Syntheses and Structures of Acetyl‐Acetonato‐Alumo‐Diphenylsilanolates with Magnesium(II), Iron(II), Iron(III), Cobalt(II), and Nickel(II)

Bis(acetylacetonate)alumo‐oxo‐tetraphenyldisiloxane‐metal(II) dihydrates [(acac) 2 Al(O–SiPh 2 –O–SiPh 2 –O)] 2 M (H 2 O) 2 ( M = Mg, Fe, Co, Ni) were obtained from the corresponding acetyl‐acetonate‐dihydrates (acac) 2 M (H 2 O) 2 by reaction with the alumosiloxane [O–Ph 2 Si–O–SiPh 2 –O] 4 Al 4 (OH) 4 . These new compounds display two acac ligands at the aluminum atoms as well as disilatrioxy chains linking the two aluminum atoms forming a (Al–O–Si–O–Si–O) 2 cycle (X‐ray structure analyses). Within this cycle the divalent metal ions M 2+ , to which two water molecules in trans positions are linked, are installed in almost planar M O 4 coordination spheres. Using water free (acac) 2 Ni a different product forms: both reactants combine in a 2:1 ratio to yield [O–Ph 2 Si–O–SiPh 2 –O] 4 Al 4 (OH) 2 O(OH 2 )Ni 2 (acac) 4 . Here, three of the acac ligands were transposed to the aluminum atoms. The nickel atoms are in a distorted octahedral coordination mode from oxygen atoms of the ligands. When iron(III)tris(acetylacetonate) reacts with the alumosiloxane [O–Ph 2 Si–O–SiPh 2 –O] 3 Al 2 O(OH)Fe 2 (acac) 3 was isolated, in which the two iron atoms still display one of the acac ligands. One of the aluminum atoms is in a tetrahedral oxygen environment, whereas the other is in the center of a trigonal bi‐pyramid formed of oxygen atoms either of the siloxane or of acac. The iron atoms have five‐ or sixfold coordination from oxygen atoms of siloxane, acac, hydroxide or oxide.