Structure-property relationships and salt selection for functional organic materials

  • Aiden Walls

Student thesis: Master's Thesis

Abstract

Eleven salt forms of salicylic acid were prepared, all of which contained strontium or calcium as counterions with nine of the eleven samples containing a mix of both metals which occupied the same crystallographic site. Ten of these forms were successfully characterised by single crystal diffraction, these shared the formula [Ca(1-x)Srx(C7H5O3)2(OH2)2] with x having the following values: 0, 0.041, 0.083, 0.165, 0.306, 0.529, 0.632, 0.789, 0.835 and 1.The calcium to strontium ratios of each sample was also measured using atomic absorption spectroscopy and reported. The aqueous solubility of each sample was also measured. Systematic changes to structure and to solubility with changing metal ratio are reported.Thirteen previously unpublished organic complexes of 4-nitrophenol (NPOH or 4-nitrophenolate NPO) were prepared and had their crystal structures elucidated.These were: 1S2R-(+)-methylephedrine-NPO, 2-amino-3-pyridinecarboxaldehyde -NPOH, 4-acetylpyridine-NPOH, 2-aminobenzylamine-NPO, dimethylpiperidine-NPO(H2O), dipropylenetriamine-NPO, 1S2R-(+)-ephedrine-NPO(MeCN)2, ethanolamine-NPO, n-methylpyrollidine-NPO-NPOH, Rhodamine B-NPOH(MeCN)2 ,tris-2-amino-ethylenetriamine-NPO(H2O)2, isopropylamine-NPO(H2O) and 1,4-diaminobutane-NPO.These 13 structures were compared to 50 structures containing NPOH or NPO found on the Cambridge Structural Database (CSD).Hydrogen bonding and other intermolecular interactions were studied extensively in an attempt to find common interactions which could be linked to the apparent tendency for 4-nitrophenol materials to crystallise in non-centrosymmetric space groups. This included a study of packing analysis and graph set notations. Two separate isostructural groups of cocrystal of salt structures were found to share packing similarities. Potential links between non-centrosymmetric packing and hydrogen bonding, chemical type and pKa values are evaluated.
Date of Award1 Oct 2017
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorAlan Kennedy (Supervisor) & (Supervisor)

Cite this