The GX crystallographic program system

Section: Commentmentioning

confidence: 99%

Structure of N1-(3-phenoxypropyl)-4,7-diaza-1-azoniatricyclo[5.2.1.04,10]decane bromide hydrate

Farrugia¹,

Lovatt²,

Peacock³

1993

“…Cell refinement: CAD-4 Express. Data reduction: GX (Mallinson & Muir, 1985). Program(s) used to solve structure: SHELXS86 (Sheldrick, 1985).…”

Section: Methodsmentioning

confidence: 99%

cis-(Benzenethiolato)bis(tert-butyl isocyanide)carbonyl(cyclopentadienyl)molybdenum(II), [Mo(C6H5S)(C5H9N)2(C5H5)(CO)]

McDermott¹,

Muir²,

Pétillon³

et al. 1996

Self Cite

75al., 1995), we obtained the mononuclear isocyanide complexes [CpMo(SPh)(CO)(CNR)2]: (1) R = tBu and (2) R = xylyl. At 293 K, solutions of both (1) and (2) contain two isomeric species. Thus, the 13C NMR spectra show two signals of differing intensity for the CO and Cp ligands; the latter also displays two 1H signals. For the CNR groups two patterns are also observed, one consisting of two signals of equal intensity, the other of a single signal. These results can be explained if solutions of (1) and (2) contain a mixture of cis and trans geometric isomers. The two isomers do not appear to interconvert readily between 293 and 353 K in solution. Although their relative abundances are different in different solvents, the cis form is always the major component. Only a single isomer of (1) could be obtained as a crystalline solid; when this solid was dissolved in toluene-d8 at 210 K, the IH NMR spectrum at 210 K of the resulting solution indicated the presence of only the cis isomer. ,H°To confirm this spectroscopic interpretation we have determined the structure of (1) by X-ray analysis (Fig. 1). As expected, the complex is a mononuclear 18-electron MoII species. The metal atom adopts four-legged piano-stool coordination with cis isocyanide groups. Similar metal coordination occurs in the recently described complex [CpW(CO)2(p-S-C6Hn-CH3)(CNtBu)] (Shaver, Hynes & Trojansek, 1994) which, like (1), exists as a mixture of isomers in solution; however, only the trans isomer of this tungsten compound could be obtained as a crystalline solid.The Mo--S bond length in (1) The Mo---CNtBu bond lengths differ by 0.033 (6)A, the longer bond being trans to CO. This may reflect the greater trans influence of the 7r-acid CO compared with that of thiolate. The longest Mo--C(Cp) bond (to C31) is that most nearly trans to CO (see Fig. 1). There are previous suggestions that trans influence may be an explanation of bond-length trends in Mo piano-stool complexes (e.g. see Creswick & Bernal, 1982). Other structural features of (1) ExperimentalReactions were performed under argon using standard Schlenk techniques and solvents were deoxygenated and dried by standard methods. [Cp2Mo2(#-H)(#-SPh)(CO)4] (200 mg, 0.37 mmol) was dissolved in 30 ml of toluene together with 3 equivalents of isocyanide (1.1 mmol) and irradiated with UV light for 2 h. The solution changed from red to orange during this time. The solvent was removed under vacuum. The residue was then dissolved in the minimum amount of dichloromethane and chromatographed on a silica gel column. Elution with dichloromethane:tetrahydrofuran (100:1) gave an orange 76 [Mo(C6 H5 S)(C5 H9 N)2 (C5 H5 ) (CO)] band of (1) which was washed with pentane. Recrystallization N2 from diethyl ether gave (1) lamp placed approximately 10 cm from a Pyrex vessel. Spec-c42 troscopic data for (1) and (2) have been deposited.Crystal data (,4, °) Cp is the centroid of the cyclopentadienyl ring C31-C35. Data collection: CAD-4 Express (Enraf-Nonius, 1992). Cell refinement: CAD-4 Express. Data red...

“…Yellow prisms from toluene solution" crystal dimensions ca 0.3 × 0.4 x 0.3 mm; EnrafNonius CAD-4F diffractometer; graphite monochromator; 0/20 scan mode; cell parameters refined by least-squares method on basis of 25 independent 0 values, 11 _< 0 < 13°; intensities measured to 0 = 25 ° over range of hkl 0 to 13, -17 to +17, -21 to +21; 363, 327, 626 measured every 2h, linear decay correction applied corresponding to 8% decay over 169 h data collection, 10 643 reflections measured, 10 008 independent data with 7123 having I > 3.0a(/) considered observed and used in structure determination and refinement; Rin t 0.028 before and 0.027 after absorption correction; corrected for Lorentz/polarization, absorption (DIFABS; Stuart & Walker, 1983); 0108-2701/88/071307-03503.00 range of transmission factors on F, 0.823 to 1.238; solved by direct methods (MITHRIL; Gilmore, 1984) and subsequent full-matrix least squares; anisotropic thermal parameters for non-H atoms; H atoms included at fixed calculated positions [cyclohexyl C-H= 1.0A: hydrides (HYDEX; Orpen, 1980) Crystallography (1974); calculations carried out on a Gould-SEL 32/27 minicomputer using the GX suite of programs (Mallinson & Muir, 1985). Final positional parameters are given in Table 1, with selected bond distances and angles in Table 2.…”

Section: Abstract [Os3pt(j/-h)2(co)i0{p(c6hii)3}2mentioning

confidence: 99%

Structure of 1,2,2,2,3,3,3,4,4,4-decacarbonyl-1,2;3,4-di-μ-hydrido-1,3-bis(tricyclohexylphosphine)-cyclo-platinumtriosmium(2 Pt–Os)(3 Os–Os)–toluene (1/1)

Farrugia¹

1988