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

Deltahedral Zintl ions Ge94- 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 = –CHdouble bond; length as m-dashCH-Im(Me), –CHdouble bond; length as m-dashCH–C6H4–OMe, –CHdouble bond; length as m-dashCH-Fc, –CHdouble bond; length as m-dashCH–(CH2)4–Ctriple bond; length of mdashCH, –CHdouble bond; length as m-dashCH–C6H4–Ctriple bond; length of mdashCH, CHdouble bond; length as m-dashCH–C6H4–NH2, CHdouble bond; length as m-dashCH-Py, –CHdouble bond; length as m-dashCH–(CH2)3–Ctriple bond; length of mdashN, –CHdouble bond; length as m-dashCHCH(OEt)2, –C(CH3)2Ctriple bond; length of mdashCH. Furthermore, the reported coexistence of [Fe(en)3]2+ and [Ge9-(CHdouble bond; length as m-dashCH-Fc)2]2- in the structure of [Fe(en)3][Ge9-(CHdouble bond; length as m-dashCH-Fc)2]•3.5en shows that some transition metals in 2 + oxidation state may not oxidize the disubstituted clusters and could potentially coordinate to them.