Two-Coordinate Magnesium(I) Dimers Stabilized by Super Bulky Amido Ligands.
A variety of very bulky amido magnesium iodide complexes, LMgI(solvent)0/1 and [LMg(μ-I)(solvent)0/1 ]2 (L=-N(Ar)(SiR3 ); Ar=C6 H2 {C(H)Ph2 }2 R'-2,6,4; R=Me, Pr(i) , Ph, or OBu(t) ; R'=Pr(i) or Me) have been prepared by three synthetic routes. Structurally characterized examples of these materials include the first unsolvated amido magnesium halide complexes, such as [LMg(μ-I)]2 (R=Me, R'=Pr(i) ). Reductions of several such complexes with KC8 in the absence of coordinating solvents have afforded the first two-coordinate magnesium(I) dimers, LMg-MgL (R=Me, Pr(i) or Ph; R'=Pr(i) , or Me), in low to good yields. Reductions of two of the precursor complexes in the presence of THF have given the related THF adduct complexes, L(THF)Mg-Mg(THF)L (R=Me; R'=Pr(i) ) and LMg-Mg(THF)L (R=Pr(i) ; R'=Me) in trace yields. The X-ray crystal structures of all magnesium(I) complexes were obtained. DFT calculations on the unsolvated examples reveal their Mg-Mg bonds to be covalent and of high s-character, while Ph⋅⋅⋅Mg bonding interactions in the compounds were found to be weak at best.
School of Chemistry, Monash University, P.O. Box 23, Melbourne, VIC, 3800, Australia.
Aaron J
AJ
Boutland
School of Chemistry, Monash University, P.O. Box 23, Melbourne, VIC, 3800, Australia.
Deepak
D
Dange
School of Chemistry, Monash University, P.O. Box 23, Melbourne, VIC, 3800, Australia.
Andreas
A
Stasch
Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO, 135 Avenue de Rangueil, 31077, Toulouse, France. laurent.maron@irsamc.ups-tlse.fr.
Laurent
L
Maron
School of Chemistry, Monash University, P.O. Box 23, Melbourne, VIC, 3800, Australia. cameron.jones@monash.edu.
Cameron
C
Jones
DFT calculations; bulky amides; magnesium(I); metal-metal bonding