Thesis (MSc)--Stellenbosch University, 2012. / Please refer to full text for abstract

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. / Inclusion and porosity properties of the following supramolecular solid-state hosts were investigated: • 2,7-dimethylocta-3,5-diyne-2,7-diol • 2-methyl-6-phenylhexa-3,5-diyn-2-ol • Dianin’s compound • p-tert-butyl-calix[4]arene • 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxy-2,8,14,20- tetrathiacalix[4]arene • Two discrete coordination metallocycles, [Ag2IMID2](BF4)2 and [Cu2(BITMB)2(Cl)4] All of these compounds form well-defined crystalline host structures. Inclusion phenomena involving encapsulation of liquids were studied using single-crystal x-ray diffraction methods. Several guest-free host structures (α phases) were structurally elucidated and their gas sorption properties were investigated. Studies of the sorption properties of seemingly nonporous materials were carried out to provide insight into this rare phenomenon. Water and iodine sorption by a polymorph of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxy-2,8,14,20- tetrathiacalix[4]arene shows that the conventional perception of sorption through the solid-state requires reassessment. Gas sorption studies were carried out using apparatus devised and presented here. These include sorption apparatus and a device to determine single-crystal structures under controlled gas atmospheres.

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2009. / Co-crystals are excellent materials for studying intermolecular interactions in the solid-state and can be used to further our knowledge of the balance between strong and weak intermolecular interactions. The O–H∙∙∙∙∙∙Narom synthon was chosen as the focus of this investigation of hydrogen bonding motifs. The starting materials selected all have two hydrogen bond donor and/or acceptor sites for the formation of extended networks. All molecules are also aromatic such that the influence of weaker π∙∙∙∙∙∙π interactions can be included in the study. Two 3x3 grids of related co-crystals were produced from these starting materials and are reported in this thesis as part of an ongoing investigation into a broader set of co-crystals. A part of the work describes the investigation of co-crystals prepared by the combination of related benzenediol and diazine isomers taken from a 3x3 grid. The solid-state structures of each of the six starting materials are discussed briefly to describe the nature of intermolecular interactions involved in the single component crystals. Trends in hydrogen-bonding patterns as well as the weaker interactions identified in the starting materials, can be used to recognise those in the subsequent multi-component crystals. Thirteen co-crystal compounds were obtained, of which twelve structures are novel. Each of these co-crystal structures is discussed in terms of intermolecular interactions and packing in the solid state. Hydrogen-bonding patterns and structural similarities are highlighted in related co-crystal structures as well as between co-crystals and their respective starting materials. The combination of benzenediol isomers with benzodiazine isomers yielded seven novel co-crystal structures in a second 33 grid is reported. The structure of phthalazine, which has not yet been reported, is included in addition to these co-crystals, while the structures of quinazoline and quinoxaline that were retrieved from the CSD are discussed briefly. Co-crystal structures are discussed individually, focusing on the intermolecular interactions that are significant to the structural architecture of the compound. Certain co-crystals that display structural similarities with structures of the 3x3 grid, as well as with co-crystals presented in Chapter 3, are discussed in the relevant sections. Lastly, two extended pyridyl diyne ligands that were synthesised for use in future co-crystallisation studies similar to those reported earlier are briefly highlighted. The crystal structures of the pure compounds and of a hydrate of one of the ligands were obtained and discussed briefly. To date only one of these structures has been reported in the literature.

