Silicon complexes acetylacetone

The first ionic hexacoordinate complexes, silicon-tris-acetylacetonate cations (176), were reported as early as 1903 by Dilthey196a and Rosenheim and coworkers196b. Subsequently many other /i-diketonate complexes were studied197-199, and the subject was extensively reviewed7,200 and will not be discussed further here. 

Selenium, bis(diethyldithiocarbamato)-stereochemistry, 60 Selenium, bis(dithiofurancarbamato)-stereochemistry, 60 Selenium(II) complexes bis(dithiochelate), 60 Selenocyanate complexes linkage isomers, 186 Selenonium ions, trifluoro-stereochemistry, 37 Self-exchange reactions, 333 electron transfer rate constants, 347-353, 366 rate constants calculation, 348 rate constants, 362 Semicarbazide, 1,4-diphenylthio-ruthenium determination, 546 Semi-glycinecresol red metallochromic indicator, 557 Semi-xylenol orange metallochromic indicator, 557 Seven-coordinate compounds stereochemistry, 69-83 Sidgwick, Nevil Vincent, 16 Silicon, tris(acetylacetone)-configuration, 195... 

The preparation of silicon-fiinctionalised acetylacetonate rhodium complexes of the type [Rh(L)(Ti2.C2H4)2] (L = (EtO)3Si(CH2)3C(C(0)Me)2) has been reported . These complexes were readily immobilised on silica, as shown in (8), to produce materials which were active catalysts for the synthesis of trisubstituted alkenes firom simple alkenes and diazoalkanes. The... 

A new type of chiral silicon complexes have been developed recently. By preparation of a Schiff-base from acetylacetone and amino acids from the chiral pool a ligand system is available which allows the preparation of chiral penta-coordinated silicon complexes of type 137 [281]. No racemization has been observed during complex formation with dichlorodiorganosilanes. 

Studies of the base-hydrolysis mechanism for hydrolysis of technetium complexes have further been expanded to an octahedral tris(acetylacetonato)techne-tium(III) [30], Although a large number of studies dealing with base hydrolysis of octahedral metal(III) complexes have been published [31], the mechanism of the tris(acetylacetonato)metal complex is still unclear. The second-order base hydrolysis of the cationic complex tris(acetylacetonato)silicon(IV) takes place by nucleophilic attack of hydroxide ion at carbonyl groups, followed by acetylacetone liberation, and finally silicon dioxide production [32], The kinetic runs were followed spectrophotometrically by the disappearance of the absorbance at 505 nm for Tc(acac)3. The rate law has the following equation ... 

The photostadDility of boron-containing orgamic complexes has been discussed, amd a study maule of the luminescent properties of p-diketonates of disubstituted boron amd of bis-p-diketonatoboron. A novel photochemical alkyl migration from B to C in the dialkyIboryl acetylacetonate complexes (1) ( R-cyclohexyl, Bu, isopinocaunpheyl, R -H R-cyclohexyl, Bu, R -Me ) has appeared. Crossover experiments show that the alkyl migration is essentially intraunolecular Silicon... 

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... 

Exemplificative of a third type of oxygen-bonded acetylacetonate derivative is the compound formed from the reaction trimethylchloro-silane and acetylacetone (77). The product from this reaction is 2-tri-methylsiloxy-2-pentene-4-one. It is to be noticed that this silicon compound contains a dangling ligand even though several chelated acetyl-acetonates of silicon are known. Dangling complexation of potential... 

Formation of a siloxane network via hydrosilylation can also be initiated by a free-radical mechanism (300-302). A photochemical route makes use of photosensitizers such as peresters to generate radicals in the system. Unfor-timately, the reaction is quite sluggish. Several complexes of platinum such as (jj-cyclopentadienyl)trialkylplatinum(rV) compoimds have been found to be photoactive. The mixture of silicone polymer containing alkenyl functional groups with silicon hydride cross-linker materials and a catalytic amoimt of a cy-clopentadienylplatinum(IV) compound is stable in the dark. Under UV radiation, however, the platinum complex imdergoes rapid decomposition with release of platinum species that catalyze rapid hydrosilylation and network formation (303-308). Other UV-active hydrosilylation catalyst precursors include (acetylacetonate)Pt(CH3)3 (309), (acetylacetonate)2Pt (310-312), platinum tri-azene compounds (313,314), and other sytems (315,316). 

---