nanostructural architectures from molecular building blocks
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Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Molecular building blocks:Molecular building blocks: MBBs are the link between classical MBBs are the link between classical
synthsis chemistry from in theory the synthsis chemistry from in theory the smallest possible unit, and large structures.smallest possible unit, and large structures.
MBBs are molecules that self assemble into MBBs are molecules that self assemble into larger units.larger units.
The limitations of this method are:The limitations of this method are: Availability of the units, connectivity, and Availability of the units, connectivity, and
suitable linkerssuitable linkers
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Bonding and connectivityBonding and connectivity– Covalent bondingCovalent bonding– Covalent bonds are formed by the sharing of pairs of Covalent bonds are formed by the sharing of pairs of
electrons between atoms.electrons between atoms.– Best example is the covalent bond between two C Best example is the covalent bond between two C
atoms.atoms.– Sigma bonding along the axis between the two atoms, Sigma bonding along the axis between the two atoms,
provides a means of low energy rotation in linear provides a means of low energy rotation in linear molecules and low energy angle twisting in cyclic molecules and low energy angle twisting in cyclic molecules.molecules.
– Sigma bonding defines the general connectivity and Sigma bonding defines the general connectivity and framework of the molecule framework of the molecule
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Covalent bonding has many advantages:Covalent bonding has many advantages:– Covalent bonds lead to extremely stable Covalent bonds lead to extremely stable
intermolecular connections, as compared to intermolecular connections, as compared to electrostatic interactions (temperature, ionic electrostatic interactions (temperature, ionic strength, pH)strength, pH)
– Covalnet bonds are dependable, they do not Covalnet bonds are dependable, they do not reorganise, like hydrogen bondsreorganise, like hydrogen bonds
– Protocols exist to form all kinds of covalent Protocols exist to form all kinds of covalent bonds for all kinds of building blocks, allowing bonds for all kinds of building blocks, allowing all possible connectivitiesall possible connectivities
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Coordination complexesCoordination complexes– In between the covalent bonds and the other In between the covalent bonds and the other
interamolecular interactions are the coordination interamolecular interactions are the coordination complexes between organic molecules and complexes between organic molecules and metal ions.metal ions.
– The initial description of these metal ligand The initial description of these metal ligand molecules stems from the ability of metal ions to molecules stems from the ability of metal ions to coordinate ligands electron donating molecules coordinate ligands electron donating molecules
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Dative bonds:Dative bonds:– Interaction of a lone pair with an atom centered Interaction of a lone pair with an atom centered
molecular orbital. Strength comparable to a molecular orbital. Strength comparable to a sigma bond.sigma bond.
– E.g. Bonding between B and N.E.g. Bonding between B and N.– Coupling of a molecule to B with a lone pair Coupling of a molecule to B with a lone pair
leads to change in boron from trigonal planar leads to change in boron from trigonal planar (sp2) to tetrahedral (sp3).(sp2) to tetrahedral (sp3).
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Boroadamantane is a special case, because B is already in sp3 hybridisation and has the final conformation already built in the molecule.