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The number of coordination complexes utilizing bis-pyridyl diamide ligands has increased significantly over the past decade. This is attributed to the relatively easy synthetic procedure of the ligands and interesting structural features such as helicity, water clusters and porosity that the coordination complexes possess. In the first part of this study, the following eight structurally related bis-pyridyl diamide ligands: • N,N'-bis(pyridin-4-ylmethyl)isophthalamide (ISO); • N,N'-bis(pyridyl-4-ylmethyl)terephthalamide (TER); • N,N'-bis(pyridin-4-ylmethyl)hexanediamide (ADI); • N,N'-bis(pyridin-4-ylmethyl)butanediamide (SUC); • N,N'-bis(pyridin-4-ylmethyl)biphenyl-4,4'-dicarbonyl dicarboxamide (DIP); • N,N'-dipyridin-2-ylpentanediamide (GLUT); • (2E)-N,N'-bis(2-pyridin-4-ylmethyl)but-2-enediamide (FUM); • 4-(pyridin-4-ylmethyl)aminocarbonyl benzoic acid (TER-A). were synthesized and characterized by NMR, FTIR, MS and SCD. In the second part, the synthesized ligands were reacted with a variety of transition metal salts to yield fifteen novel coordination polymers and one discrete complex. SCD analysis showed that of the sixteen complexes thirteen formed 1-D chains, two formed 2-D networks, and one formed a discrete unit. Hydrogen bonding interactions between water molecules, the counterions and the amide groups resulted in connection of the lower dimension entities into higher dimension networks. The synthesized ligands were co-crystallized with trimesic acid and a novel co-crystal consisting of ADI and trimesic acid was obtained. SCD analysis showed that the co-crystal featured the amide homosynthon as well as the pyridine/carboxylic acid heterosynthon. / AFRIKAANSE OPSOMMING: Die aantal koördinasie komplekse met dipiridieldiamied ligande het noemenswaardig vermeerder oor die afgelope dekade. Hierdie groei kan toegeskryf word aan die eenvoudige sintetiese prosedure en interessante strukturele eienskappe van dié koördinasie komplekse, wat o.a. helikse, waterbondels en poreuse materiale vorm. In die eerste deel van hierdie studie is die agt onderstaande struktureel verwante dipiridieldiamied ligande se sintese en karakterisering deur kernmagnetieseresonansie, Fourier transform infrarooi, massaspektrometrie en enkel kristal X-straal diffraksie (SCD) beskryf: • N,N'-bis(piridien-4-ielmetiel)isoftalamied (ISO); • N,N'-bis(piridien-4-ielmetiel)tereftalamied (TER); • N,N'-bis(piridien-4-ielmetiel)heksaandiamied (ADI); • N,N'-bis(piridien-4-ielmetiel)butaandiamied (SUC); • N,N'-bis(piridien-4-ielmetiel)bifeniel-4,4'-dikarbonieldikarboksamied (DIP); • N,N'-dipiridien-2-ielpentaandiamied (GLUT); • (2E)-N,N'-bis(2-piridien-4-ielmetiel)but-2-eendiamied (FUM); • 4-(piridien-4-ielmetiel)aminokarboniel bensoësuur (TER-A). In die tweede gedeelte is bg. ligande met 'n reeks oorgangsmetaalsoute gereageer om vyftien nuwe koördinasiepolimere, asook een diskrete kompleks, te lewer. SCD analise toon dat van hierdie sestien komplekse vorm dertien 1-D kettings, twee vorm 2-D netwerke en slegs een vorm 'n diskrete eenheid. Waterstofbindings tussen die water molekules, die teen-ione en die amied groepe het laer dimensie (1-D) eenhede verbind om hoër dimensionele netwerke (2-D) te vorm. Mede-kristallisasie van die gesintetiseerde ligande met trimesielsuur het 'n nuwe mede-kristal tussen ADI en triemesielsuur opgelewer. Enkelkristal diffraksie toon dat die mede-kristal beide die amied homosinton en die piridien/karboksielsuur heterosinton bevat.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The first part of this study describes the synthesis of new porous materials from basic building blocks. Five structurally related ligands namely: N,N'-bis(3-pyridylmethyl)-naphthalene diimide (L1), N,N'-bis(4-pyridylmethyl)-naphthalene diimide (L2), N,N'-bis(4-pyridylmethyl)- pyromellitic diimide (L3), N,N'-bis(3-pyridylmethyl)-pyromellitic diimide (L4) and 2-(pyridin-4- ylmethyl)-benzene tricarboxylic anhydride (L5) were synthesised. Ligands L1 and L2 were reacted with metal nitrates and carboxylates as co-ligands in a systematic manner with a view to obtaining potentially porous 3–D coordination polymers. Ten structurally diverse coordination polymers were obtained and they were characterised by single-crystal X-ray diffraction, powder X-ray diffraction and thermogravimetric analysis. Four of these compounds absorb moderate amounts of CO2 and, in addition, show sorption selectivity towards CO2 over N2. The reaction of L3 and L4 with transition metal halides yielded two 1–D chains, while the reaction of L5 with transition metal nitrates yielded seven