Nanochemistry NAN 601 Dr. Marinella Sandros Instructor: Dr. Marinella Sandros Lecture 8: Supramolecular Chemistry
What is Supramolecular Chemistry ? “Supramolecular chemistry is the chemistry of the intermolecular bond, covering the structures and functions of the entities formed by the association of two or more chemical species” J.-M- Lehn "Supramolecular chemistry is defined as chemistry ‘beyond the Molecule’, as chemistry of tailor shaped inter-molecular interaction.” F. Vögtle http://www.waltry.f2s.com/lectures/supra-lec1.pdf
What is Supramolecular Chemistry? “Chemistry beyond the molecule” “Chemistry of molecular assemblies and of the intermolecular bond.” “The Chemistry of non-covalent bond.”
Molecules Supermolecules Supramolecular chemistry involves investigating molecular systems in which the most important feature is that components are held together by intermolecular forces, not by covalent bonds. Atoms Molecules Molecules Supermolecules Covalent Interactions Non-Covalent Interactions
Supramolecular Chemistry http://www.tfp.uni-karlsruhe.de/Summerschool/Lectures/voegtle1.pdf
Supramolecular Chemistry Where did it come from? Inspired from biology and built on the shoulders of traditional synthetic organic chemistry. Why does it deserve to be a field of study all its own? The next logical step in synthetic chemistry; understanding and interface with the biological world; nanotechnology http://www.waltry.f2s.com/lectures/supra-lec1.pdf
http://www.waltry.f2s.com/lectures/supra-lec1.pdf
http://www.waltry.f2s.com/lectures/supra-lec1.pdf
Lock and Key Principle http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Beyond Host/Guest Chemistry Molecular Self-Assembly: Process by which 2 or more molecules interact from a larger structure or organization. Super-Molecule: A complex formed by molecular self- assembly which contains a discrete number of subunits. http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Covalent Bond Energies http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Non-Covalent Interactions: Electrostatic
Hydrogen-Bonded Interactions
Hydrogen Bond http://www.waltry.f2s.com/lectures/supra-lec2.pdf
- Interactions http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Dispersion Forces http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Hydrophobic Effect http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Coordination Bonds http://www.waltry.f2s.com/lectures/supra-lec2.pdf
Supramolecular: Biology The study of non-covalent interactions is crucial to understanding many biological processes from cell structure to vision that rely on these forces for structure and function. Biological systems are often the inspiration for supramolecular research. http://en.wikipedia.org/wiki/Supramolecular_chemistry
Example :DNA
http://www.waltry.f2s.com/lectures/supra-lec1.pdf
How to make a receptor ? people.bio.aau.dk/.../PowerPoint/Supramolecular%20chemistry.ppt
Biotin-Streptavidin malina.ichf.edu.pl/educ/.../WYKLAD_SUPRA_NANO1_2005.ppt
http://www.waltry.f2s.com/lectures/supra-lec1.pdf
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Answer??? http://www.waltry.f2s.com/lectures/supra-lec1.pdf
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Forces Involved in Self-Assembly: http://www.waltry.f2s.com/lectures/supra-lec1.pdf
Interaction Energies http://www.waltry.f2s.com/lectures/supra-lec1.pdf
Chelate Effect Two donor atoms linked together = a chelate (claw) Chelate ligands form much more stable metal complexes than monodentate related ligands (up to 105 times as stable) Ni2+ + L Formation Constants: L = NH3 en trien 2,3,2 8.12 13.54 13.8 16.4 better complementarity faculty.swosu.edu/tim.hubin/InorganicLects/InorgCh12.2.ppt
Chelate Effect Why is favorable?? Thermodynamic Reasons for the Chelate Effect = Entropy
Macrocylic Effect Macrocyclic chelate complexes are up 107 times more stable than non-cyclic chelates with the same number of donors Ni(trien)2+ + H+ Ni2+ + H4trien4+ t½ = 2 seconds Ni(cyclam)2+ + H+ Ni2+ + H4cyclam4+ t½ = 2 years Connecting all of the donors (having no end group) makes k-2 important Breaking the first M—L bond requires major ligand deformation The increase in Ea required greatly slows down k-2 faculty.swosu.edu/tim.hubin/InorganicLects/InorgCh12.2.ppt
Macrocylic Effect The result is a very stable complex as kd becomes miniscule
http://www.waltry.f2s.com/lectures/supra-lec1.pdf
Valinomycin http://www.waltry.f2s.com/lectures/supra-lec1.pdf
Self-Assembly http://www.ciam.unibo.it/photochem/Ri.mo_03.pdf
Supramolecular Assembly They allow access to nanoscale objects using a bottom-up approach in far fewer steps than a single molecule of similar dimensions. The process by which a supramolecular assembly forms is called molecular self-assembly. Some try to distinguish self-assembly as the process by which individual molecules form the defined aggregate. Self-organization, then, is the process by which those aggregates create higher-order structures. http://en.wikipedia.org/wiki/Supramolecular_assembly
http://www.ciam.unibo.it/photochem/Ri.mo_03.pdf
Self-Organization and Self-Assembly http://www.ciam.unibo.it/photochem/Ri.mo_03.pdf
Important Features http://www.ciam.unibo.it/photochem/Ri.mo_03.pdf
Molecular Imprinting http://www.esonn.fr/0oldweb/ESONN04/Lectures/esonn_2004_Mascini3.pdf
Imprinted Polymer-coated QCM Sensors
Molecular Imprinted Polymers http://www.google.com/search?client=safari&rls=en&q=molecular+imprinting+ppt&ie=UTF-8&oe=UTF-8