Yttrium calix[4]arene complexes. Silylation and silylamine elimination reactions on model oxo surfaces

The synthesis and the spectroscopic and structural characterization of lower-rim-silylated and rare-earth-metalated calix[4]arenes are described. Depending on the steric bulk of their silyl groups, disilazane reagents HN(SiMe3)(sub 2) and HN(SiMe2)(sub 2) selectively yield bis- and tetrakis-silylated calix[4]arene derivatives and yttrium silylamide Y[N(SiHMe2)(sub 2)](sub 3)(THF)(sub 2) forms aryloxide bond-linked and silylated moieties on the lower-rim calix[4]arene surface