1,1,3,3-Tetramethyl-1,3-disila-2-oxa[3]ferrocenophane: improved synthesis and new crystal structure

1,1,3,3-Tetramethyl-1,3-disila-2-oxa[3]ferrocenophane Fe(η5-C5H4)2[Si(CH3)2]2O (1) has been prepared by using an improved method, a reaction of 1,1′-dilithioferrocene·TMEDA with dichlorodimethylsilane followed by hydrolysis. The yield was clearly increased in comparison to the methods known from literature. A new polymorph crystal structure 1A of compound 1 was determined by single-crystal X-ray diffraction at 110 K. Crystals were obtained by slow evaporation of chloroform. Complex 1A crystallises in the orthorhombic space group P212121 with the following cell constants: a=8.498(2), b=11.389(2), c=15.448(3) Å, α=90°, β=90°, γ=90°, V=1495.115 Å3 and Z=4.