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
InteractionsInteractions– They play a role in base stacking in DNAThey play a role in base stacking in DNA– Molecular crystalsMolecular crystals– Polymer chemistryPolymer chemistry– Foramtion, shape and function of proteinsForamtion, shape and function of proteins
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Molecular building block approachesMolecular building block approaches– The ultimate goal is the assembly of nanostructures or The ultimate goal is the assembly of nanostructures or
nanoscale materials through the manipulation of a nanoscale materials through the manipulation of a subunit by chemical modificationsubunit by chemical modification
– The MBB is devisible into one or more The MBB is devisible into one or more chemically/electrostaically active regionchemically/electrostaically active region
Supramolecular ChemistrySupramolecular Chemistry Science of electrostatic interaction at the Science of electrostatic interaction at the
molecular levelmolecular level
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Hydrogen bondingHydrogen bonding It is used extensively in Supramolecular It is used extensively in Supramolecular
ChemistryChemistry Easy means to self assemble large units Easy means to self assemble large units
from smaller subunits, can rearrangefrom smaller subunits, can rearrange Stability increases with the total amount of Stability increases with the total amount of
Hydrogen bondsHydrogen bonds
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Crystal EngineeringCrystal Engineering– Hydrogen Bonding has been extensively used Hydrogen Bonding has been extensively used
in the stabilisation of crystal lattices.in the stabilisation of crystal lattices.– Hydrogen bonding is one of the main bonding in Hydrogen bonding is one of the main bonding in
biological moleculesbiological molecules– Stabilisation of structures and backbonesStabilisation of structures and backbones– Secondary structure stabilisationSecondary structure stabilisation
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Supramolecular structuresSupramolecular structures Whole families of Supramolecular structures Whole families of Supramolecular structures
are known that have been built up only by are known that have been built up only by Hydrogen bondingHydrogen bonding
Mixing the units in te correct ratios will lead Mixing the units in te correct ratios will lead to the self assembly of the desired to the self assembly of the desired structuresstructures
Cavities, sheets, triangular structures,…..Cavities, sheets, triangular structures,…..
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
CatenanesCatenanes– Catenanes are a very special class of Catenanes are a very special class of
supramolecular moleculessupramolecular molecules– They come into existence when two They come into existence when two
macrocycles interpenetrate each other.macrocycles interpenetrate each other.– The first catenane has been synthesised in very The first catenane has been synthesised in very
poor yieldspoor yields
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Molecular ZippersMolecular Zippers– Molecular zippers are formed by amide oliomersMolecular zippers are formed by amide oliomers– They maximise the amount of Hydrogen They maximise the amount of Hydrogen
bonding and bonding and -stacking-stacking– Stabiloity increases with oligomer lengthStabiloity increases with oligomer length– Decrease in stability in polar solvents Decrease in stability in polar solvents
(methanol)(methanol)
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Covalent ArchitecturesCovalent Architectures
The Tinkertoy chemistThe Tinkertoy chemist Idea behind the concept to build all possible Idea behind the concept to build all possible
structures and shapes from a limited set of structures and shapes from a limited set of molecules where all possible connectivities molecules where all possible connectivities of each single are known of each single are known
LEGO block system for organic chemistryLEGO block system for organic chemistry
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Stability:Stability:– Stability and reactivity are the most important Stability and reactivity are the most important
factorsfactors– The MBBS should only react during the The MBBS should only react during the
formation of the structure and result in an inert formation of the structure and result in an inert structure at the end of the reactionstructure at the end of the reaction
SizeSize– Control over the size is better the smaller the Control over the size is better the smaller the
single building blocks are.single building blocks are.
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Chemical reactivityChemical reactivity– From the box of the 24 molecules the reactivity From the box of the 24 molecules the reactivity
and reaction chemistry is known and described.and reaction chemistry is known and described.– Protocols for all possible linking reactions are Protocols for all possible linking reactions are
knownknown– Engineering all possible shapes is possibleEngineering all possible shapes is possible
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Honeycomb lattices
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Symmetry interaction modelSymmetry interaction model– Symmetry interaction model builds on the Symmetry interaction model builds on the
understanding that many highly symmetric understanding that many highly symmetric naturally occuring structures are formed as a naturally occuring structures are formed as a consequence of lock and key interactions consequence of lock and key interactions between the subunits.between the subunits.
– Metal complex chemistry uses these principles Metal complex chemistry uses these principles to generate new metal-ligand assembliesto generate new metal-ligand assemblies
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
2 Dimensional structures2 Dimensional structures Virtually no limit in structural combinationsVirtually no limit in structural combinations
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
3D structures3D structures Spotaneous self assembly from non Spotaneous self assembly from non
covalent self assembly is a known principle covalent self assembly is a known principle in biological structuresin biological structures
ProteinsProteins LaddersLadders RodsRods
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks
Nanostructural Architectures from Nanostructural Architectures from Molecular Building BlocksMolecular Building Blocks