The Structure and Physical Properties of μ-oxo-bis{oxotrichloro(O-perrhenylchloride)rhenium(VI)}, and the Non-existence of β-ReOCl3

1972 ◽  
Vol 50 (22) ◽  
pp. 3607-3618 ◽  
Author(s):  
C. Calvo ◽  
P. W. Frais ◽  
C. J. L. Lock

The compound previously reported as β-ReOCl3 has been shown by analysis and single crystal X-ray diffraction to be μ-oxo-bis{oxotrichloro(O-perrhenyl chloride)rhenium(VI)}, (Re2O3Cl6)(ReO3Cl)2. The crystals were triclinic, a = 6.112(5), b = 12.876(9), c = 6.020(5) Å, α = 88.30(5), β = 95.88(5), γ = 105.36(5)°, [Formula: see text]. Intensities were measured by a densitometer from photographs recorded on an integrating precession camera. The structure was refined by full matrix least squares to give a final R2 of 0.072. The molecule is composed of a dimeric Re2O3Cl6 unit with a bridging oxygen atom on the center of symmetry and an Re—O (bridge) distance of 1.847(1) Å. The remaining oxo-group on each rhenium is cis to the bridge and is strongly bonded (1.69(2) Å), and the position trans to the terminal oxo-group is filled by a weak bond to an oxygen atom of a perrhenyl chloride molecule. The infrared spectrum of the compound has been explained in terms of the structure.

1972 ◽  
Vol 50 (12) ◽  
pp. 1811-1818 ◽  
Author(s):  
P. W. Frais ◽  
C. J. L. Lock

Oxotetrachloroaquorhenium(VI), ReOCl4•H2O, has been prepared and characterized for the first time by analysis, infrared spectroscopy and single crystal X-ray diffraction. The crystals were orthorhombic, a = 10.834(8), b = 11.089(8), c = 5.517(4) Å, Pn21a, Z = 4. Intensity data were recorded by integrating film methods and measured with a Joyce–Loebl microdensitometer, and 624 observable of the 704 measured independent reflections were given non-zero weight in the final cycle of full matrix least-squares refinement where R1 = 0.0572 and R2 = 0.0687. The molecular structure is based on a very distorted octahedron with a strongly bonded oxo-group (Re—O, 1.63(2) Å) trans (177(2)°) to a weakly bonded aquo-group (Re—O, 2.27 (2) Å). The Re—Cl distances do not differ significantly (2.29(1) Å av). The chlorine atoms are bent away from the oxo-group (angles vary from (94–102°(1)).


1998 ◽  
Vol 51 (3) ◽  
pp. 219 ◽  
Author(s):  
Ian R. Whittall ◽  
Mark G. Humphrey ◽  
David C. R. Hockless

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.


1984 ◽  
Vol 37 (8) ◽  
pp. 1763
Author(s):  
IR Castleden ◽  
LM Engelhardt ◽  
SR Hall ◽  
AH White

The crystal structure of 8-hydroxy-1H-naphtho[2,1,8-mna]xanthen-1-one, C19H10O3, obtained as an indefinite methanolsolvate, has been determined at 295K by single-crystal X-ray diffraction methods, being refined by full matrix least squares to a residual of 0.056 for 892 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 5.128(4), b 10.024(9), c 27.45(2) �, β 107.73(6)�, Z 4. The packing of the molecules is typically that of charge-transfer complexes, with an interplanar spacing of c.3.5 �.


1984 ◽  
Vol 37 (5) ◽  
pp. 921 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White

The crystal structures of the title compounds, [Ni(OH2)4(en)] [SO4].2H2O, (1), and [Ni(OH2)4(bpy)]- [SO4].2H2O, (2), have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full matrix least-squares methods to residuals of 0.028,0.031 for 1852, 4323 independent 'observed' reflections respectively. Crystals of (1) are monoclinic, C2/c, a 9.459(4), b 12.192(7), c 12.294(3) �, β 119.84(4)�, Z 4. In the cation, Ni-N is 2.061(2) �; Ni-O (trans to O, N respectively) are 2.106(2), 2.063(2) �. Instead of being enlarged above 90� as predicted from repulsion theory, the angle between the pair of oxygen atoms trans to nitrogen is diminished, being 87 14(7)�. Crystals of (2) are triclinic, P1, a 11.476(5), b 9.351(5), c 7.793(4) �, α 77.63(4), β 83.52(3), γ87.40(4)�, Z 2. In the cation, Ni-N are both 2.063(2) �. Ni-O (trans to N, O respectively) are 2.060(2), 2.O42(2); 2.O80(2), 2�. The short Ni-O distance [2.042(2)�] is associated with the coordination of a trigonal water molecule.


