Developing organo-Zintl deltahedral clusters as ligands for coordination to transition-metals via their organic tethers

Deltahedral Zintl ions Ge9 are disubstituted with organic fragments that have various functional groups. Some of the latter are appropriate for coordination to transition-metals to eventually form coordination compounds where the organo-Zintl species act as ligands. Examples of [Ge9R2] include R 1⁄4 eCH]CHIm(Me), eCH]CHeC6H4eOMe, eCH]CH-Fc, eCH]CHe(CH2)4eC^CH, eCH]CHeC6H4eC^CH, CH] CHeC6H4eNH2, CH]CH-Py, eCH]CHe(CH2)3eC^N, eCH]CHCH(OEt)2, eC(CH3)2C^CH. Furthermore, the reported coexistence of [Fe(en)3]2þ and [Ge9-(CH]CH-Fc)2] in the structure of [Fe(en)3] [Ge9-(CH]CH-Fc)2] 3.5en shows that some transition metals in 2 þ oxidation state may not oxidize the disubstituted clusters and could potentially coordinate to them. 2012 Elsevier B.V. All rights reserved.