| The research presented in this thesis involves the synthesis, characterization, and study of carbon-rich molecules. Carbon-rich molecules are of interest because of their remarkable optical and electronic properties due to extended pi-bond conjugation. Conjugated carbon-rich molecules have possible commercial applications, such as in light emitting diodes (LED's), transistors, and sensor technology. The research described here focuses on iodine-containing halocarbon compounds.; Our studies of iodoalkynes reveal an unusual 13C NMR effect. Experiments with 1-iodo-1-hexyne in over 20 different basic solvents demonstrate a significant shift in the chemical shift of the alpha carbon. Empirical chemical models help explain the nature of this effect in terms of a Lewis acid-base interaction between iodoalkyne and solvent.; Using a host-guest system developed by Dr. Frank Fowler and Dr. Joseph Lauher we attempted the polymerization of an iodoalkyne carbon rod. Diiodobutadiyne was co-crystallized with two different host compounds which are pre-designed to align the guest diyne for a topochemical polymerization reaction. Pressure studies using a diamond anvil cell provided the first evidence of the desired polymer, polydiiododiacetylene.; Two iodoalkynes developed in our labs, diiodohexatriyne (C6I 2) and diiodooctatetrayne (C8I2), have been targeted as potential precursors to isolating C6 and C8. For these studies, a low temperature (10 K) matrix-isolation cart was constructed to perform IR and UV argon matrix experiments. The integration and use of a Chen-type hyperthermal nozzle to deposit samples in the matrix provides the versatility of using either photochemistry or pyrolysis to fragment the precursors.; During synthetic work with the iodoalkyne molecules, a fortuitous discovery led to another research project. X-ray crystallography revealed that a sample of diiodobutadiyne (C4I2) had decomposed to become tetraiodobutatriene (C4I4), the first reported iodocumulene. A synthetic route to this novel cumulene was developed, followed by the complete characterization of the halocumulene compound. Two other cumulenes, tetrabromobutatriene (C 4Br4) and dibromodiiodobutatriene (C4Br2 I2) were developed by similar synthetic pathways and then characterized. The properties and chemistry of C4I4, C4Br4, and C4Br2I2, are still under investigation. |
