Date of Award
Master of Science
Dr. K. M. Baines
The synthesis, structural characterization and reactivity of cryptand complexed tin(II) cations (43-46), as well as the reactivity of a cryptand complexed germanium dication 36, are examined in this thesis.
A series of tin(II) cations were synthesized by the addition of cryptand[2.2.2] to a solution of a tin(II) precursor (SnCU, S11I2 or Sn(OTf)2), resulting in the formation of 43, 45 and 46, respectively. An alternative synthetic route for 45 and 46, and the .primary route for 44, involved the addition of the appropriate trimethylsilyl reagent to a solution of cryptand[2.2.2] and SnC^ to perform a halide/pseudohalide exchange.
The reactivity of 36, 43 and 44 were examined as synthons for Ge(II) and Sn(II) compounds. Compound 36 was reacted with a variety of anionic and neutral reagents in the presence of known germylene trapping reagents: N-heterocyclic carbene, 2,3- dimethylbutadiene (DMB) and 3,5-di-tert-butyl ori/jo-quinone (3,5-D'BoQ). The addition of acetylacetone (acac), dibenzoylmethane and their conjugate bases to the cations 36, 43 or 46 was also studied in the absence of a trapping reagent. Anionic or neutral reagents with a low pKa (~9) are required to add to the germanium or tin. The NHC appeared to trap the germylene in good yield, whereas DMB did not give the predicted adduct. Attempts to abstract the halide from 43, 44 and 45 as well as competition reactions between [(15-crown-5)2Sn][OTf]2 and 46 are also examined.
Avery, Jessica C., "CATIONIC CRYPTAND COMPLEXES OF GERMANIUM(II) AND TIN(II): SYNTHESIS AND REACTIVITY" (2011). Digitized Theses. 3279.