Synthesis of a monomer for the purpose of self-assembly of tubular aggregates
(2021) KEML10 20211Department of Chemistry
- Abstract
- Supramolecular chemistry is a field in which noncovalent interactions between molecules are utilised to promote the formation of larger molecular assemblies. A single monomer consisting of a bicyclo[3.3.1]nonane backbone equipped with hydrogen bonding motifs and solubilising groups is synthesised. Utilisation of different hydrogen bonding motifs and appropriate solvent renders self-aggregation of a single monomer to a cyclic structure which can be stacked to form a tubular aggregate.
In this thesis the focus lies on the synthetic route for synthesis of a monomer and its constituents. The aim was to execute the synthetic steps in a coherent manner by the utilisation of conventional chemical procedures. The bicyclo[3.3.1]nonane backbone... (More) - Supramolecular chemistry is a field in which noncovalent interactions between molecules are utilised to promote the formation of larger molecular assemblies. A single monomer consisting of a bicyclo[3.3.1]nonane backbone equipped with hydrogen bonding motifs and solubilising groups is synthesised. Utilisation of different hydrogen bonding motifs and appropriate solvent renders self-aggregation of a single monomer to a cyclic structure which can be stacked to form a tubular aggregate.
In this thesis the focus lies on the synthetic route for synthesis of a monomer and its constituents. The aim was to execute the synthetic steps in a coherent manner by the utilisation of conventional chemical procedures. The bicyclo[3.3.1]nonane backbone was synthesised from a series of aldol condensations between dimethylmalonate and paraformaldehyde. Ester hydrolysis of the formed intermediate rendered a diketone which was then subjected to a reduction by employing ordinary Baker’s yeast, resulting in enantiopure compound. Double bonds were added to the backbone which rendered a dienone. The solubilising groups were synthesised in four consecutive steps and added to the dienone via conjugate addition. However, addition of the solubilising groups proved to be difficult due to the sensitive nature of the reaction. After various attempts, a monosubstituted backbone and a disubstituted backbone with impurities was acquired. (Less) - Popular Abstract
- Supramolecular chemistry is often described as “chemistry beyond the molecule”. In simpler terms, supramolecular chemistry is a chemical field in which the interest lies in the formation of larger molecular assemblies. Synthesis of a large and complex molecule is seldom effortless. In the field of supramolecular chemistry, the hardships of covalent synthesis are surpassed, simply by applying familiar molecular concepts.
The main concept regards intermolecular interactions. These kinds of interactions are observable in nature. Intermolecular interactions are present in the very fabric of you and me, namely in our DNA. Our DNA is comprised of base pairs (A, T, C, G) that connect to each other via intermolecular interactions. The very same... (More) - Supramolecular chemistry is often described as “chemistry beyond the molecule”. In simpler terms, supramolecular chemistry is a chemical field in which the interest lies in the formation of larger molecular assemblies. Synthesis of a large and complex molecule is seldom effortless. In the field of supramolecular chemistry, the hardships of covalent synthesis are surpassed, simply by applying familiar molecular concepts.
The main concept regards intermolecular interactions. These kinds of interactions are observable in nature. Intermolecular interactions are present in the very fabric of you and me, namely in our DNA. Our DNA is comprised of base pairs (A, T, C, G) that connect to each other via intermolecular interactions. The very same interaction is observable in water, in fact it is this intermolecular force that gives water its convenient properties such as its relatively high boiling point.
The force is hydrogen bonds, an intermolecular attractive interaction between an electropositive hydrogen atom and an electronegative atom (N, O, F). Hydrogen bonds, among other interactions, are also present in the formation of large and naturally occurring molecular structures such as secondary proteins structures.
The versatility of hydrogen bonds can be employed to avoid complications that accompanies covalent synthesis of large molecules. By mimicking nature, organic compounds with specific hydrogen bonding constituents can be utilised in the creation of a supramolecular assembly, such as a tubular aggregate.
Synthesis of a tubular aggregate is challenging, not to mention the theoretical effort involved. Therefore, a smaller molecule (that can form a supramolecular assembly via hydrogen bonds) is pursued. In this project the main focus is the synthetic pathway behind the formation of such a molecule. Supramolecular studies are beyond the scope of this project.
The molecule needs to be of specific shape and equipped with the proper constituents. Firstly, it needs to be predisposed to maintain a specific shape. In this project the eight-membered bicyclo[3.3.1]nonane-2,6-dione is used as a backbone. Synthesis of the backbone is performed using readily available chemicals. However, the bicyclo[3.3.1]nonane-2,6-dione molecule is chiral. Chirality is a chemical property meaning that a molecule has a ‘mirror-image’ that is non-superimposable. Your left hand and right hand are mirror-images of one another. Your left palm cannot overlap with the backside of your right hand and vice versa; thus, your hands are non-superimposable. An important step in the synthesis of the backbone is that only one mirror-image of the chiral backbone is needed. By employing regular Baker’s yeast used for sweet dough one mirror-image of the backbone can be acquired.
Secondly the molecule needs to be soluble in solvents appropriate for hydrogen bonding. This is achieved by addition of solubilising groups to the backbone. Lastly specific hydrogen bonding motifs must be included so that supramolecular self-assembly can take place.
The molecule of interest can then be manipulated into forming cyclic cavity-containing structures. A structure containing a cavity can host certain compounds. Further manipulation of the hydrogen bonding motifs allows for stacking of the cyclic structures, thereby rendering a tube of nanoscale dimensions capable of acting as a transmembrane channel and potentially facilitating pharmaceutical transport. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9052771
- author
- Khwaja, Sakina LU
- supervisor
-
- Anna Lidskog LU
- Yutang Li LU
- organization
- course
- KEML10 20211
- year
- 2021
- type
- M2 - Bachelor Degree
- subject
- keywords
- organic chemistry, organic synthesis, supramolecular chemistry, self-assembly, self-aggregation
- language
- English
- id
- 9052771
- date added to LUP
- 2021-06-16 11:14:23
- date last changed
- 2021-06-16 11:14:23
@misc{9052771,
abstract = {{Supramolecular chemistry is a field in which noncovalent interactions between molecules are utilised to promote the formation of larger molecular assemblies. A single monomer consisting of a bicyclo[3.3.1]nonane backbone equipped with hydrogen bonding motifs and solubilising groups is synthesised. Utilisation of different hydrogen bonding motifs and appropriate solvent renders self-aggregation of a single monomer to a cyclic structure which can be stacked to form a tubular aggregate.
In this thesis the focus lies on the synthetic route for synthesis of a monomer and its constituents. The aim was to execute the synthetic steps in a coherent manner by the utilisation of conventional chemical procedures. The bicyclo[3.3.1]nonane backbone was synthesised from a series of aldol condensations between dimethylmalonate and paraformaldehyde. Ester hydrolysis of the formed intermediate rendered a diketone which was then subjected to a reduction by employing ordinary Baker’s yeast, resulting in enantiopure compound. Double bonds were added to the backbone which rendered a dienone. The solubilising groups were synthesised in four consecutive steps and added to the dienone via conjugate addition. However, addition of the solubilising groups proved to be difficult due to the sensitive nature of the reaction. After various attempts, a monosubstituted backbone and a disubstituted backbone with impurities was acquired.}},
author = {{Khwaja, Sakina}},
language = {{eng}},
note = {{Student Paper}},
title = {{Synthesis of a monomer for the purpose of self-assembly of tubular aggregates}},
year = {{2021}},
}