ФИЗИКО-ХИМИЧЕСКИЕ ОСНОВЫ НАНОТЕХНОЛОГИИ Профессор Н.Г. Рамбиди

11. Нанохимия

Молекулярный дизайн

Были подробно рассмотрены: -молекулярные аспекты синтеза природного каучука, -принципы конструирования молекулы хироптицена – переключающегося молекулярного элемента, -молекулярная память на основе молекул ротаксанов.

Краун эфиры Negative charge concentrated in the cavity of the molecule Negative charge concentrated in the cavity of the molecule Forms stable lewis acid / lewis base with complex Forms stable lewis acid / lewis base with complex Cs +

Formation of Calixarenes Phenol is reacted Formaldehyde and NaOH then heated Phenol is reacted Formaldehyde and NaOH then heated

Calixarene Configuration

Molecular binding The facing pairs of aromatic rings of the calixarene in this conformation form two cavities that are each pre- organized for partial insertion of a Cs+ ion. The facing pairs of aromatic rings of the calixarene in this conformation form two cavities that are each pre- organized for partial insertion of a Cs+ ion. Crystal structures of model complexes with cesium salts have demonstrated a significant dual pi- interaction between the facing aromatic rings and the guest Cs+ ion. Crystal structures of model complexes with cesium salts have demonstrated a significant dual pi- interaction between the facing aromatic rings and the guest Cs+ ion. Cs +

Фуллерены

Фуллерены

Фуллерены

Nontraditional Fullerenes enclosing metal atom clusters. - Three fused pentagons in the C 68 cage: Violation of the Isolated Pentagon Rule (IPR). - Strong gain of stability upon incorporation of NSc 3 in the C 68 cage Sc 3 68 Use of Fullerenes enclosing metal atom clusters as Novel Magnetic Resonance Imaging contrast agents ?

Fullerenes with incorporated Helium Clusters He 60 ( D 2d ) 60 (I h ) - NMR studies on noble gas atoms enclosed in fullerene shells ( M. S. Syamala et al., JACS 124, 6216, 2002 ). - He n encapsulated fullerenes of extraterestial detected in geological sediments ( L. Becker et al., Science ). He n configurations in fullerene cages?

С ложные молекулярные системы

Organic, polymer/biopolymer synthesis Building blocks with natural and synthetic components for site directed self assembly into functional nanostructure

Organic synthesis: from single molecules to molecular assemblies, building block libraries, self-assembling components, liquid crystals, electroactive materials, photonic materials, chromophores, sensor elements… Combinatorial synthesis: libraries of ligands or catalysts, lead discovery and exploitation. Polymer synthesis: polymers with controlled sequence and/or architecture, dendrimers, porous and reactive media, surface coatings. Hybrid materials: organic-inorganic, biological-artificial.

Light harvesting: natural and synthetic ring antennae Rings of chlorophylls and carotenoids funnel harvested energy to reaction center (RC). Subsequent energy transfer steps lead to the production of ATP.

Self-assembly of a receptor from H-bonded molecular building blocks Reinhoudt et al. Guest =

Электроактивные материалы

Governing Equation of Dielectric Elastomers p= 0 E 2 Where: –p is effective compressive stress – is relative dielectric constant – 0 is permittivity of free space (a constant) –E is strength of electric field between diodes

Искусственная рука

Протезы сердца

Микро-насос

Applications: Heel-Strike Generator DoD is using dielectric elastomers to develop a heel-strike generator to go in soldiers boots that would generate electricity just from walking A dielectric elastomer generator works like an actuator in reverse (mechanical-to-electrical instead of electrical-to-mechanical energy)

Responsive materials

Основные пути формирования сложных молекулярных систем

Самоорганизующиеся амфифильные системы

Surfactant Molecules: Oil-Water Building Blocks Monolayer formation Micelles - nano-reactors, drug delivery vehicles, and cleaning agents Oil-Water Interface Oil Water Surfactant Polar head group Non polar tail CH 2 CH 3 OSO 3 -

Micelles in the Bulk Solution Formation of stable aggregates at the cmc. low concentration high concentration

Micelles Polar water-like surface Apolar oil-like interior nm Normal in waterReversed in oil Solubilization Nanoreactors Oil Recovery Drug Delivery

Monolayer formation Surfactants can also adsorb at the air-water interface Adsorption at the air-water interface

Amphiphiles phosphatidyl choline lyso- phosphatidyl choline dodecylsulphate Polar Non-polar

Critical micelle conc

Micelles/Monolayers/Bilayers polar non-polar polar non-polar polar non-polar

Lamellar phase Amphiphiles PC - forms lamellar phases = bilayers of biology Get x-ray/nmr data

Lipid bilayers

Hexagonal phase Amphiphiles PE -forms hexagonal phase = fusion regions of biology

Пленки Ленгмюра- Блоджет

Langmuir Films Spread on water. Not equilibrium adsorption. Film can be compressed Water subphase Air Langmuir film

On Water S-Azo-C18 Isotherm Stearic Acid Isotherm Area (cm 2 ) Surface Pressure (mN/cm 2 ) Area (cm 2 ) Surface Pressure (mN/cm 2 ) Water Gas Water Liquid Water Solid

Langmuir-Schaeffer Films Water subphase Solid substrate

Langmuir-Blodgett Deposition Hydrophobic Surface (OTS ) Water Hydrophilic surface Hydrophobic Surface

Multilayer ~ 10 nm Head to head Tail to tail Head to tail Tail to head X Y Z

The Instrument

Хемосорбированные слои

Chemisorption Chemical reaction between the building block and the solid substrate X X X X X X X XXXXXXXXX Reactive site Spontaneous irreversible Functionalized surface

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OTS on Glass OTS– octadecyltrichlorosilane

OTS on Glass OTS coated substrate surface

Membrane Structure

Types of membrane proteins

Membrane Protein Structure

Формирование заданной последовательности аминокислот в молекуле белка. Синтез Меррифилда

Solid phase peptide synthesis (SPPS) The Nobel Prize in Chemistry for his development of methodology for chemical synthesis on a solid matrix --for his development of methodology for chemical synthesis on a solid matrix Robert Bruce Merrifield Rockefeller University

Традиционный химический синтез

Синтез Меррифилда

Easier!!

Prepare fully protected peptide!

ABI 433A Peptide Synthesizer

Синтез Меррифилда

Coupling efficiency and final yield Yield (%) efficiency (%) 10-mer20-mer30-mer40-mer50-mer60-mer