Nitrosyl nitro

The reaction suggests the possible employment of the nitrosyl nitro conversion for oxide ion acceptance and donation, and this in turn could play a role in the future development of nitrosyl complexes as oxygenation agents. 

N NMR spectroscopy was used to characterize the complex that was initially believed to be [RhCl(NO)2(PR3)2] R = Cy, Pr (113) and discussed in Section III,C in connection with crystallographic disorder problems. The N NMR resonances of both derivatives have very similar chemical shifts to those found for [RhCl(N02)(N0)(PPh3)2] (Table VII), which demonstrates that the complexes obtained by reaction of NO(g) with [RhCl(S02)(PR3)2] R = Pr, Cy are correctly formulated as nitrosyl-nitro compounds. 

A variety of other complexes react with nitric oxide to give oxygen transfer products. The reaction of [RhCl(PPh3)3] with NO, free from NO2, gives N2O and the nitrosyl nitro compounds [RhCl-(N02)(N0)(PPh3)2] 69), and low-valent carbonyl compounds yield an array of nitrosyl-nitrite polymers and oligomers on reaction with nitric... 

Scheme 6 The nitrosyl-nitro redox couple in homogeneous oxidation catalysis...

Ru(terpy)(NH3)2NO], no kinetic evidence for the subsequent electron-transfer reaction was observed. However, some experimental data (95) indicate that such electron transfer does occur, but its rate is very similar to the rate of the third reaction step so that they could not be separated kinet-icaUy. The reason for this reactivity behavior is that NO located in the in-plane position of the trans isomer favors a rapid, not kinetically observable electron transfer that does not require a process induced by the binding of additional NO. Notably, in the case of the trans isomer, a slow nitrosyl—nitro interconversion as second reaction step succeeding electron transfer was observed, most probably as a result of the high degree of positive charge on coordinated NO in this isomer (see Scheme 10) (95). 

A -Steroids react sluggishly with nitrosyl fluoride to yield after alumina chromatography the nitro-olefin (44) (14 %), and 0.7 % of the 2a-fluoro ketone (45), the former probably arising by alumina-catalyzed dehydrofiuorination of an intermediate 2-fluoro-3-nitro adduct. 

The double bond of a, -unsaturated ketones reacts with nitrosyl fluoride but only at room temperature and in small yield. Cholestenone produces a 4.2% yield of a 4< -fluoro-5( -nitro-3-ketone (46) after alumina chromatography. Similarly, the A -20-ketone grouping in 3j5-acetoxypregna-5,16-dien-20-one (47) reacts to form after chromatography a 14% yield of the... 

Mechanism The reaction of and A -steroids with nitrosyl fluoride to form ni trimines is best discussed in conjunction with the nitrosyl chloride reaction leading tothe5a-chloro-6 -nitro steroids (33). Since nitroso alkanes are oxidized with nitrosyl chloride to nitro alkanes it is believed that 5a-chloro-6j5-nitro steroids are formed in this way from an initially formed 5a-chloro-6 -nitroso adduct. The same is true for nitrosyl fluoride up to the stage of the nitroso fluoride (56). Since NOF is a weaker oxidizing agent than NOCl the nitroso fluoride tautomerizes to the fluoro oxime (57) at a rate... 

Equations 1-10 illustrate some mild methods that can be used to cleave amides. Equations 1 and 2 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B12. Butyl nitrite, nitrosyl chloride, and nitrosonium tetrafluoroborate (NO BF4 ) have also been used to cleave amides. Since only tertiary amides are cleaved by potassium -butoxide (eq. 3), this method can be used to effect selective cleavage of tertiary amides in the presence of primary or secondary amides.(Esters, however, are cleaved by similar conditions.) Photolytic cleavage of nitro amides (eq. 4) is discussed in a review. 

Nitrosylsulfuric Acid (Nitroso, Nitrosyl Sulfate, Nitrosulfuric Acid, Nitroxylsulfuric Acid, Nitro-sulfonic Acid, Nitrosyl Hydrogen Sulfate, Nitro Acid Sulfite). HNOs S, NO HS03, HNOS04, ONOSO3H, mw 127.08, N 11.02%, colorl prisms mp, decomps 73.5°. In moist air the crysts decomp with the formation of sulfuric and nitric... 

A novel, mild system for the direct nitration of calixarenes has been developed using potassium nitrate and aluminum chloride at low temperature. The side products of decomposition formed under conventional conditions are not observed in this system, and the p-nitro-calixarenes are isolated in 75-89% yields.17 Such Friedel-Crafts-type nitration using nitryl chloride and aluminum chloride affords a convenient system for aromatic nitration.18 Nitryl chloride was previously prepared either by the oxidation of nitrosyl chloride or by the reaction of chlorosulfonic acid with nitric acid. However, these procedures are inconvenient and dangerous. Recently, a mixture of sodium nitrate and trimethysilyl chloride (TMSC1) has been developed as a convenient method for the in situ generation of nitryl chloride (Eq. 2.6). 

The specific solvation of NO coordinated to Fe(III) and the resulting solvent reorganization upon NO dissociation (Fig. 3) finds some analogy with the nitrophorins, which are heme protein systems for NO transfer found in certain blood sucking insects. The crystal structure of one nitro-phorin, NP4, shows that binding of NO to the Fe(III) center leads to a collapse of the protein around the coordinated NO. The distal hemebinding pocket in nitrophorin NP4 is quite open to solvent in the absence of NO. It was postulated that collapse of the protein around the heme nitrosyl led to increased retention of bound NO at low pH (25). 

Al-Nitrosodiethanolamine, 2 449, 450 Nitroso dyes, 9 263-264 Nitro soluble dyes, 7 373t Nitroso soluble dyes, 7 373t Nitrosomonas, use in recirculating aquaculture biofiltration, 3 196 P-Nitrostyrenes, preparation by nitration of styrenes, 16 581 Nitrosyl chloride, 20 634 Nitrosyl complexes, osmium, 19 642 Nitrosyl perchlorate, 18 279 Nitrosyl tetrafluoroborate, 4 144t n-Nitrotoluene, 17 263... 

Methyl 3,3-diazido-2-cyanoacrylate, 1824 Methylenebis(3 -nitramino-4-methylfurazan), 2805 1-Methyl-1,2,3-triazole, 1189 Nitrosyl azide, 4766 3-Nitro-l,2,4-triazolone, 0716 Pentazole, 4443... 

Beynon, J.H. Bertrand, M. Cooks, R.G. Metastable Loss of Nitrosyl Radical From Aromatic Nitro Compounds. J. Am. Chem. Soc. 1973,95, 1739-1745. 

The Fe(II)-NO complexes of porphyrins 66-68) and heme proteins 24, 49, 53, 69-76) have been studied in detail by EPR spectroscopy, which allows facile differentiation between five-coordinate heme—NO and six-coordinate heme—NO(L) centers. However, only a few reports of the Mossbauer spectra of such complexes have been published 68, 77-82), and the only Fe(III)-NO species that have been studied by Mossbauer spectroscopy include the isoelectronic nitroprusside ion, [FeCCNlsCNO)] (7S), the five-coordinate complexes [TPPFe(NO)]+ 68) and [OEPFe(NO)]+ 82), and two reports of the nitro, nitrosyl complexes of iron(III) tetraphenylporphjrrins, where the ligand L is NO2 82, 83). 

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