Abstract
The metal salt complexes of some carbonyl-stabilized ammonium and sulphonium ylides were studied by n.m.r. spectroscopy and X-ray diffraction. The crystal structure of the trimethylammonium diformylmethylide (I)–NaClO4 complex forms a continuous network between the octahedrally co-ordinated sodium cations, perchlorate anions, and the ylide molecules. The behaviour of 3J(CHO, CHO) of (I) in solution reveals that the trans,trans structure, in which a metal cation is bound simultaneously to both formyl oxygens, is formed only to a very small extent, if at all. The 1J(CHO) and chemical shift data for (I) indicate that the cations prefer to bond to oxygen, not to the ylide carbon, which is the preferred site in sulphonium ylides. The complex formation free energies (at 25°C in acetone) range between –5.0 and 10.0 kJ mol–1. The formation entropy for the AgBF4 complex of 1-dimipthylsulphonio-4,4-dimethyl-2,6-dioxocyclohexanide is ca. –85 J K–1 mol–1.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
