Synthesis and Structural Characterization of Monomeric Manganese( II ) N ‐Heterocyclic Carbene Complexes [MnX 2 (C{N( i Pr)C(Me)} 2 ) 2 ] (X = Cl, I, and MeCOO)

Reaction of MnCl 2 (THF) 1.5 , MnI 2 , or Mn(MeCOO) 2 with two equivalents of N ‐heterocyclic carbene [C(Me)N( i Pr)] 2 C ( 1 ) in THF at room temperature readily afforded the corresponding carbene adducts [MnX 2 (C{N( i Pr)C(Me)} 2 ) 2 ] [X = Cl ( 2 ); X = I ( 3 ); X = MeCOO ( 4 )] in good yield. Solid‐state structural analysis of complexes 2 − 4 reveals that all complexes are monomeric. In complexes 2 and 3 the central manganese atoms are four coordinate and have a distorted tetrahedral geometry. The manganese atom in compound 4 has a coordination number of six and resides in a highly distorted octahedral geometry. The N ‐heterocyclic carbene ligands in these complexes are coordinated differently to the central metal atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)