Monomeric Magnesium and Calcium Complexes Containing the Bidentate, Dianionic 1,2‐Bis[(2,6‐diisopropylphenyl)imino]acenaphthene Ligand

Abstract

Abstract The reduction of 1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene (2,6‐ i Pr 2 C 6 H 3 ‐BIAN) with metallic magnesium or calcium in THF affords the monomeric complexes (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Mg(THF) 3 ( 1 ) and (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Ca(THF) 4 ·(THF) 1/2 ( 2 ). The crystallisation of 1 and 2 from benzene causes the removal of one of the coordinated THF molecules, yielding (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Mg(THF) 2 ·(C 6 H 6 ) 1/2 ( 3a ) and (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Ca(THF) 3 ( 4 ). Repeated recrystallisation of 1 from benzene gives (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Mg(THF) 2 ·(C 6 H 6 ) 2 ( 3b ). Although the crystals of 3a and 3b differ in colour and in their crystallographic parameters, their molecular dimensions are very similar. Recrystallisation of 1 from pyridine produces (2,6‐ i Pr 2 C 6 H 3 ‐BIAN)Mg(py) 3 ·(py) 2 ( 5 ). Complexes 1 − 5 have been characterised by elemental analysis, UV, IR and 1 H NMR spectroscopy, as well as by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)