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Supramolecular chemistry with triptycene-based building blocks : access to new porous materials

University of British Columbia

Synthetic routes to a series of triptycenyl o-phenylenediamines and o-quinones were developed. The oxidation to form o-quinone moieties was found to occur in a stepwise manner, allowing triptycenes with varying number of o-quinone units to be synthesized. Schiff-base condensation of the triptycenyl o-phenylenediamines was used to form triptycene-containing quinoxalines, phenazines, metal salphens, and phenanthrolines. Single crystal X-ray crystallography of the quinoxalines and phenazines showed that the presence of triptycenes resulted in more porous solid-state structures by disrupting efficient packing. Coordination of the quinoxalines with copper(I)iodide resulted in porous, two-dimensional coordination frameworks having solvent-filled channels. These materials retained their crystallinity on loss of the guest solvent and exhibited high thermal stabilities. One of these frameworks adsorbed solvent vapours to regenerate its original channel-containing structure, and was used to selectively remove benzene from samples of contaminated water. The thermally stable nickel salphens were used to study the relationship between internal free volume arising from intrinsic molecular geometry and accessible porosity through gas adsorption. A general trend of increased internal free volume producing increased porosity was observed. The inclusion of triptycene in these salphens was very effective in promoting porosity, with some compounds having accessible surface areas in excess of 400 m2g1. This observed porosity is unique as it arises from only the molecule’s intrinsic porosity and not from assembly into an ordered, porous structure. The salphens were also capable of adsorping hydrogen, with the best compound adsorbing around 1 weight% at a loading pressure of 1 atmosphere. The phenanthrolines were used to chelate copper(I) metal centres to form a bis(phenanthroline) complex. Carrying out the reaction in the presence of a cyanide source also resulted in the formation of a one-dimensional coordination polymer where the mono(phenanthroline) copper complexes are linked together by cyanide ligands, according to the preliminary solid-state structure obtained. One of the triptycenyl o-phenylenediames was used to chelate a platinum (II) metal centre, forming a model compound representative of fragments of target hexagonal and honeycomb structures.

Text

2010-06-30

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/24119

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/