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