Acetonitrile, iron complex

Scheme 13 Template synthesis of [5.5.5J-P-N-N-P bis(acetonitrile) iron complexes (55-73)...

Iron, tris(hexafluoroacetylacetone)-structure, 1,65 Iron, tris(oxalato)-chemical actinometer, 1,409 photoreduction, 1,471 relief-image-forming systems, 6,125 Iron, tris(l,10-phenanthroline)-absorptiometry, 1,549 racemization, 1,466 solid state, 1,467 structure, 1, 64 lron(III) chloride amino acid formation prebiotic systems, 6,871 Iron complexes acetonitrile. 4,1210 acetylacetone, 2,371 amidines... 

Compound 79 reacts with 0(CH2)4 and NCMe in the presence of CFsSOsMe, like the iron complex 11 and the molybdenum and tungsten complexes 45 and 46, to give zwitterionic compounds [2-NO-2-PEt3-7-L-c/ow-2,l-CoCBioHio] [L = 0(CH2)4 (83), NCMe (84)]. Interestingly, the acetonitrile reaction gave in addition to 84 small amounts of the imine complex [7- N(Me) = C(H)Me -2-NO-2-PEt3-c/oio-2,l-CoCBioHio] (85), a product related to the iron and nickel compounds 34 and 78, respectively. The latter pair were the only products when 11 and 75, respectively, were... 

Removal of the 0-substituted Fp group can be achieved by conversion into the cationic alkene-Fp complex using Ph3CPF6 and subsequent treatment with iodide, bromide or acetonitrile. Oxidative cleavage with ceric ammonium nitrate in methanol provides the methyl esters via carbon monoxide insertion followed by demetallation. The [3 + 2]-cydoaddition has been successfully applied to the synthesis of hydroazulenes (Scheme 1.11) [34]. This remarkable reaction takes advantage of the specific nucleophilic and electrophilic properties of V-allyl-, cationic t 5-dienyl-, cationic ri2-alkene- and ti4-diene-iron complexes, respectively. 

We have thus been able to show that the acetonitrile-pentacarbonyl complexes M(CO)5NCMe (M = Cr, Mo, W) and cycloheptatriene-iron-tricarbonyl C7H3Fe(CO)3 are deprotonated as follows, without attack at the CO ligands (151). 

Fen(OPPh3)4+, Fen(bpy)2+, and Fen(MeCN)4+ in acetonitrile (MeCN) under an argon atmosphere. When dioxygen (02) (1 atm, 8.1 mM Em, —0.87 V vs. SCE in MeCN) is present, these iron complexes each exhibit a new irreversible reduction peak at potentials that are significantly less negative than those for the iron(II/I) couples and the 02/02 couple (Figure 9.8). 

However, in acetonitrile with the ratio PhS Fe 5 1, the mononuclear tetrahedral iron complex [Fe(SPh)4]2 is formed first, which reacts with sulfur to form the iron(III) dimer [Fe SPh),]2-according to equations (67) and (68). No further reaction takes place, but addition of methanol facilitates the reductive elimination of PhSSPh from the dimer to give the 2Fen2FenI cubane complex as in equation (69). Although this series of reactions has been written for PhS-, it appears similar reactions take place with alkyl as well as aryl thiolates. 

Thus, m-ClC6H4C(0)00H in acetonitrile will epoxidize alkenes without a catalyst, but the presence of an iron complex accelerates the process by several orders of magnitude. ... 

Using FeS04 (1.67 x 10 M) in conjunction with equimolar amounts of methyl-pyrazine-5-carboxylic acid N-oxide and trifluoroacetic acid, in a water-acetonitrile-benzene (5 5 1 v/v/v) biphasic system, with benzene-H202-FeS04 = 620 60 1, a benzene conversion of 8.6% is achieved (35 °C 4h). Hydrogen peroxide conversion is almost complete (95%) and selectivities to phenol are 97% (based on benzene) and 88% (based on H2O2) [13]. These values are definitely higher than those described in the literature for the classical Fenton system [14], whereas iron complexes with pyridine-2-carboxylic acid derivatives are reported to be completely ineffective in the oxidation of benzene under the well-knovm Gif reaction conditions [15]. 

Various chiral and achiral derivatives of the fra 5-acetonitrile bis(iminophosphine) [6.5.6]-P-N-N-P iron complexes can be synthesized by a one-pot condensation/ template reaction involving [FeCH OlglfBF ], 3 (2 equiv.), and a diamine (26-28) to yield complexes (29-31) (Scheme 9). These new compounds were tested for catalytic activity in the DH of acetophenone to 1-phenylethanol. Low to moderate conversions were observed in most cases at room temperature and 25 atm H pressure, with precatalyst 29 being able to achieve up to 95% conversion at 50 °C in 18 h. Only complex (R,R)-31 was enantioselective [ee of 61% (5)], but with poor conversion (4%) at elevated temperatures. 

When the phosphonium dimers were reacted with base in the presence of Fe ", there was evidence for the formation of new intermediate iron complexes, which were characterized as bis-tridentate iron complexes when using smaller PR groups (R = Et, Ph) on phosphorus (Scheme 12). These complexes were isolated as the BPh salts after salt exchange of BF and FeBr - by the addition of NaBPh. When these kinetic products were left in refluxing acetonitrile for several days, the desired tetradentate complexes were formed. " ... 

NC2H3, Acetonitrile, iridium complex, 21 104 -----, iron complexes, 21 39-46... 

S.-F. Li, H.A. Mottola, Continuous flow determination of relative diffusion coefficients of iron complexes with ligands of the 1,10-phenanthroline family and with 3-(2-pyridyl)-5,6-diphenyl-l,2,4-triazine in acetonitrile-water solutions, Anal. Chim. Acta 289 (1994) 79. 

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