Phthalocyanine iron , reaction with

The reduced alkyl complexes are reoxidized by O2 to the iron(lll) alkyls. The corresponding diamagnetic phthalocyanine iron(ll) alkyl complexes, rFe(Pc)R), were prepared by two-electron reduction of Fe(Pc) by LiAIFl4 to give [Fe(Pc) (actually the Fe(I) phthalocyanine radical anion) followed by reaction with Mel, Etl or i-PrBr. The methyl compound, [Fe(Pc)CHi] was characterized by X-ray crystallography. ... 

We can now make sensible guesses as to the order of rate constant for water replacement from coordination complexes of the metals tabulated. (With the formation of fused rings these relationships may no longer apply. Consider, for example, the slow reactions of metal ions with porphyrine derivatives (20) or with tetrasulfonated phthalocyanine, where the rate determining step in the incorporation of metal ion is the dissociation of the pyrrole N-H bond (164).) The reason for many earlier (mostly qualitative) observations on the behavior of complex ions can now be understood. The relative reaction rates of cations with the anion of thenoyltrifluoroacetone (113) and metal-aqua water exchange data from NMR studies (69) are much as expected. The rapid exchange of CN " with Hg(CN)4 2 or Zn(CN)4-2 or the very slow Hg(CN)+, Hg+2 isotopic exchange can be understood, when the dissociative rate constants are estimated. Reactions of the type M+a + L b = ML+(a "b) can be justifiably assumed rapid in the proposed mechanisms for the redox reactions of iron(III) with iodide (47) or thiosulfate (93) ions or when copper(II) reacts with cyanide ions (9). Finally relations between kinetic and thermodynamic parameters are shown by a variety of complex ions since the dissociation rate constant dominates the thermodynamic stability constant of the complex (127). A recently observed linear relation between the rate constant for dissociation of nickel complexes with a variety of pyridine bases and the acidity constant of the base arises from the constancy of the formation rate constant for these complexes (87). 

The zeolite-encapsulated iron phthalocyanine catalyst was also active in this reaction, with an activity similar to that of the free complex. No decrease in catalytic activity was observed during the reaction, and after filtration the catalyst was reused in a new experiment without appreciable loss of catalytic activity (Fig. 4.). 

Iron(u), Rhodium(i), and Iridium(i).— Arguably iron(n) is square-planar in ferrous phthalocyanine in DMSO solution (c/. [PtClJ - in water ). The reaction of this compound with imidazole has been much studied, but kinetic ambiguities have prevented the unequivocal assignment of mechanism. Now the kinetic pattern for the analogous reactions with A-methylimidazole and with iV-n-butylimidazole, where there is no possibility of proton removal from nitrogen, has been shown to be very similar to that with imidazole. It is therefore now reasonable to rule out reaction of ferrous phthalocyanine with the deprotonated imidazole anion as a plausible pathway. ... 

Phthalocyanines are excellent lubricants at temperatures of 149—343°C (191). Combinations with other lubricants, like grease, molybdenum, or tungsten sulfides, have found appHcations in the automotive industry or professional drilling equipment (192—195). Further uses include indicators for iron(Il), molybdenum(V), and uranium(IV) (196) or redox reactions (197), medical appHcations like hemoglobin replacements (198) or sterilisation indicators (199), or uses like in gas filters for the removal of nitrogen oxides from cigarette smoke (200). 

In addition to nonheme iron complexes also heme systems are able to catalyze the oxidation of benzene. For example, porphyrin-like phthalocyanine structures were employed to benzene oxidation (see also alkane hydroxylation) [129], Mechanistic investigations of this t3 pe of reactions were carried out amongst others by Nam and coworkers resulting in similar conclusions like in the nonheme case [130], More recently, Sorokin reported a remarkable biological aromatic oxidation, which occurred via formation of benzene oxide and involves an NIH shift. Here, phenol is obtained with a TON of 11 at r.t. with 0.24 mol% of the catalyst. 

A practical method of modification of polysaccharides by clean oxidation using H2O2 as oxidant and cheap iron phthalocyanine as catalyst has been developed. Since no acids, bases or buffers and no chlorinated compounds were used, a pure product can be recovered without additional treatment. Importantly, this flexible method provides materials with a wide range of DScho and DScooh just by an appropriate choice of the reaction conditions. Oxidized polysaccharides thus obtained possess various, tailormade hydrophihc/hydrophobic properties which have been tested successfully in cosmetic and other apphcations. 

A mild aerobic palladium-catalyzed 1,4-diacetoxylation of conjugated dienes has been developed and is based on a multistep electron transfer46. The hydroquinone produced in each cycle of the palladium-catalyzed oxidation is reoxidized by air or molecular oxygen. The latter reoxidation requires a metal macrocycle as catalyst. In the aerobic process there are no side products formed except water, and the stoichiometry of the reaction is given in equation 19. Thus 1,3-cyclohexadiene is oxidized by molecular oxygen to diacetate 39 with the aid of the triple catalytic system Pd(II)—BQ—MLm where MLm is a metal macrocyclic complex such as cobalt tetraphenylporphyrin (Co(TPP)), cobalt salophen (Co(Salophen) or iron phthalocyanine (Fe(Pc)). The principle of this biomimetic aerobic oxidation is outlined in Scheme 8. 

Reaction of the manganese tropocoronand complex [Mn(tc-5,5)(NO)] with [Fe(tc-5,5)] results in complete transfer of the NO to the [Fe(tc-5,5)]. Other nitric oxide complexes appear in the sections on nitroprusside (Section S.4.2.2.6 above), on phthalocyanines (Section 5.4.3.7.4 above), and on polynuclear iron-sulfide complexes (Roussin s salts Section 5.4.5.9.2 below) Fe-por-phyrin-NO redox chemistry has been mentioned in Section 5.4.3.7.2 above. 

An electrocatalytic reaction is an electrode reaction sensitive to the properties of the electrode surface. An electrocatalyst participates in promoting or suppressing an electrode reaction or reaction path without itself being transformed. For example, oxygen reduction electrode kinetics are enhanced by some five orders of magnitude from iron to platinum in alkaline solutions or from bare carbon to carbon electrodes modified with Fe phthalocyanines or phenylporphyrins. For a comprehensive discussion of the subject, the reader is referred to refs. (76, 95, and 132-136). 

Convenient synthesis of chromium and iron phthalocyanines can be achieved by reaction of 1,2-dicyanobenzene with chromium hexacarbonyl or iron pentacarbonyl respectively in refluxing chloronaphthalene (equation 42).232... 

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