coordination polymers of which four are 2–D and three are 1–D. Of the 2–D structures three are isostructural. The second part of this work describes a variable pressure study of a flexible metal-organic framework [Zn2(BDC)2(BPY)] (BPY = 4,4 -bipyridine and BDC = 1,4-benzene dicarboxylic acid). [Zn2(BDC)2(BPY)] is one of the few examples of a flexible metal-organic framework that undergoes phase transformations in response to gas pressure. The high pressure sorption recorded for this metal-organic framework displays two inflection steps in the pressure range 0 to 30 bar, possibly indicating two phase transformations. The gas-loaded structures for each phase transformation were determined by means of single-crystal X-ray diffraction. High-pressure differential scanning calorimetry was also carried out on the system in order to determine accurate gate-opening pressures, as well as the energies involved with each phase transformation. The results correlate with those obtained from single-crystal X-ray diffraction and high-pressure sorption. The final section reports the mechanochemical synthesis of two Werner complexes [NiCl2(4- PhPy)4] (1), [CoCl2(4-PhPy)4] (2) and their corresponding solid solution [Ni0.5Co0.5Cl2(4-PhPy)4] (3) (PhPy = phenyl pyridine). The solid solution could only be formed by mechanochemical synthesis and not by conventional solution crystallisation methods. The solid solution exhibits sorption properties that differ from those of the pure compounds. / AFRIKAANSE OPSOMMING: Die eerste deel van hierdie studie beskryf die sintese van nuwe poreuse stowwe uit basiese boublokke. Vyf struktureel verwante ligande naamlik: N,N'-bis(3-piridielmetiel)-naftaleen diimied (L1), N,N'-bis(4-piridielmetiel)-naftaleen diimied (L2), N,N'-bis(4-piridielmetiel)- piromellitien diimied (L3), N,N'-bis(3-piridielmetiel)-piromellitien diimied (L4) en 2-(piridiel-4- ielmetiel)benseen trianhidried (L5) is gesintetiseer. Ligande L1 en L2 is gereageer met metaal nitrate en karboksielsure as mede-ligande in 'n sistematiese wyse met 'n oog op die verkryging van potensieel poreuse 3–D koördinasie polimere. Tien struktureel diverse koördinasie polimere is verkry en hulle is gekarakteriseer deur enkel-kristal X-straal-diffraksie, poeier X-straal diffraksie en termo-analise (thermal analysis). Vier van hierdie verbindings het matige hoeveelhede CO2 geabsorbeer en, bykomend, wys sorpsie selektiwiteit van CO2 oor N2. Die reaksie van L3 en L4 met oorgangsmetaalhaliede het twee 1–D kettings gevorm, terwyl die reaksie van L5 met oorgangsmetaal nitrate sewe koördinasie polimere opgelewer het, waarvan vier 2–D en drie 1–D polimere is. Van die 2–D polimere het drie vergelykbare strukture. Die tweede deel van hierdie werk beskryf 'n veranderlike druk studie van 'n buigsame metaalorganiese raamwerk [Zn2(BDC)2(BPY)] (BPY = 4,4-bipiridien en BDC = 1,4-benseen dikarboksielsuur). [Zn2(BDC)2(BPY)] is een van die min voorbeelde van 'n buigsame metaalorganiese raamwerk wat fase transformasies (phase transformations) ondergaan in respons op ‘n verandering in gas druk. Die hoë-druk sorpsie aangeteken vir hierdie metaal-organiese raamwerk vertoon twee infleksie stappe in die gebestudeerde druk gebied (0 tot 30 bar), wat moontlik op twee fase transformasies dui. Die gas-gelaaide strukture vir elke fase transformasie is bepaal deur middel van enkel-kristal X-straal-diffraksie. Hoë-druk differensiële skandeer kalorimetrie (differential scanning calorimetry) is ook uitgevoer op die stelsel ten einde dié akkurate hekopenings druk, sowel as die energie betrokke by elke fase transformasie te bepaal. Die resultate stem ooreen met dié verkry vanaf enkel-kristal X-straal diffraksie en hoë-druk sorpsie. Die finale afdeling bespreek die meganochemiese sintese van twee Werner komplekse [NiCl2(4-PhPy)4] (1) en [COCl2(4-PhPy)4] (2) en hul ooreenstemmende vaste oplossing (solid solution) [Ni0.5Co0.5Cl2(4-PhPy)4] (3). Die vaste oplossing kan slegs gevorm word deur meganochemiese sintese en nie deur konvensionele oplossing kristallisasie metodes. Die vaste oplossing vertoon sorpsie eienskappe wat verskil van dié van die suiwer verbindings.