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

Deltahedral Zintl ions Ge-9(4-) 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](2-) include R = -CH=CH-Im(Me), -CH=CH-C6H4-OMe, -CH=CH-Fc, -CH=CH-(CH2)(4)-C CH, -CH=CH-C6H4-C CH, CH=CH-C6H4-NH2, CH=CH-Py, -CH=CH-(CH2)(3)-C N, -CH=CHCH(OEt)(2), -C(CH3)(2)C CH. Furthermore, the reported coexistence of [Fe(en)(3)](2+) and [Ge-9-(CH=CH-Fc)(2)](2-) in the structure of [Fe(en)(3)][Ge-9-(CH=CH-Fc)(2)]center dot 3.5en shows that some transition metals in 2 + oxidation state may not oxidize the disubstituted clusters and could potentially coordinate to them. (C) 2012 Elsevier B. V. All rights reserved.