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The addition reaction of sulfenyl chlorides of metal acetylacetonates to vinyl-, allyl-, and cyclohexenyl-containing silanes has been studied to form silicon containing chelates of chromium(III), aluminum(III), and cobalt(III). The yields and stability of the chelates depend on the nature of the alkenyl groups and decrease in the order cyclohexeny > vinyl > allyl. The decomposition leads to elimination of chlorosilane, which depends on the stability of the silicon-carbon bond in the obtained chelates. The thermal decomposition of the monomeric chelates proceeds by elimination of chlorosilane and oxidation of the acetylacetonate group. The thermal stability decreases in the order Al > Cr > Co for all compounds, depending on the ease of conversion into the other oxidation states and on the ability of the metal to catalyze the oxidative processes. The aluminum-containing polymers have chelating properties after acidic hydrolysis. [ABSTRACT FROM AUTHOR]

The molecular and crystal structures of chlorine-, bromine-, and nitro-substituted chromium(III) acetylacetonate are determined. Connecting the substituent to the central atom does not change bond lengths and valence angles in metal chelate rings. Studied chromium complexes are characterized by greater intermolecular interactions compared with analogous metal acetylacetonates. In some cases, intermolecular interactions increase the bend of chelate rings along the O⋯O line. Substituents do not interact with chromium ions of neighboring molecules because metal is blocked by three ligands. [ABSTRACT FROM AUTHOR]