Spectroscopic and crystallographic studies of phosphino adducts of gallium(III) iodide

1997 ◽  
Vol 75 (3) ◽  
pp. 333-341 ◽  
Author(s):  
Martyn A. Brown ◽  
Jesus A. Castro ◽  
Dennis G. Tuck

The solid state structures of the compounds GaI3•PPh3 and Ga2I6•dppe ( dppe = 1,2-bis(diphenylphosphino)ethane ) have been determined. For the former, in which the GaI3P core has C3v symmetry, the structure is trigonal, with a = 14.961(2) Å, c = 16.509(3) Å, V = 3199.5(4) Å3, Z = 6, space group [Formula: see text]. In Ga2I6•dppe, the ligand bridges two GaI3P centres; the structure is monoclinic, a = 10.196(7) Å, b = 15.363(1) Å, c = 23.027(9) Å, β = 98.735(4)°, V = 3565.1(3.2) Å3Z = 4, space group P21/n The use of 31P NMR spectroscopy shows that GaI3•PPh3 is slightly dissociated in nonaqueous solution, and the effect of adding Ph3P or I− has been investigated. Similar studies with Ga2I6•dppe are also reported. In each system, four-coordination at gallium is dominant; an equally important factor is the dimerization of uncomplexed GaI3 to Ga2I6 in these solutions. Keywords: gallium(III) iodide, complexes, phosphorus, NMR, crystallography.

2016 ◽  
Vol 52 (45) ◽  
pp. 7186-7204 ◽  
Author(s):  
Sharon E. Ashbrook ◽  
David McKay

DFT calculations are an important tool in assigning and interpreting NMR spectra of solids: we discuss recent developments and their future potential in the context of NMR crystallography.


1992 ◽  
Vol 70 (3) ◽  
pp. 919-925 ◽  
Author(s):  
A. Wallace Cordes ◽  
Charles M. Chamchoumis ◽  
Robin G. Hicks ◽  
Richard T. Oakley ◽  
Kelly M. Young ◽  
...  

The preparation and solid state characterization of the bifunctional radical furan-2,5-bis(1,2,3,5-dithiadiazolyl) 2,5-[(S2N2C)OC4H2(CN2S2)] and the related monofunctional radical 2-cyanofuran-5-(1,2,3,5-dithiadiazolyl) 2,5-[(S2N2C)OC4H2(CN)] are described. The crystal structure of 2,5-[(S2N2C)OC4H2(CN2S2)] is orthorhombic, space group Pna21, and consists of interleaved arrays of dimers, for which the mean interannular [Formula: see text] contact is 3.137 Å. The crystal structure of the monofunctional radical 2,5-[(S2N2C)OC4H2(CN)] is monoclinic, space group P21/n, and consists of a ribbon-like network of dimers (mean interannular [Formula: see text] interconnected by close head-to-tail [Formula: see text] contacts. The dimer units form stacks parallel to z, with a mean interdimer [Formula: see text] separation of 3.956 Å. The similarities and differences between these two crystal structures and those of related benzene-substituted systems are discussed. Keywords: dithiadiazolyl radicals, furan-based diradicals, cyanofuran-based radicals, radical dimers, crystal structures.


1997 ◽  
Vol 52 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Christian Meyer ◽  
Dietrich Mootz ◽  
Birgit Bäck ◽  
Rolf Minkwitz

The solid-state structures of the low-melting compounds bis(trifluoromethyl)disulfane (CF3SSCF3, triclinic, space group P 1̄, Z = 2) and bis(trifluoromethyl)trisulfane (CF3SSSCF3, monoclinic, space group C2/c, Z = 4) have been determined on single crystals with MoK α radiation at -160°C. The trisulfane has trans conformation. The geometry of both molecules agrees well with results of electron diffraction on the gaseous state. A comparison is made also with the crystal structures of the related molecules CF3TeTeCF3 and CF3OOOCF3


2007 ◽  
Vol 80 (9) ◽  
pp. 1776-1779 ◽  
Author(s):  
Satoshi Takara ◽  
Andrei S. Batsanov ◽  
Douglas J. Schaffer ◽  
Michael Takase ◽  
Janice A. Kunishige ◽  
...  

2001 ◽  
Vol 79 (5-6) ◽  
pp. 607-612 ◽  
Author(s):  
Man-Kit Lau ◽  
Joyce LC Chim ◽  
Wing-Tak Wong ◽  
Ian D Williams ◽  
Wa-Hung Leung

Reaction of [OsO4] with C7H7MgBr (C7H7 = 2-methylphenyl) followed by column chromatography afforded the reported osmium tetraaryl [Os(C7H7)4] along with the oxo-osmium(VI) ([OsO(C7H7)4]) (1) (13%) and the dioxo-osmium(VI) ([OsO2(C7H7)2]) (2) (25%) complexes. Treatment of [OsO4] with C8H9MgBr (C8H9 = 2,5-dimethylphenyl) gave a mixture of [Os(C8H9)4] (3) (34%) and [OsO(C8H9)4] (4) (4%) while that with C8H9OMgBr (C8H9O = 4-methoxy-2-methylphenyl) afforded [OsO(C8H9O)4] (5) in 20% yield. Oxidation of 3 with 3-chloroperoxybenzoic acid afforded 4 in good yield. The solid-state structures of 1 and 4 have been established by X-ray crystallography. Crystals of 1 are tetragonal with a = 13.080(1) and c = 6.6506(5) Å, V = 1137.9(1) Å3, Z = 2, and space group of P4/n; while those of 4 are tetragonal with a = 13.593(2) and c = 7.377(2) Å, V = 1363.0(5) Å3, Z = 4, and space group of P4/n. The geometry around osmium in both complexes is square pyramidal with the oxo ligand occupying apical position. The Os—O and Os—C distances in 1 are 1.652(2) and 2.084(1) Å, respectively, while those in 4 are 1.688(7) and 2.088(4) Å, respectively. The cyclic voltammograms of the monooxo aryl osmium(VI) compounds show reversible Os(VI/V) couple at around –1.4 V vs. ferrocene/ferrocenium couple.Key words: osmium(VI), oxo aryl complexes.


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