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The research involved in this thesis is mainly concerned with crystallography and the analysis using crystallographic techniques and methods. The work in this thesis is centered mainly on two types of chemical compounds, photoactive compounds and carbaboranes. The first is the photoactive compounds of biphenyl, its derivatives and similar compounds; these compounds have been studied by diffraction and database analysis. The photochemistry and subsequent structural analysis of biphenyls has been studied in collaboration with Professor Peter Wan at the University of Victoria, Canada. In this study Professor Wan and his group conducted all synthesis and spectroscopic analysis, including the photochemical analysis. In a similar study although not with biphenyls, the a-azidocinnamates were investigated in collaboration with Professor Meth-Cohn of the University of Sunderland. Professor Meth-Cohn and his group conducted all synthesis and spectroscopic analysis. The biphenyl type compounds have also been studied using database analysis to examine the bond lengths, torsion angles, inter-/intra-molecular interactions and general packing conformations and interactions within these structures and this analysis was used to study several conformational anomalies that exist in biphenyl derivative compounds. The second chemical type is carbaboranes; these compounds have been examined in collaboration with Professor Wade's group at the University of Durham. The analysis of carbaboranes centers mainly on hydrogen bonding however also expands into several novel carbaborane structures. Professor Wade and his group carried out the synthesis and spectroscopic analysis.

This thesis can be divided broadly into two halves. The first half (Chapters 3 - 5) deals with crystallographic studies of compounds which contain weak intermolecular interactions or networks of these interactions. Whilst the later part (Chapters 7 - 9) describes the results of database surveys of three novel weak intermolecular interactions. In Chapters 3 and 4 the neutron derived structures of 3,5-dinitrocinnamic acid, 2-ethynyladamantan-2-ol, 2- and 3-ammophenol are presented. All of the compounds contain complex networks of weak hydrogen bonds. The neuron diffraction data are used to determine accurate hydrogen atom poistions and thus characterise these hydrogen bonded networks. Some theoretical work is also described. In Chapter 5, X-ray diffraction studies of a series of iodobenzene derivatives are described. These compounds were synthesised in an attempt to engineer structures mediated by novel X...O(_2)N interactions. The structures of three iodo nitrobenzenes are presented wherein symmetrical bifurcated I...O(_2)N interactions mediate the primary ribbon motif. The structure of TCNQ derivative, in which I...N=C play a structure determining role, is also described. Chapters 7, 8 and 9 describe database smdies of X...O(_2)N, C(ring)-H...O/N and C-F...H interactions. The frequencies and geometries of the interactions were determined and analysed. The data for X...O(_2)N interactions were used in conjunction with sophisticated IMPT calculations to determine prefered interaction geometries and interaction energies. Similar theoretical techniques were used to analyse the C(ring)-H...O/N and C-F..H interactions described in Chapters 8 and 9.Background information and overviews of the general experimental procedures followed when performing the crystallographic and database studies are given in Chapters 2 and 6.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Iowa, 1916.

Thesis (Ph. D.)--Princetin University, 1930. / Reprinted from two articles, by C. Allen Sloat and Alan W.C. Menzles, published in the Journal of physical chemistry, v. 35, no. 7, July 1931.