Methanol, crystal structure

B. Dreyfiis-Alain and R. Viallard. Compt, rend. 234, 536-8 (1952). Crystal structure methanol. 

Oxetane-2-methanol, t/ireo-a,3,3,4,4-pentamethyl-3,5-dinitrobenzoate X-ray crystal structure, 7, 365 Oxetane-3-methanol, 3-alkyl-reactions... 

Crystal structures of dinickel complexes with 0,0-bridging and 0,N-bridging (O-methylated) carbamate have been reported.2074,20 (874) produces one equivalent of ammonia upon heating in methanol/water solution.2082... 

The zinc complex of 1,1,1,5,5,5-hexafluoroacetylacetonate forms coordination polymers in reaction with either 2,5-bis(4-ethynylpyridyl)furan or l,2-bis(4-ethynylpyridyl)benzene. The X-ray crystal structures demonstrate an isotactic helical structure for the former and a syndio-tactic structure for the latter in the solid state. Low-temperature 1H and 19F NMR studies gave information on the solution structures of oligomers. Chiral polymers were prepared from L2Zn where L = 3-((trifluoromethyl)hydroxymethylene)-(+)-camphorate. Reaction with 2,5-bis(4-ethy-nylpyridyl)furan gave a linear zigzag structure and reaction with tris(4-pyridyl)methanol a homo-chiral helical polymer.479... 

The complex ds-[RhI(CO)(Ph2PCH2P(S)Ph2)] (9) is eight times more active than (1) for the carbonylation of methanol at 185 °C the X-ray crystal structure of the analogous complex with chloride in place of iodide was reported together with in situ spectroscopic evidence in the catalytic cycle.16 A more detailed study of (9) showed that indeed oxidative addition is faster, but that in this instance due to a steric effect the migratory insertion was also accelerated.17... 

The matter was settled in 1994 in back-to-back communications by Gould [12] and Dmitrienko [13]. Gould showed that treatment of natural prekinamycin with dirhodium tetraacetate in methanol yielded the fluorene 16 (Scheme 3.1). The vinyl proton formed in this reaction (H-l) provided a critical spectroscopic handle and allowed unambiguous determination of the carbocyclic structure, excluding the presence of an indole heterocycle. In parallel, his research group obtained a high-quality crystal structure of a kinamycin derivative. The refined data set was shown to best accommodate a diazo rather than cyanamide (or isonitrile) function. 

An extension of the research on silver complexes with Lewis base-functionalized mono(A-heterocyclic carbene) ligands has been made toward the better-studied and stronger coordinating phosphine systems. The reaction of a diphenylphosphine-functionalized imidazolium salt with silver oxide in dichloromethane affords a trinuclear silver carbene complex 50, as confirmed by electrospray-ionization mass spectrometry.96,97 Metathesis reaction of 50 in methanol using silver nitrate gives 51 in 33% yield. The crystal structures of 51 were found to be different when different solvents were used during crystallization (Scheme 12).97 One NO3- anion was found to be chelated to... 

Fe(Cp-C0NHCH2S03)2] anion have been identified (TTF)2[Fe(Cp-CONHCH2 S03)2] and the solvated (TTF)2[Fe(Cp-C0NHCH2S03)2]-2CH30H. Both crystal structures contain face-to-face dimers, with the main structural differences probably attributed to hydrogen bonding to the cocrystallized methanol. No physical properties of these salts have yet been published. 

Triorganoboron complexes of Af,0-heterocyclic carbenes are also known (36). Thus, triphenylboron-carbene complex 48 can be isolated from the reaction of methanol with an isocyanide adduct of BPh3 (47) in the presence of a catalytic amount of KF. The X-ray crystal structure of 48 demonstrated that the boron atom is tetrahedrally coordinated and that all four B-C bond distances are equal within experimental error. 

Manganese nitrosyl porphyrins [215] are considered good models for the iron-nitric oxide analogs, which are relatively unstable but very vital to many biological operations. A six-coordinate manganese nitrosyl porphyrin of the form (por)Mn(NO)(L), where por can be TTP (TTP = tetra(4-methylphenyl)porphine) and L = piperidine, methanol, 1-methyhmidazole, has been prepared [216] in moderate yields by the reductive nitrosylation of the (por)MnCl complex with NO in piperidine. The crystal structures of these compounds give indication of a linear Mn-NO bond [215]. 

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. 

A mechanistic study by Haynes et al. demonstrated that the same basic reaction cycle operates for rhodium-catalysed methanol carbonylation in both homogeneous and supported systems [59]. The catalytically active complex [Rh(CO)2l2] was supported on an ion exchange resin based on poly(4-vinylpyridine-co-styrene-co-divinylbenzene) in which the pendant pyridyl groups had been quaternised by reaction with Mel. Heterogenisation of the Rh(I) complex was achieved by reaction of the quaternised polymer with the dimer, [Rh(CO)2l]2 (Scheme 11). Infrared spectroscopy revealed i (CO) bands for the supported [Rh(CO)2l2] anions at frequencies very similar to those observed in solution spectra. The structure of the supported complex was confirmed by EXAFS measurements, which revealed a square planar geometry comparable to that found in solution and the solid state. The first X-ray crystal structures of salts of [Rh(CO)2l2]" were also reported in this study. 

Kinetic studies of the stoichiometric carbonylation of [Ir(CO)2l3Me] were conducted to model the rate-determining step of the catalytic cycle [73,85]. The reaction can form both fac,cis and mer,trans isomers of [Ir(CO)2l3 (COMe)] (Scheme 13), the product ratio varying with the solvent and temperature used. An X-ray crystal structure was obtained for the fac,cis isomer. Carbonylation of [Ir(CO)2l3Me] is rather slow and requires temperatures > 80 °C in chlorinated solvents (e.g. PhCl). However, the presence of protic solvents (e.g. methanol) has a dramatic accelerating effect. This is interpreted in terms of the protic solvent aiding iodide dissociation by solvation. 

The MM2 model resides very near the minimum 2 in the cellobiose energy map (cf. Fig. 9). (Among others, the crystal structure of methyl cellobioside-methanol complex is found in that minimum (15)). On the other hand, the PS79 model resides on the shallow saddle point between minima 2 and 3. 

The reaction of [TcOCU] with various monodentate aromatic thiols in methanol produces complexes of the general formula [TcO(SAr)4] (89), which can be precipitated with bulky cations. The X-ray crystal structure of the complex with Ar = mesityl has been elucidated and has square-pyramidal geometry, with the Tc atom displaced from the basal plane by about 0.846 Direct... 

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