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The aim of the work presented in this thesis was to design ionic organic framework materials based on carboxylate salts with the intention of engineering interesting properties, such as porosity, into these framework materials. The first section focuses on the characterisation and porosity studies of an ionic framework material, 3,4-lutidinium pamoate hemihydrate, with THF-filled channels in the solid state. It was shown that this framework is able to exchange the THF in the channels for a wide variety of compounds, with many of these exchanges occurring in a single-crystal to single-crystal fashion. Competition experiments conducted with the framework, both by immersing crystals of the framework in solvent mixtures, as well as by exposing crystals of the framework to mixtures of solvent vapours, indicated that it is able to selectively exchange for one guest over another. The kinetics of exchange of this framework were studied, and it was possible to identify a kinetic model describing this process. A second novel framework-type material, 4-phenylpyridinium pamoate, was identified during the course of this study, as well as five isostructural frameworks containing different guest molecules. In this case the framework consists of discrete units that close-pack in such a way that guest molecules are included in constricted cavities in the solid state. Although this framework-type material is not porous, it is thermally quite stable and also highly selective. It is able to selectively encapsulate 1,4-dioxane when crystallised from various solvent combinations including 1,4-dioxane. In addition, eight novel structures with pamoic acid in combination with various pyridyl derivatives were obtained. A third novel framework material was obtained with N,N'-bis(glycinyl)pyromellitic diimide in which, due to the extended hydrogen-bonded network formed between the constituents of the framework, DMF molecules are aligned in channels. It was found that this framework material can also be formed by mechanochemical synthesis, and investigation of the thermal behaviour of this framework showed that it has the potential to be porous, since the framework appears to remain intact after desolvation. Furthermore, six novel structures with N,N'- bis(glycinyl)pyromellitic diimide in combination with various N-heterocycles were obtained. All structures obtained in this study were also further analysed to determine whether there are particular structural features that are required for framework formation. Insights gained from these investigations, in terms of degree of ionisation of the anion, packing arrangements and hydrogen bonding patterns as well as the molecular shape of the components are discussed. / AFRIKAANSE OPSOMMING: Die doel van die werk wat in hierdie tesis voorgelê word is om ioniese organiese raamwerkmateriale gebaseer op karboksilaatione te ontwerp, met die voorneme om interessante eienskappe in hierdie materiale te bewerkstellig. Die eerste afdeling fokus op die karakterisering en porositeit van ‘n ioniese organiese raamwerkmateriaal, 3,4-lutidiniumpamoaathemihidraat, wat kanale gevul met tetrahidrofuraan (THF) besit. Dit is aangetoon dat dit moontlik is vir hierdie raamwerkmateriaal om die THF in die kanale te verruil vir ‘n wye verskeidenheid stowwe, waarvan baie van hierdie uitruilings geskied as ‘n enkelkristal tot enkelkristal transformasie. Kompetisie-eksperimente is met hierdie raamwerkmateriaal uitgevoer deur die kristalle in mengsels van oplosmiddels te onderdompel, sowel as deur die kristalle aan mengsels van die oplosmiddeldampe bloot te stel. Die resultate het aangedui dat dit moontlik is vir hierdie raamwerkmateriaal om een gasstof selektief teenoor ‘n ander te verruil vir die THF in die kanale. Die kinetika van die uitruilingsproses van hierdie materiaal is ook bestudeer en dit was moontlik om ‘n kinetiese model te identifiseer wat die uitruilingsproses beskryf. ‘n Tweede nuwe raamwerk-tipe materiaal, 4-fenielpiridiniumpamoaat, is deur die loop van hierdie studie geïdentifiseer, sowel as vyf isostrukturele raamwerkmateriale waarvan net die gasstof verskil. In hierdie geval bestaan die raamwerk uit diskrete eenhede wat op so ‘n wyse saampak dat die gasstowwe in vernoude porieë ingesluit word. Alhoewel hierdie raamwerk-tipe materiaal nie poreus is nie, is dit termies stabiel en ook hoogs selektief. Die raamwerkmateriaal kan selektief 1,4-dioksaan enkapsuleer wanneer dit gekristalliseer word vanuit ‘n verskeidenheid oplosmiddel kombinasies met 1,4-dioksaan. Verder is agt nuwe strukture verkry met die pamoaat ioon in kombinasie met ‘n verskeidenheid piridien-derivate. ‘n Derde nuwe raamwerkmateriaal is verkry met N,N'-bis(glisiniel)piromellitiese diïmied waarin, danksy die uitgebreide waterstofgebinde netwerk tussen die komponente van die raamwerk, die DMF molekules in kanale aangetref word. Hierdie raamwerkmateriaal kan deur meganochemiese sintese berei word en verdere ondersoek na die termiese gedrag van hierdie raamwerkmateriaal dui aan dat dit die potensiaal het om porositeit te toon, aangesien die raamwerk behoue bly nadat die DMF molekules verwyder is. Ses nuwe strukture is ook met N,N'-bis(glisiniel)piromellitiese diïmied in kombinasie met ‘n wye verskeidenheid stikstof-bevattende heterosikliese verbindings verkry. Alle strukture wat tydens hierdie studie verkry is, is verder ondersoek om te bepaal of daar spesifieke strukturele kenmerke is wat benodig word vir die vorming van raamwerkmateriale. Insigte wat verkry is vanuit hierdie ondersoeke, in terme van die graad van ionisasie van die anioon, die rangskikking van molekules in die struktuur en waterstofbindingspatrone, sowel as die molekulêre vorm van die komponente, word bespreek.

