Acetylacetone manganese complexes

Mn(acac)3 reacts with ethylenediamine (L2) or other primary amines (L) to yield [Mn"(acac)2L2], which can also be prepared by the reaction of the amine or diamine with [Mn(acac)2(H20)2]. Allylamine reacts with [Mn(acac)2-(H20)2] in ether to give a second complex, [Mn(acac)2(H2NCH2==CH2)]2 which is dimeric both in the solid and vapour phases. This is the First example of a dinuclear manganese(ii) acetylacetonate complex. Thermodynamic data have been reported for the manganese(ii)-acetylacetone system in propan-1-ol-water. ... 

Naphthol can successfully be dimerized oxidatively, selectively through the o-site to give (22) using copper(II)-amine complexes (70%) or manganese(III) acetylacetonate (69%), and o-o coupling is the major paAway (90%) on ferricyanide oxidation of the trisubstituted phenol (23) to the orthodiphenoqui-none (24). In this context it is of interest that a compound obtained (74%) on ferricyanide oxidation of... 

Trichloro(tripyridine)chromium(III), synthesis 36 Tris(3-bromoacetylacetonato)chromium(III), synthesis 37 Cyclopentadienyl tricarbonyl hydrides of chromium, molybdenum, and tungsten, synthesis 38 Trichloro(tripyridine)molybdenum(III), synthesis 39 Potassium octacyanotungstate(IV) 2-hydrate, synthesis 40 Chlorine(CP )-labeled thionyl chloride, silicon tetrachloride, boron chloride, germanium (IV) chloride and phosphorus(III) chloride, synthesis 44 Unipositive halogen complexes, synthesis 46 Monopyridineiodine(I) chloride, synthesis 47 Manganese(III) acetylacetonate, synthesis 49 Triiron dodecacarbonyl, synthesis 52... 

Other methods reported for the determination of beryllium include UV-visible spectrophotometry [80,81,83], gas chromatography (GC) [82], flame atomic absorption spectrometry (AAS) [84-88] and graphite furnace (GF) AAS [89-96]. The ligand acetylacetone (acac) reacts with beryllium to form a beryllium-acac complex, and has been extensively used as an extracting reagent of beryllium. Indeed, the solvent extraction of beryllium as the acety-lacetonate complex in the presence of EDTA has been used as a pretreatment method prior to atomic absorption spectrometry [85-87]. Less than 1 p,g of beryllium can be separated from milligram levels of iron, aluminium, chromium, zinc, copper, manganese, silver, selenium, and uranium by this method. See also Sect. 5.74.9. 

There are now numerous, metal-linked oligomeric (and polymeric) systems that fall into this category. For example, the acetylacetonates of manganese(II), nickel(II) and zinc(II) have long been known to be trimeric while the cobalt(II) complex is tetrameric, with three (3-diketonate oxygen atoms bridging adjacent metal centres in a linear array in each case. Other more recent examples include systems built... 

Apart from the compounds already mentioned, vanadium, manganese, and cobalt chlorides, tetra-alkoxy derivatives of titanium, acetylacetonates of V, Cr, Mo, Mn, and Ni, Cp derivatives of Zr and Nb, and triphenyl phosphine complexes of Ti and Fe were found to be active. Later lanthanide complexes were included in the list of dinitrogen-reducing systems, the most effective being compounds of samarium and yttrium. 

In solution, the monomer of anhydrous Co (AA) 2 apparently is tetrahedral (12), It is reasonable to expect that the monomeric j3-ketoenolate complexes of the alkali earth metals as well as manganese(II), iron(II), zinc(II), cadmium(II), and lead(II) also will be tetrahedral (18). However, in the solid state the manganese(II), iron(II) (19). and zinc(II) (6) complexes with acetylacetone apparently are polymerized (18). The cation B(AA)2" very likely also contains a tetrahedral BO4 unit. 

Series Pd-Mn / SiOa catalysts have been prepared from molecular complexes. The precursors, palladium (II) bis-acetylacetonate and manganese (II) bis-acetylacetonate, were purchased fi om STREM Chemicals Inc. 

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