Synthesis and crystal structure of a germanium(II) calix[6]arene containing unusual diamidosilyl ether groups

The reaction of Ge[N(SiMe3)2]2 with calix[6]arene generates a germanium(II) macrocyclic product where the six phenolic oxygen atoms are incorporated into either a Ge2NO rhombus, a -OSiMe3 silyl ether group, or two unprecedented -OSi(H)(NH2)2 groups. This species has been characterized by X-ray crystallography and multinuclear (1H, 13C, and 29Si) NMR spectroscopy.