title: Organofluorosilanes as model compounds for 18F-labeled silicon-based PET tracers and their hydrolytic stability: experimental data and theoretical calculations (PET = positron emission tomography).
abstract: Silicon chemistry has only recently been discovered by radiochemists as a straightforward tool for the introduction of (18)F into biomolecules for positron emission tomography (PET) imaging. (18)F-labeled PET tracers must be stable towards defluorination under physiological conditions, but it is known that the hydrolytic stability of the silicon-fluorine bond is determined by the nature of the substituents on silicon. In the presented study we performed an extensive investigation on the hydrolytic stability of various synthesized organofluorosilane model compounds. By means of density functional theory (DFT) methods a theoretical model of organofluorosilane hydrolysis, which correlates with the experimentally determined hydrolytic half-lives, is developed. The calculation of the difference of Si-F bond lengths between the optimized structures of the starting material A and the intermediate structure C allows the estimation of the hydrolytic stability of newly designed compounds. This model permits the facilitated development of improved building blocks for the synthesis of novel (18)F-silyl-modified biomolecules for PET imaging.
authors.affiliation: Center for Radiopharmaceutical Science of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Aileen
authors.initials: A
authors.lastname: Höhne
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.forename: Linjing
authors.initials: L
authors.lastname: Mu
authors.forename: Markus
authors.initials: M
authors.lastname: Reiher
authors.forename: Ulrike
authors.initials: U
authors.lastname: Voigtmann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Klar
authors.forename: Keith
authors.initials: K
authors.lastname: Graham
authors.forename: P August
authors.initials: PA
authors.lastname: Schubiger
authors.forename: Simon M
authors.initials: SM
authors.lastname: Ametamey
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005462:Fluorine Radioisotopes; D006868:Hydrolysis; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D049268:Positron-Emission Tomography / Q000379:methods*; D012821:Silanes / Q000138:chemical synthesis / Q000737:chemistry*; D012825:Silicon / Q000032:analysis* / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D005462:Fluorine Radioisotopes; D012821:Silanes; D014867:Water; D012825:Silicon