Acetone crystal structure

The most extensively investigated HNL structures are those from H. brasiliensis (HbHNL)" " and M. esculenta (MeHNL)," which are highly homologous (76% identity). For MeHNL, the crystal structure of the wild-type enzyme complexed with acetone has been reported in 2001 (Fig. 1)." ... 

Both enzymes belong to the family of a,p-hydrolases." The active site of MeHNL is located inside the protein and connected to the outside through a small channel, which is covered by the bulky amino acid tryptophane 128." It was possible to obtain the crystal structure of the complex with the natural substrate acetone cyanohydrin with the mutant SerSOAla of MeHNL. This complex allowed the determination of the mode of substrate binding in the active site." A summary of 3D structures of known HNLs was published recently." " ... 

Jones, P.G. (1992) [(Methyldiphenylphosphonio)methanide] tris(pentafluorophenyl)gold(III) acetone solvate. Acta Cr/staUographica, Section C Crystal Structure Communications, C48(7), 1209-1211. 

The complex [Co(NH3)5(OS02CF3)]2+ undergoes triflate substitution by cyanate and condensation with acetone to form the unusual bis-bidentate imine complex (213)917 in a reaction reminiscent of the classic Curtis condensation of acetone with ethylenediamine. Apart from the novelty of the synthesis, the reported crystal structure was only the second of a CoN6 complex bearing a cyanate ligand. 

Five-coordinate Ni111 complexes (89) have been prepared by oxidation of the square planar Ni11 precursor complexes [Ni(L)X] with either X2 or CuX2, and the crystal structure of the iodo derivative has been determined. The geometry at Ni is best described as square pyramidal, with the Ni atom displaced approximately 0.34 A out of the basal plane towards the apical I atom. EPR confirms the Ni111 oxidation state, in which the unpaired electron of the low-spin d1 system is situated in the dz2 orbital.308,309 In aqueous solution full dissociation of both X anions occurs, while in acetone solution dissociation is not significant. The redox couple [Nin NCN (H20)]+/ [Ni111 NCN (H20)ra]2+ in water is +0.14V (vs. SCE). 

In 1979 the bieyclic diol exo-2,ejco-6-dihydroxy-2,6-dimethylbicyclo[3.3.1]nonane (i) was prepared and observed to co-crystallise with various solvents, including ethyl acetate, chloroform, toluene, dioxane, and acetone. A crystal structure determination of the ethyl acetate compound revealed the occurrence of a helical canal host structure, containing ethyl acetate as guest (with 3 1 diol ethyl acetate stoichiometry), and that spontaneous resolution had occurred on crystallisation of the multimolecular inclusion compound 6>. 

With the long alkyl chain substitutions on the A-heterocyclic carbenes, lamella-structured silver(i) carbene complexes 27a and 27b (Figure 14) were isolated.74 It is interesting to note that the synthetic procedures for the two complexes are the same except for the use of different solvents of crystallization. The dinuclear 27a was obtained from recrystallization in dichloromethane- -hexane while the tetranuclear 27b was obtained from acetone. The structure of 27a could be interpreted as the dimeric form of [Ag(carbene)Br] bridged by intermolecular Ag-Br interactions. The Ag-G bond has a distance of 2.094(5) A. The tetranuclear 27b, on the other hand, could be regarded as two monocationic bis(carbene)silver(i) bridged by an [Ag2Br4]2 anion, with the presence of short Ag(cationic)-Ag(anionic) contact (3.0038(18) A) and comparable Ag-G bond distances (2.0945(5), 2.138(13) A). A related... 

UV absorption maxima occur at 236, 274 and 316 nm. The molecular formula of zearalenone is C18H22Os, its molecular weight is 318.4 g/mol and its melting point is 162-163°C (Blackwell et al. 1985 Josephs et al. 2003). The maximum fluorescence in ethanol occurs with irradiation at 314 nm and with emission at 450 nm. Its solubility in water is about 0.002 g/100 ml. In an aqueous solution of inositol, the presence of zearalenone can change the crystal structure of this alcohol, which indicates the possibility of interaction between both substances (our observations). Moreover, zearalenone is slightly soluble in hexane and progressively more so in benzene, acetonitrile, methylene chloride, methanol, ethanol and acetone. However, it is readily soluble in aqueous alkali. 

