of the anion also paralleling the c axis. Adjacent anions along the c axis are separated by a pair of Na+ ions.

Structural Systematics of Metal Acetylide Complexes. II. X-Ray Studies of Some Nickel σ-Acetylide Complexes

1998 ◽  
Vol 51 (3) ◽  
pp. 219 ◽  
Author(s):  
Ian R. Whittall ◽  
Mark G. Humphrey ◽  
David C. R. Hockless
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Trans Influence

The structures of Ni(C≡CR)(PPh3)(η-C5H5) (R = Ph (1), C6H4-4-NO2 (2), 4-C6H4C6H4-4′-NO2 (3), (E)-4-C6H4CH=CHC6H4-4′-NO2 (4), 4-C6H4C≡CC6H4-4′-NO2 (5), 4-C6H4N=CHC6H4-4′-NO2 (6)) have been determined by single-crystal X-ray diffraction studies, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a 10·094(2), b13·429(3), c 18·835(5) Å,α 103·24(2), β 91·50(2), γ 90·10(2)°, Z 4, 5844 unique reflections (595 parameters), converging at R 0·033 and Rw 0·024. For (2), crystals are orthorhombic, space group Pna21, with a 16·799(2), b 8·681(2), c 17·485(2) Å, Z 4, 1774 unique reflections (325 parameters), converging at R 0·031 and Rw 0·029. For (3), crystals are monoclinic, space group P 21/c, with a 11·140(3), b 18·282(4), c 15·296(2) Å, β 105·18(2)°, Z 4, 3132 unique reflections (397 parameters), converging at R 0·039 and Rw 0·024. For (4), crystals are monoclinic, space group P 21/n, with a 12·929(7), b 16·953(8), c 15·601(7) Å, β 112·55(3), Z 4, 3023 unique reflections (397 parameters), converging at R 0·039 and Rw 0·025. For (5), crystals are monoclinic, space group P 21/n, with a 12·710(5), b 16·882(3), c 15·693(4) Å, β 111·37(3)°, Z 4, 3216 unique reflections (397 parameters), converging at R 0·035 and Rw 0·030. For (6), crystals are monoclinic, space group P 21/n, with a 12·594(1), b 16·936(2), c 15·611(1) Å, β 112·476(5)°, Z 4, 3564 unique reflections (397 parameters), converging at R 0·038 and Rw 0·041. For structurally characterized 18-electron (cyclopentadienyl)nickel(II) acetylide complexes, statistically insignificant decreases in the average Ni-C(1) distance and trans influence and an increase in the average C(1)-C(2) parameter are observed on introduction of an acceptor substituent at the alkynyl ligand.

The Structure of Thiobinupharidine

1973 ◽  
Vol 51 (17) ◽  
pp. 2810-2820 ◽  
Author(s):  
J. T. Wróbel ◽  
B. Bobeszko ◽  
T. I. Martin ◽  
D. B. MacLean ◽  
N. Krishnamachari ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Absolute Configuration ◽  
Spectroscopic Properties ◽  
Relative Configuration ◽  
Full Matrix ◽  
Space Group ◽  
R Value ◽  
Least Squares Techniques

The spectroscopic properties of thiobinupharidine and its isomer, neothiobinupharidine, of established structure, have been examined and compared. From this study it was possible to deduce the structure and relative configuration of the alkaloid. The structure has been firmly established and the absolute configuration determined by the study of the crystal structure of thiobinupharidine dihydrobromide dihydrate, C30H42O2N2S•2HBr•2H2O. The crystals are orthorhombic with space group C2221, a = 25.128(6), b = 9.869(2), c = 26.380(6) Å, and Z = 8. The structure was refined, using full-matrix least-squares techniques with 1934 reflections, to a final R value of 0.097. The thiobinupharidine moiety hydrogen bonds to one of two types of H2O–Br–H2O spiral chains in the structure. The tetrahydrothiophene ring is distorted from planarity, and this together with the nonequivalence of the S and C atoms in the ring causes the molecule to deviate from C2 symmetry

The Crystal and Molecular Structure of Chloro-mer-Tris(dimethylphenylphosphine)-cis-dihydridoiridium(III) by X-Ray and Neutron Diffraction

1988 ◽  
Vol 41 (5) ◽  
pp. 641 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Molecular Structure ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
Neutron Data ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The structure of mer-(Pme2Ph)3Cl-cis-H2IrIII (1) has been determined by single-crystal X-ray and neutron diffraction analyses. Crystals are monoclinic, space group P21, with a 11.476(4), b 14.069(5), c 8.286(3)Ǻ, β 92.45(1)° and Z 2. Full-matrix least-squares analyses converged 0.022 for 7773 X-ray data and R(F2) = 0.062 for 1538 neutron data. Ir -H [1.557(11)Ǻ trans to Cl, 1.603(10) Ǻ trans to P] and Ir -P distances [2.292(1)Ǻ trans to P, 2.328(1)Ǻ trans to H] both exhibit trans lengthening effects. Consistent with the increased hydride content the Ir -P distances in (1) are c. 0.04 Ǻ shorter than for the corresponding bonds in its dichloro monohydrido analogues and c. 0.08 Ǻ shorter than those in the trichloride . In contrast Ir-Cl [2.505(1)Ǻ] is not significantly different to the corresponding distance (2.504 Ǻ av.) in mer -(PMe2Ph)3-cis-Cl2HIrIII.

Alchemists' Gold, Hg2.86 Asf6; An X-Ray Crystallographic Study of A Novel Disordered Mercury Compound Containing Metallically Bonded Infinite Cations

1974 ◽  
Vol 52 (5) ◽  
pp. 791-793 ◽  
Author(s):  
I. David Brown ◽  
Brent D. Cutforth ◽  
Colin G. Davies ◽  
Ronald J. Gillespie ◽  
Peter R. Ireland ◽  
...  
Keyword(s):  
Least Squares ◽  
Lattice Parameters ◽  
Mercury Compound ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Crystallographic Study ◽  
Formal Charge ◽  
R Value

The compound Hg2.86 AsF6 belongs to the tetragonal space group I41/amd with lattice parameters a = 7.538(4) Å, c = 12.339(5) Å, and Z = 4. The structure was refined using 109 symmetry independent reflections by full matrix least-squares refinement to a final R value of 0.079. The structure may be described as consisting of octahedral AsF6− ions arranged on a lattice which contains linear, non-intersecting channels in two mutually perpendicular directions. Within these channels are infinite chains of mercury atoms, each with a formal charge of +0.35, and with a mercury–mercury distance of 2.64(1) Å.

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