N-Butyronitrile

An oxoiron(V) species such as 6 derived from 1 and peroxides is accessible in nonaqueous media (51). The reaction of the tetraphenylphosphonium salt of la with 2 to 5 equivalents of m-chloroperbenzoic acid (mCPBA) at — 60°C in n-butyronitrile produces within about 10 s a bis-iron(IV)- i-oxo dimer followed by an as - yet uncharacterized EPR - silent iron(IV) intermediate. After 15 min, the deep green oxoiron(V) species 6 forms with distinct absorption maxima at 445 nm (e — 5400 Mr1 cm-1) and 630 nm (s — 4200 M-1 cm-1). At —60°C, 6 decays by 10% in 90 min, but it is stable for at least one month at 77 K. Selected spectral data for the oxoiron(V) species are shown in Fig. 13. DFT calculations favor the low-spin (S = 1/2) configuration of the ground state. The calculated Fe-0 bond length of 1.60 A is in excellent agreement with the EXAFS results. The Fe atom is displaced out of the 4-N plane by 0.5 A. 

Fig. 13. X band EPR (A) and Mossbauer (B) spectra of ca. 2mM 57Fe-enriched oxoiron(V) compound 6 in n-butyronitrile. EPR 28 K frequency, 9.66 GHz microwave power, 0.02 mW modulation, lmT. The dashed line is a spectral simulation. Mossbauer 140 K (A) and 4.2 K (B, C) in magnetic fields indicated incident y-beam perpendicular...

Vesey et al. 1976) and a series of commercially important, simple, aliphatic nitriles (e.g., acetonitrile, propionitrile, acrylonitrile, n-butyronitrile, maleonitrile, succinonitrile) (Willhite and Smith 1981) release cyanide upon metabolism. These drugs and industrial chemicals have been associated with human exposure to cyanide and have caused serious poisoning and, in some cases, death. 

Figure 5.21. Fluorescence spectra of PDS-Crown/CaI+ in (-------------) in CH3CN, (---------) n-butyronitrile...

DIHYDROFURAN DIVINYL ETHER METHACROLEIN 2-BUTYNE-1,4-DIOL ganna-BUTYROLACTONE cis-CROTONIC ACID trans-CROTONIC ACID METHACRYLIC ACID METHYL ACRYLATE VINYL ACETATE ACETIC ANHYDRIDE SUCCINIC ACID DIGLYCOLIC ACID MALIC ACID TARTARIC ACID n-BUTYRONITRILE ISOBUTYRONITRILE ACETONE CYANOHYDRIN... 

The key to the construction of the system is the choice of the quinone redox couple in the oil phase and the oil itself. The quinone compound must be reduced by Fe(II) ions, and the reduced form must be oxidized by bromine. These requirements indicate that the redox potential must be in the range between 0.77 and 1.07 V vs. NHE. After investigating of many redox compounds, we found that 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) dissolved in n-butyronitrile may be a good candidate for the system. DDQ has a largely positive redox potential because of its strong electron withdrawing substituents. 

Figure 17.11 shows the spectral changes of DDQ in an n-butyronitrile solution as the result of the redox reactions with Fe(II) and bromine in aqueous solutions. The spectra are for just the DDQ solution (A), and after successive contacts first with an aqueous solution of Fe(II) chloride (B) and then with an aqueous solution of bromine (C). When the DDQ solution was brought into contact with an Fe(II) solution, an absorption band appeared at 352 nm, completely agreeing with that of the reduced form (DDHQ) of DDQ. This absorption band decreased by bringing the solution into contact with a bromine solution, as shown in Fig. 17.11, The reproducible spectral changes indicate the applicability of DDQ as the mediator between the two photocatalytic reactions producing Fe(II) ions and bromine, respectively.

Fig. 17.12 Evolution of hydrogen from a double phase system. The aqueous solution (8.0 ml) contained 2 M potassium bromide and Ti02 powder (120 mg). The n-butyronitrile solution (1.7 ml) contained DDHQ (1.0 x 10-3 M). During the photocatalytic reaction, only the aqueous phase was photoirradiated. The inset shows the spectral change of the n-butyronitrile solution by photoirradiation for 1500 min, indicating that DDHQ was converted into DDQ.

Fig. 17.11 Spectral change of ar n-butyromtrile solution of DDQ as the result of successive reaox reactions with Fe(II) ions and bromine in aqueous solutions. A, DDQ (1.1 x 10-3 M) in n-butyronitrile(3.0 ml) B, the solution was kept in contact with an aqueous solution (5.0 ml) of Fe(II) chloride (2.8 x 10"2 I/) for 25 min C, the solution was kept in contact with an aqueous solution (8.0 ml) of bromine (1.3 x 10-3 M) and potassium bromide (0.5 M) for 30 min after the treatment with Fe(JI) ions. The spectra were obtained using a quartz cell with 1-cm path length.

Selection of the organic solvent for DDQ and DDHQ is also important. It must be a good solvent for DDQ and DDHQ, but it must not mix with water. Its chemical stability is also essential. To meet these requirements, we chose n-butyronitrile as the solvent. 

Fig. 2.25. Quenching effect on the short-wavelength FB fluorescence band of two different TICT state-forming compounds by adding traces of a polar solvent P to a nonpolar solution. Successive spectra correspond to repeated addition of small amounts of n-butyronitrile to initially 50 mL n-hexane solution, 5 x 10 6M/L. Note the strong difference in response observed for the two solutes.

The same group subsequently discovered that the loading of the chiral diamine catalyst can be reduced substantially if triethylamine is added in stoichiometric amounts as an achiral proton acceptor [37b]. As shown at the top of Scheme 13.23, as little as 0.5 mol% catalyst 45 was sufficient to achieve yields and ee comparable with the stoichiometric variant (application of the Oriyama catalysts 44 and 45 in the kinetic resolution of racemic secondary alcohols is discussed in Section 12.1). Oriyama et al. have also reported that 1,3-diols can efficiently be desymme-trized by use of catalysts 44 or 45. For best performance n-butyronitrile was used as solvent and 4-tert-butylbenzoyl chloride as acylating agent (Scheme 13.23, bottom) [38]. 

Nitriles are cyanogenic substances — substances that produce cyanide when metabolized. It is likely that nitriles are teratogens because of maternal production of cyanide in pregnant females. A study of the teratogenic effects on rats of saturated nitriles, including acetonitrile, propionitrile, and n-butyronitrile, and of unsaturated nitriles, including acrylonitrile, methacrylonitrile, allylnitrile, m-2-pcntenenitrile, and 2-chloroacrylonitrile, has shown a pattern of abnormal embryos similar to those observed from administration of inorganic cyanide.6... 

Butyl peroxylri methyl acetate, see Butyl peroxypivalate Butyl vinyl ether n-Butyraldehyde iso-Butyraldehyde n-Butyric acid iso-Butyric acid n-Butyric anhydride 2-Butyrolactone n-Butyronitrile Butyryl chloride Camphor Caproic acid... 

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