A study of the interactions between ylidic phosphorus species and organic acids

Abstract

This thesis describes the synthesis and characterisation of phosphonium aryloxides, amides and phosphides. These compounds have been formed via the deprotonation of organic acids [of the type ROH, and R(_2)X, where X = NH, PH, R = aryl group] by basic phosphonium ylidic species [R(_3)PX, X = CH(_2,) C(Me)H, C(Ph)H, NH] in mixtures of hydrocarbon (toluene) and/or polar (acetonitrile, thf) solvents. All of these compounds contain both acidic CHs and 'naked' anions which promote extensive hydrogen bonding. Chapter 1 provides an outline of the fields of ylidic chemistry and hydrogen bonding. In Chapter 2, general experimental methods are described. Chapter 3 records all experimental results pertaining to this work. Here preparation of starting materials is documented, followed by an account of the synthesis and characterisation of twenty-three compounds. For all compounds melting point measurements, (^1)H NMR, (^31)P NMR, infrared spectra, and elemental analysis are recorded. Discussion of these results is documented in Chapters 4 to 7. Where possible, solid-state structures for compounds obtained by single crystal X-ray diffraction (nineteen structures) and single crystal neutron diffraction (two structures) are included. Chapter 4 discusses simple phosphonium aryloxide salts, while Chapter 5 is concerned with related phosphonium amides and phosphides. Chapter 6 deals with an extension of this work involving multifiinctional organic acids. Finally, Chapter 7 discusses unexpected results resulting from the work described in Chapter 6.