The crystalline solid state is invaluable to both the pharmaceutical and fine chemical sectors. The advantages primarily relate to reducibility criteria required during processing of stable solid state materials and delivering purification, which is inherently performed by the crystal growth process. A major challenge is achieving control through crystallising solids with the desired physico-chemical properties. If this can be achieved the crystalline solid is of great financial and practical benefit. One emerging methodology for manipulating the solid crystalline form is the application of co-crystals. This work relates to key steps in the understanding of rational design of co-crystals utilizing crystal engineering concepts to determine systems before then applying screening criteria to the selected sub-set. Co-crystal screening is routinely undertaken using high-throughput solution growth. We report a low- to medium-throughput approach, encompassing both a melt and solution crystallization step as a route to the identification of co-crystals. Prior to solution studies, a melt growth step was included utilizing the Kofler mixed fusion method. This method allowed elucidation of the thermodynamic landscape within the binary phase diagram and was found to increase overall screening efficiency. This led to the discovery of a number of co-crystal systems with the co-former nicotinamide, with the single crystal structures determined for the following systems; R/S ibuprofen: nicotinamide, S ibuprofen: nicotinamide, R/S flurbiprofen: nicotinamide and salicylic acid: nicotinamide. To assess the crystallization and phase behaviours of determined co-crystals the R/S ibuprofennicotinamide system was selected and successful studies were undertaken determining the aqueous ternary phase behavior and the pre-nucleation speciation in methanol. There have, as yet, been a limited number of published examples which are concerned with pharmaceutical property enhancement by co-crystals, as vast proportion of the literature concerns the growth and isolation of these novel phases. To elucidate further the pharmaceutical relevance of co-crystals the properties of the R/S ibuprofen- nicotinamide system were then assessed showing a positive profile for this material.

Acenes have been explored by a number of research groups in the field of organic electronics with a particular emphasis on transistor materials. This group has been actively studying acene‐based organic semiconductors for more than a decade using a crystal engineering approach and has developed acene derivatives for applications in field‐effect transistors, light‐emitting diodes, and photovoltaics. In addition to organic electronics, crystal engineering has important applications in a number of other fields, quite notably in the design of metal‐organic frameworks. Chapters 2 and 3 of this dissertation focus on applying crystal engineering to the synthesis of acene derivatives for use as solid‐state, long‐wavelength fluorescent organic dyes in the field of biomedical imaging. More specifically, this work studied the synthesis and properties of dioxolane‐functionalized pentacenes and hexacenes. One of these pentacene derivatives has already been demonstrated in biomedical imaging which may lead to improved treatment of tuberculosis. The dioxolane‐functionalized hexacene is still under evaluation for bioimaging applications. Chapters 4 and 5 focus on crystal engineering in relation to organic electronics. Chapter 4 deals with fine‐tuning of crystal packing and demonstrated that small differences in molecular structure can result in significant changes to the solid‐state structure which affects semiconductor properties. Finally, chapter 5 studies the use of singlet fission in photovoltaics and demonstrated that this process does occur in a solar cell incorporating a hexacene derivative. Pentadithiophenes were also synthesized for singlet fission photovoltaics, but they have yet to be studied further.

