Benzene-methanol solutions

As indicator electrodes glass and antimony electrodes are commonly used, but it must be noted that in benzene-methanol solutions, a glass-antimony electrode pair may be used in which the glass electrode functions as reference electrode. Glass electrodes should not be maintained in non-aqueous solvents for long periods, as the hydration layer of the glass bulb may be impaired and the electrode will then cease to function satisfactorily. 

Materials. PVCz (Takasago International Co. Ltd.) was purified by several reprecipitations froa benzene-methanol solution. 1-Ethylpyrene (EPy) was recrystallized and sublined in vacuo before use. PMMA was reprecipitated twice froa tetrahydrofuran solution with nethanol. PVCz films were prepared by spin-coating a 10 wtX anisole solution of the polyner on a quartz plate. PMMA and EPy were dissolved in chlorobenzene and cast on quartz or sapphire plates. 

A mixture of benzene and methanol (19 to 1) was used for spreading the alkyl phosphonates. To minimize the influence of benzene on the film properties, the concentrations of the spreading solutions were > 1.5 X 10 3 gram per ml., and the experiments were performed at tt > 4 dynes per cm. (25). Moreover, higher proportions of methanol in the spreading solution did not alter the film properties under study for selected monolayers. For the sulfates, a mixed solvent containing water-benzene-2-propanol (1 10 10) was used because with the benzene-methanol solutions the properties of the films depended on the age of solution from which the films were prepared. Stearic and palmitic acids were spread from either hexane or the benzene-methanol solvent used for the phosphonates. Identical desorption results were obtained with the two solvents. 

A benzene-methanol solution with Xch3oh = 0.5191 and ya i()( = 0.5571 has atotal vapor pressure of 292.5 torr. The vapor pressure of methanol is 150 torr and that of benzene is 210 torr at the temperature of the solution. Calculate the Raoult s law reference activity coefficients for benzene and methanol in this solution. 

Figure 4. Change of viscosity number of cis-atM tra.ns polybutadienes-l,4 in benzene-methanol solution (9 1) during visible light (Tungsten-SMW, Argaphoto-BM lampe. Philips) irradiation in the presence of air and dyes FL-Fluorescein, RB-Rose Bengale, MB-Meth-ylene blue. The concentration of dyes in solution was 10 or ICT M/I.

Irradiation of the paracyclophane (24) - in 1,2-dichloroethane solution in the presence of iodine - is reported to give an 80% yield of the novel quinolinophane-2(lH)-one (25) (Aly, Chapter 4). Tricyclic keto-indoles (27) are reported to be formed in good to excellent yields from the readily accessible enaminones (26) (Tietcheu et al. Chapter 4). The reaction occurs under various conditions, but the best results are obtained in the presence of sodium methoxide in benzene-methanol solution. 

The samples were synthesized by the same techniques as those used for the styrene ionomers (12). The protonated styrene-methacrylic acid copolymers were prepared by thermal initiation. The polymerization took place in sealed glass tubes in the bulk at 80 °C after several freeze-thaw cycles. A conversion of 10% was obtained after 19 hr. The polymer was precipitated in methanol and neutralized in a benzene-methanol solution. A similar procedure was used for the deuterated samples except that the unreacted deuterated styrene monomer was evaporated prior to the precipitation. The mixing of the deuterated and protonated styrene copolymers was performed in a benzene solution by stirring for 1 hr. The benzene used as the solvent contained a minimum amount of methanol necessary to dissolve the ionomer (approximately 5-10% for the samples of high ion content). The samples were freeze-dried, then dried further at 60°-80°C under vacuum, and finally compression-molded at Tg - - 30°C. 

Irradiation of the adduct (178) obtained from benzyne and a mesoionic thiazol-4-one in benzene-methanol solution resulted in extrusion of sulphur and formation of the isoquinolone (179).108 This is in complete contrast with the... 

It must be stressed that AG° values for 57 and 58 in the same solvent (e.g., MeOH or EtOH 95%) can differ by more than 1.5kJ/moI. Such differences seem to arise from different solvent effects on the two equilibria under scrutiny (despite the very similar structure of 57 and 58). This point of view is strongly supported by the fact that the relevant AH° and AS° values for 57 and 58 are also different. They are 5.19 0.23 kJ/mol and 10.6 + 0.7 J/mol/K for 57 and 5.71 0.12 kJ/mol and 13.8 0.4 J/mol/K for 58, respectively, in 6 4 (v/v) benzene-methanol solution (54). We also observed analogous differences between the equilibria in other derivatives of 1,3-dithianes (54, 98). Support for the hypothesis presented above comes from the work of Tschierske et al. (38), who showed that AG° values for dioxanes 59 and 60 (Scheme 21) differ... 

Tetrachloropalladate(II) ion catalyzes the interconversion of 1- and 2-butenes in aqueous solutions containing chloride and hydronium ions. Sodium tetrachloropalladate(II) catalyzes the conversion of allylbenzene to propenyl-benzene in acetic acid solutions. Tetrakis(ethylene))Lt,/x -dichlororhodium(l) catalyzes butene isomerization in methanolic hydrogen chloride solutions . Cyclooctadienes isomerize in benzene-methanol solutions of dichlorobis-(triphenylphosphine)platinum(11) and stannous chloride. Chloroplatinic acid-stannous chloride catalyzes the isomerization of pentenes. Coordination complexes of zero-valent nickel with tris(2-biphenylyl)phosphite or triphenyl-phosphine catalyze the isomerization of cis-1,2-divinylcyclobutane to a mixture of c/5,m-l, 5-cyclooctadiene and 4-vinylcyclohexene . Detailed discussions of reaction kinetics and mechanisms appear in the papers cited. 

Photolysis of poly(l,4-bis(dimethylsilyl)benzene) (4.98), [1050, 1552] poly(l,4-bis(dimethylsilyl)naphthalene (4.99) [1311], poly(2,5-bis(dimethyl-silyl)furan) (4.100) [986] and poly(2,5-bis(dimethylsilyl)thiophene) [1021] in benzene-methanol solution results in a rapid degradation of these polymers, according to the mechanism ... 

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