Aula #11 - moodle.up.pt · Aula #11. Atoms and Molecules. Intermolecular Forces Liquids and Solids...
Transcript of Aula #11 - moodle.up.pt · Aula #11. Atoms and Molecules. Intermolecular Forces Liquids and Solids...
Aula #11
Atoms and Molecules
Intermolecular Forces Liquids and Solids
States of Mater
e.g. Plasma
Intermolecular Forces Liquids and Solids
Intermolecular Forces Liquids and Solids
Crystal structure
Molecular solids and covalent networks
Diamond Graphite
Layers of .. interactions
Network of covalent bonds (intermolecular interactions)
Intermolecular Forces Liquids and Solids
Molecules are packed with maximum interaction potential. Several
and complex types of intermolecular interactionMolecular solids
hydrogen bonding (Green)
π---π (magenta) interactions
Dispersive interactions
Intermolecular Forces Liquids and Solids
Molecules are packed with maximum interaction potential. Several
and complex types of intermolecular interactionMolecular solids hydrogen bonding (Green)
π---π (magenta) interactionsDispersive interactions
https://www.ccdc.cam.ac.uk/Community/csd-community/freemercury/
• Large number of SCXRD structures of “small” molecules
• CCDC database has ca. 1.000.000 entries
• Metal Complexes
Intermolecular Forces Liquids and Solids
https://www.ccdc.cam.ac.uk/Community/csd-community/freemercury/
X RAY(Experimental determination of structural parameters …powders and monocrystals)
Mercury
Mercury - Crystal Structure Visualisation, Exploration and Analysis Made Easy
Mercury offers a comprehensive range of tools for 3D structure visualization and the
exploration of crystal packing. With a long pedigree and over 10,000 downloads,
Mercury is firmly established as the visualiser of choice within the crystallographic
community.
Intermolecular Forces Liquids and Solids
Macro Molecules are packed with maximum interaction potential.
Several and complex types of intermolecular interactionPolymers
hydrogen bonding (Green)
π---π (magenta) interactions
Dispersive interactions
Fórmula (-CO-C6H4-CO-NH-C6H4-NH-)n
Kevlar (poliamida aromática)
Intermolecular Forces Liquids and Solids
Macro Molecules are packed with maximum interaction potential.
Several and complex types of intermolecular interactionPolymers
Formula (-CH(C6H5)CH2-)n
PS . Poliestireno
Microstruture EPS !!
Intermolecular Forces Liquids and Solids
Macro Molecules are packed with maximum interaction potential.
Several and complex types of intermolecular interactionPolymers
Foams can be flexible or rigid, thermoplastic or physically foamed or chemically foamed
Close Cell Open Cell
Intermolecular Forces Liquids and Solids
shows a close-packed layer with maximum utilization of space
keeping the electroneutrality…Cation +…Anion - InteractionsIonic solids
Intermolecular Forces Liquids and Solids
A ceramic is a non-metallic solid material comprising an inorganic compound of metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds.
The crystallinity of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous (e.g., glasses)
Intermolecular Forces Liquids and Solids
Borosilicate Glass (Pyrex)80% SiO2, 13% B2O3, 4% Na2O, 3% Al2O3:
Intermolecular Forces Liquids and Solids
Structure
2nm
TiO2
Crystal 1
Border
Crystal 2
Amorphous Carbon
Ceramics
Intermolecular Forces Liquids and Solids
An amorphous solid does not possess a well-defined arrangement and long-range molecular order.
A glass fusion product of materials that has cooled to a rigid state without crystallizing
Crystallinequartz (SiO2)
Non-crystallinequartz glass
Intermolecular Forces Liquids and Solids
shows a close-packed layer with maximum utilization of space and
symmetry. Metallic bond (sea of electrons & core metallic ions)
Metallic solids
Intermolecular Forces Liquids and Solids
shows a close-packed layer with maximum utilization of space and
symmetry. Metallic bond (sea of electrons & core metallic ions)
Metallic solids
e.g. ZINC, Zn
Compact hexagonal structure (6 / mmm) (hexagon with one atom centered)
Each Zn atom is surrounded by 12 atoms in equidistant positions
-Crystal structure with high symmetry;
Intermolecular Forces Liquids and Solids
shows a close-packed layer with maximum utilization of space and
symmetry. Metallic bond (sea of electrons & core metallic ions)Metallic solids
Intermolecular Forces Liquids and Solids
Metal Alloys …Phase diagram …. Fe and C Alloy (steel)
IRONCARBONNICKELCHROMIUNMOLYBDENUM& OTHERs
METAL ALLOY:
Steel
IRONCARBON
Stainless steel
n (negative) Type p (positive) Type
Leads to an increased of number of electrons in conduction band.....
Donor atoms of Group XV, P As, Sb
Trivalent element promoting the formation of positive holes ..... Donor atoms of Group XIII, B, Al, Ga
Semiconductors
Semiconductors
EXTRÍNSECOS
n (negativo)
p (positivo)
Si ( 1.1 eV)
0.04 0.044 0.049
Sb P As
B Al Ga
0.0450.057
0.065
+
-
+ -
Band GAP