Doctor of Philosophy / Department of Chemistry / Christer B. Aakeroy / A family of three 2-aminopyrazine derivatives were prepared and co-crystallized with thirty carboxylic acids. Our theoretical charge calculations and experimental results from 90 reactions demonstrated that decreasing the charge on the hydrogen-bond acceptor sites results in a decrease of the supramolecular yield (the frequency of occurrence of the desired outcome). However, synthon crossover (undesired connectivity) was observed 7/12 times and was unavoidable due to competitive binding sites present in the N-heterocyclic bases chosen. To avoid synthon crossover, we used a strategy based on geometric bias. We utilized hydrogen-bonding two-point contacts and halogen-bonding single-point contacts for supramolecular reactions with the 2-aminopyrazine family of compounds. The desired two-point contact and single-point contact (N•••I or N•••Br) appeared in 9/9 times even in the presence of other potentially interfering intermolecular interactions. In addition, the role of charge in controlling the presence/absence of proton transfer was also highlighted. To establish a hierarchy in halogen-bonding interactions we designed and synthesized a library of eight molecules equipped with two different halogen bond donors and combined with variety of halogen-bond acceptors. 11 Halogen-bonded co-crystals were obtained; however, positional disorder of I/Br atoms obscures a complete analysis. This problem was solved by introducing asymmetry in the halogen-bond donor molecules. Finally, successfully demonstrated an unprecedented hierarchy in halogen-bond interactions based on electrostatics. We developed high-yielding Suzuki-Miyaura coupling reactions of tetraboronic pinacolyl ester cavitand to iodoarenes with a range of functional groups (electron withdrawing/donating group and a heterocycle) that show robustness and versatility, making it a ‘launch pad’ for the synthesis of many new cavitands in a facile manner. We have also successfully demonstrated cavitand functionalization from tetraaldehyde to tetraoximes using ‘solvent assisted grinding’, irrespective of the position of the aldehyde. Finally, we prepared tetra-substituted pyridyl and carboxylic acid cavitands having an ellipsoidal cavity capable of encapsulating asymmetric guest molecules and was subsequently obtained the first of its kind, C[subscript]2v symmetric molecular capsule with encapsulated asymmetric guest molecule.

The research herein presents an approach to stabilising reactive materials by engineering and designing strategies for forming multi-component materials containing the reactive molecules by use of their non-covalent intermolecular interactions. These interactions may be utilised as part of a design approach to create new materials of more beneficial physical and chemical properties for the desired application. The reactive materials focussed on in this research are organic peroxyacids, in particular peroxyacetic acid, meta-chloroperbenzoic acid and 6-phthalimidoperoxyhexanoic acid. The stabilities of these target materials under different conditions are probed to find a suitable environment for crystallisation experiments. Crystal structures of the materials were isolated and characterised and the peroxyacids were subsequently cocrystallised with materials chosen to interact with the target molecules to form new molecular complexes, including carboxylic acids, π stacking materials and metal salts. A hosting approach was also employed to form multi-component systems containing these materials, crystallising them with larger, stable, structure-generating compounds with the aim of intercalating the reactive molecules in their stable structure. To this end, urea based compounds, cyclodextrins and Montmorillonite clay were investigated as hosting materials. Candidate multi-component materials were synthesised which successfully retain peroxyacid reactivity. A second set of materials studied was agrichemicals, which also frequently have reactive character, in which a change in physical properties was pursued by the method of forming new crystalline complexes. Five new crystalline agrochemical molecular complexes were synthesised and tested for thermal stability in comparison to the original materials to assess for changes in properties of the multi-component materials.