Crystal Engineering Study of Porphyrins, DPMs, BODIPYs, and Cubanes

Abstract

This thesis consists of three topics, each covering an aspect of crystal engineering: for porphyrins (Chapter 1), BODIPYs and tris(dipyrrinato)metal(III) complexes (Chapter 2), and cubanes (Chapter 3). Each chapter contains its own introduction, results, discussion, and experimental section. There is also a general introduction which briefly describes crystal engineering.

Chapter 1.1 covers the synthesis and subsequent X-ray crystallographic investigation on the efficacy of highly substituted [5,10,15,20-tetraaryl-(X)-2,3,7,8,12,13,17,18-octaethylporphyrin (OETArXP)] as a potential scaffold for molecular cages. A library of porphyrins with a variety of functional groups, such as halogens, alkyl and nitrogenous groups was established through a modified Lindsey porphyrin condensation reaction, followed by a metal insertion, using Cu(II), Pd(II), and Ni(II). Coupled with this, is a detailed discussion on the crystal structures of OETArXP and their metal complexes. This was conducted to assess if these compounds can be used for molecular cages.

Chapter 1.2 gives a detailed discussion on the structure of all core N-methyl-substituted porphyrins that have been synthesised in our lab, and that currently exist in the literature. This chapter focuses mainly on the effects that occur when a methyl group is inserted into the core of a porphyrin in both planar and nonplanar porphyrins.

Chapter 2.1 discusses our recently published results on a family of functionalised BODIPY compounds bearing either an anthracene, pyrene, or perylene on the meso-position and a variety of alkyl core substituents (methyl or ethyl). A structural relationship was established between the alkyl-substitution pattern and their effects the dihedral angle between the BODIPY, and the meso-substituent in the structure. Chapter 2.2 discusses five new structures of tris(dipyrrinato)metal(III) complexes with either an iron(III), gallium(III), or indium(III) centres. In this chapter, the structural difference between the metal(III) complexes of the meso-pentafluorophenyl structures and their para-substituted derivatives was established.

Chapter 3 contains a detailed structural analysis of all currently available (publised and current results from our group) 1,4-disubstituted cubane structures with an emphasis on examining how the cubane scaffold interacts in its solid-state environment.