Antibodies produced by this procedure were screened for their ability to react with the hapten to form the vinylogous amide 6, which has a convenient UV chromophore near 318nm, clear of the main protein absorption. Two antibodies selected in this way catalysed the expected aldol reaction of acetone with aldehyde 7 by way of the enamine 8 (Scheme 3) the remainder did not. These two effective aldolase mimics have been studied in some detail, and a crystal structure is available for (a Fab fragment of) one of them.126,281... 

The preparation and characterization of several octahedral Ru(II) complexes containing s-trans coordinated dienes have been reported. The Zn mediated reduction of Ru(acac)3 in the presence of a 1,3-diene affords (diene)Ru(acac)2 complexes as a mixture of diastereo-mers (eg. 129)13a b. Reaction of [(trispyrazolylborate)RuCl]jt or [(NH3)4Ru(acetone)2]2+ [CIO4 ]2 with acyclic dienes yields complex 130 or cation 131 respectively130,14. Coordination of the ligand as an s-trans diene was indicated either by crystal structure or by determining C2v symmetry on the basis of NMR spectroscopy. 

The other change that needed to be made in the synthesis of RSR 13 for in vivo administration was the method of purification. RSR 13 is used in vivo as the sodium salt. I prepared the first batch for in vivo toxicology by triturating RSR 13 sodium salt with acetone to remove any vestiges of water. However, the first industrial scale-up procedure called for crystallization of the salt from ethanol-water. The ethanol-water crystals were not as soluble as the acetone triturated method and could not be formulated at a reasonable volume. We performed the crystal structure determination of the ethanol-water crystals and found that it was a heptahydrate (Figure 17.5) [50]. The problem for large-scale production of RS R13 was solved eventually by the industrial producers of RSR 13. 

Isoxazoline derivatives of Cgo such as 250 (Scheme 4.40) are accessible by 1,3-dipolar cycloadditions of nitrile oxides to [6,6] double bonds of the fullerene [2, 278, 291-305]. The nitrile oxides 249 with R = methyl, ethyl, ethoxycarbonyl and anthryl are generated in situ from the corresponding nitroalkane, phenyl isocyanate and triethylamine. The isoxazoline derivative of Cgo 250 (with R = anthryl) crystallizes in black prisms out of a solvent mixture of CS2 and acetone (3 2) [292]. X-ray crystal structure analysis shows that addition of the nitrile oxide occurs on a [6,6] double bond of the fullerene framework. 

A crystal structure of an unstable JV,JV -[bis-(d-tosylbenzyl)urea-acetone hydrogen-bonded adduct had been reported earlier Tel, R M. and Engberts, J.B.F.N. (1976)./. Chem. Soc. Perkin Trans. 2, 483 88. 

RUj(0H)Cl(H20) (napy)2](C10 ) (napy=l, 8-naphthyridine) is made from Ru3(napy)2Cl and AgClO in acetone [794,795], The X-ray crystal structure shows the two Ru atoms to be bridged by the chloro and hydroxo ligands, with two bridging naphthyridine ligands (Fig. 1.35). 

Reaction of (-)-a-pinene (1) with stoich. RuO /CCl gave a ketoaldehyde (2), probably via a Ru(VI) diester (4). If the reaction is performed using RuO in acetone rather than CCl, the a-ketol (3) is the main product. It is likely that a Ru(VI) diester (4) is involved such a species was isolated and both H and NMR data suggest the structure shown in (Fig. 3.8). An X-ray crystal structure determination was carried out on the osmium analogue of (4) [178]. 

Tetraethylammonium pentachloroindate(lll) is a white crystalline solid, mp 285° (dec.), slightly soluble in ethanol at 20° (more so at the boiling point) and also soluble in acetone and dichloromethane. The IR7,8 spectrum shows absorptions at 294 (s), 282 (s), 268 (s), 152 (sh), and 142 cm 1 Raman emissions have been reported9,10 at 294 (s), 287 (sh), 194 (w), 167 (m), 123 (m), and 106 (m) cm"1. The crystal structure determination11,12 shows that the anion is essentially square-based pyramidal, an unusual stereochemistry for main group elements MX5 species. 

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