Triphenylsilyl perchlorate revisited: /sup 29/Si and /sup 35/Cl NMR spectroscopy and x-ray crystallography showing covalent nature in both solution and the solid state. Difficulties in observing long-lived silyl cations in the condensed state

/sup 29/Si and /sup 35/Cl NMR spectroscopic and X-ray crystallographic study of triphenylsilyl perchlorate shows it to be a covalent perchloryl ester in both solution and the solid state. The results are in accord with earlier studies notably those of Wannagat but contrast the recent claim by Lambert etal. (J. Am. Chem. Soc. 1986, 108, 2482) for NMR observation of long-lived ionic triphenylsilyl perchlorate.