1973 ◽  
Vol 51 (13) ◽  
pp. 2073-2076 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan

One of the compounds obtained by reacting acetylacetone with oxoethoxodichlorobis(triphenylphosphine)rhenium(V) has been shown by single crystal X-ray diffraction to be trans-dichlorobis(pentane-2,4-dionato)rhenium(IV). The crystals are triclinic, a = 8.032(4), b = 8.344(6), c = 7.429(6) Å, α = 118.1(2), β = 92.3(2), γ = 55.5(2)°, [Formula: see text], Z = 1. Intensities were measured with a microdensitometer from photographs recorded on an integrating precession camera. Of the 991 measured reflections all were observed and 984 were used in the refinement. The structure was refined by full matrix least squares to an R2 value of 0.0685. The compound was found to be a trans-monomer, in contrast to the dimeric structure claimed to exist in solution. The ligand atoms bonded to rhenium lie almost exactly at the apices of an octahedron and the bond lengths (Re—Cl, 2.326(8); Re—O1, 1.97(1); Re—O2, 2.01(1) Å) are in the range expected.


1978 ◽  
Vol 31 (9) ◽  
pp. 1927 ◽  
Author(s):  
DL Kepert ◽  
CL Raston ◽  
NK Roberts ◽  
AH White

The crystal structure of the title compound, [Tl(S2CNEt2)3], has been determined by single-crystal X-ray diffraction methods at 295 K and refined by full-matrix least squares to a residual of 0.050 for 2517 'observed' reflections. Crystals are monoclinic, with space group A2/a, a 14.789(7), b 10.428(4), c 18.207(9) Ǻ, β 118.11(4)°, Z 4, and are isostructural with those of the previously determined gallium and indium analogues, the molecule having 2 symmetry with <Tl-S> 2.666 Ǻ. As in the dimethyl/thallium analogue, the departure of the TlS6 core symmetry from 3 is large and is examined in terms of electron-pair repulsion theory.


1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.


1981 ◽  
Vol 34 (6) ◽  
pp. 1223 ◽  
Author(s):  
RA Russell ◽  
DE Marsden ◽  
M Sterns ◽  
RN Warrener

A new potential synthesis of anthraquinones based upon 1-acetoxyisobenzofuran (4) is reported. The key reaction used to generate isobenzofurans, namely the s-tetrazine reaction, proceeds smoothly in the presence of N-methylmaleimide to yield the expected adduct (16). In contrast, the reaction takes a different path in the presence of quinones to yield a novel phthalide (15). These reactions are considered to involve a non-concerted fragmentation of the intermediate dihydro-pyridazine (3) to yield the stabilized zwitterionic species (13). The zwitterion leads on to the phthalide (15) in a two step sequence involving the quinone as oxidant, while normal fragmentation is the sole reaction in the absence of oxidant. ��� The structure of 3-[3',6'-di(pyridin-2''-yl)pyridazin-4'- yl]isobenzofuran-1(3H)-one (15) has been determined by single crystal X-ray diffraction and refined by full-matrix least squares to a residual of 0.107 for 1389 'observed' reflections. Crystals are monoclinic, P21/c, a 8.271(2), b 19.183(4), c 11.814(2)Ǻ, β 110.0(1)β.


1978 ◽  
Vol 31 (12) ◽  
pp. 2717 ◽  
Author(s):  
BN Figgis ◽  
CL Raston ◽  
RP Sharma ◽  
AH White

The crystal structure of the title compound, (NH4)2 [FeCl5(H2O)], has been redetermined by single-crystal X-ray diffraction at 295 K and refined by full matrix least squares to a residual of 0.054 for 1662 'observed' reflections. Crystals are orthorhombic, Pnma, a 13.706(2), b 9.924(1), c 7.024(1)Ǻ Z 4. Fe-O is 2.110(4)Ǻ; Fe-Cl range between 2.323(1)Ǻ (trans to OH2) and 2.350(1)-2.390(1) Ǻ (cis), the latter distances being very dependent upon hydrogen-bonded interactions with nearby species.


1995 ◽  
Vol 48 (5) ◽  
pp. 1045 ◽  
Author(s):  
T Whyte ◽  
GA Williams

The crystal structure of tetraethylammonium bromopentacarbonyltungstate (0), [NEt4] [W(CO)5Br], has been determined by single-crystal X-ray diffraction methods at 22�1°C. Crystals are tetragonal, space group P4/n, with a 9.206(2), c 10.484(2) Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.034 for 820 independent reflections. The [W(CO)5Br]- anion possesses exact C4v symmetry, with bond lengths W-Br 2.736(1), W-COtrans 1.93(1) and W-COcis 2.034(6) Ǻ.


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