Iron 2,4-pentanedionate

Examples of the components of the gelling composition are a water-soluble polymer such as polyacrylamide, an iron compound such as ferric acetyl-acetonate or ammonium ferric oxalate, and a ketone such as 2,4-pentanedione [1247]. The composition forms a temporary gel that is useful for the temporary plugging of a formation. The temporary gels that are formed will disappear after 6 months. 

Figure 1 Transfer chemical potentials for selected iron complexes from water into aqueous methanol (on the molar scale, at 298 K). Ligand abbreviations not appearing in the list at the end of this chapter are acac = acetylacetonate (2,4-pentanedionate) dmpp = l,2-dimethyl-3-hydroxy-4-pyridinonate, the anion from (24) malt = maltolate (2-methyl-3-hydroxy-4-pyranonate, the anion from (233)).

The organometallic chemistry of the first-row transition metals generally starts with the binary metal carbonyl organometallic complexes. Noncarbonyl organometallic complexes starting with other easily accessible binary compounds provide entries to a broader spectrum of complexes. In this context, we describe the synthesis of the mixed sandwich complex (tj5-pentamethylcyclopentadienyl) ( j5-cyclopentadienyl) iron as an example of the synthetic utility of the solution-stable derivative (>j5-pentamethyl-cyclopentadienyl) (2,4-pentanedionate) iron. 

More examples of the usefulness of the ( j5-pentamethylcyclopentadienyl) (2,4-pentanedionate) iron as a source of the (>j5-pentamethylcyclopenta-dienyl) iron fragment can be found in several references 4-9... 

Iron(II) bis(acetylacetonate) has been prepared by reaction of iron(II) sulfate in aqueous solution with 2,4-pentanedione in the presence of bases such as pyridine and ammonia1 and by reaction of iron (II) chloride tetrahydrate in aqueous solution with the stoichiometric amounts of 2,4-pentanedione and piperidine.2 Neither publication reports yields and the lack of complete experimental details makes duplication difficult. The following procedure is a modification of that reported by Buckingham et al.2 and employs either anhydrous iron(II) chloride or the corresponding adduct with THF. The reaction is carried out in diethyl ether as solvent instead of water. 

Cyclization of trienes.1 In combination with 2,2-bipyridyl (bpy), an iron(O) species prepared by reduction of iron(III) 2,4-pentanedionate with A1(C2H5)3 (3 equiv.) promotes cyclization of trienes (1) in which a 1,3-diene unit is tethered to an ally lie or homoallylic ether group. vic-Disubstituted cyclopentanes or cyclohexanes are formed, and the cisltrans disposition of the substituents is controlled by the geometry of the allylic double bond. Thus (Z,E-)1 is cyclized to trans-2, whereas (E,E)-1 is cyclized to cis-2. 

The reaction, of metal carbonyls with 1,3-diketones generally results in a complete displacement of carbon monoxide accompanied by oxidation of the metal to yield 1,3-diketonato complexes. For example, iron pentacarbonyl, chromium hexa-carbonyl, and molybdenum hexacarbonyl afford FefCgHjOOs,1 Cr(CsHr02)8,2 and Mo(CgH702)s,2,s respectively, when allowed to react with 2,4-pentanedione. 

When a metal ion such as nickel (II) is absent, thiazoles and mercaptals are formed. Such reactions have been carried out in which the diketone was biacetyl, 2,3-pentanedione, 2,3-octanedione, l-phenyl-l,2-propane-dione, and 1,2-cyclohexanedione (51). In like manner, the tris complexes of W,W -dimethyl-2,3-butane diimine with iron(II), cobalt(II), and nickel(II) may be prepared from methylamine and biacetyl when the appropriate metal ion (27j 28j 41) is present. Replacing methylamine with hydroxylamine causes the formation of a-dioximes (13). 

With dipivaloylmethane, the zinc(II), cobalt(II) (12), and iron(II) complexes (19) are all isomorphous. A three-dimensional x-ray structural determination (12) of the Co(DPM)2 shows a tetrahedral configuration. The copper(II) complex of this ligand and the nickel(II) derivative are planar. The 3-phenyl-2,4-pentanedione derivative of copper(II) also is planar (7). 

All ligands receive a separate subject entry, e.g., 2,4-Pentanedione, iron complex. The headings Ammines, Carbonyl Complexes, Hydride complexes, and Nitrosyl complexes are used for the NH, CO, H, and NO ligands. 

OS , cycto-Octasulfur monoxide, 21 172 O2C5H8, 2,4-Pentanedione, iron complex,... 

OS8, cyc/o-Octasulfur monoxide, 21 172 02C2H6, 1,2-Ethandiol, 22 86 02CjH8, 2,4-Pentanedione, actinide and lanthanide complexes, 22 156 cobalt complexes, 23 94 iron complex, 21 94... 

Acinetohacter johnsonii is able to degrade acetylacetone (2,4-pentanedione), utilizing a novel dioxygenase enzyme, as shown in Figure 40. The purified enzyme is dependent upon Fe for activity, implying that it is a nonheme iron-dependent dioxygenase. labeling studies and structure—activity relationships have been carried out... 

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