Chemistry

Organic

Physical

Inorganic

Organometallics,

Metal Complexes

Clusters,

Cages

Bioinorganic

Solid State

Chemistry

X-ray

Crystallography

Group

Theory

Polymers

What is Solid State Chemistry?

What is Solid State Chemistry?

•Chemical and physical properties of infinite, non-

molecular solids

•Synthesis-structure-property-function relationships

•Materials with properties (or combinations of properties)

tuned for specific applications

•Non-comprehensive, non-mathematical overview

•Chemical aspects of solids

Why Study Solid State Chemistry?

Why Study Solid State Chemistry?

•Materials with properties (or combinations of properties)

tuned for specific applications

Ele

ctr

on

ics:

Diodes, transistors, photodetectors, solar, cells

Op

tical:Fiber optics, CDs, LEDs, lasers, NLO, photon gap, displays

Magn

eti

cs:Switches, data storage, read-write heads, NMR

Ion

ics:Batteries, fuel cells, sensors, displays, smart windows

En

ergy

:Catalysts, chemicals, fuels

Mech

an

ical:Construction, ceramics, composites, alloys, space vehicles, tools

Evn

iron

men

tal:

Pollution prevention and removal, heavy metals, organics, NOx

Sep

arati

on

s:Molecular sieves, membranes, selective catalysis

Bio

mate

ria

ls:Artificial bone, skin, organ replacement, repair, drug delivery

Po

rou

s M

ate

ria

lsP

oro

us

Ma

teria

ls

Name

Pore Size Domain

•Microporous

5 to 20Å

•Mesoporous

20 to 500Å

•Macroporous

> 500Å

•Crystalline or non-crystalline

•Metastable, require soft chemistry methods: crystallization from

gels most common

•Applications: size/shape discrimination for catalysis, ion-

exchange, separation, sensing, host-guest inclusion chemistry,

optical materials, magnetic materials

•Microporous, crystalline: molecular sieves

•Zeolites = (alumino)silicatemolecular sieves

Zeo

lite

sZ

eoli

tes

See Crystal Structure Viewer

See Crystal Structure Viewer

=

•Open framework silicates or aluminosilicates

with ion-exchange properties

•Mn+x/n[(AlO2)x(SiO2)y]x–•mH2O

•[x/(x+y)] of Si sites substituted for Al

•Corner-sharing TO4tetrahedra, T = Al or Si

•No adjacent Al tetrahedra⇒0 to 1 limit of

Al : Si

•Structures drawn with polyhedra or lines

connecting metal centers, ignoring doubly-

bridging oxygens

•β-cage “SBU”

•Zeolite Y: α-cage, connected by 12-ring

windows

•Prof. Sir J. M. Thomas: “On the right, a projected structure of the zeolite we

have been studying…On the left, …a pattern made on the wall of a

mosque…in Azerbaijan in 1086 AD…There is nothing new under the sun.”

•Prof. S. Oliver: “I worked on interlocking stone on a summer job once.”

Sy

nth

esi

s o

f Z

eoli

tes

Sy

nth

esi

s o

f Z

eoli

tes

•Naturally occurring minerals: “boiling stones”

•Naturally occurring as well as new, synthetic zeolite structures

•Synthetic zeolites: 1930’s, Barrer; 1950’s, Union Carbide,

characterized by PXRD

•Reactive, soluble form of silica and alumina

•Formation of a gel precursor: homogeneous, amorphous, alkaline

•Condensation polymerization:

≡Si–OH + HO

–Si≡

→≡Si–O

–Si≡+ H2O

≡Si–OH + HO

–Al≡

→≡Si–O

–Al≡+ H2O

•Hydrothermal synthesis: controlled pH, time, temperature

Hyd

roth

erm

al

Syn

thes

is o

f Z

eoli

tes

Hyd

roth

erm

al

Syn

thes

is o

f Z

eoli

tes

NaAl(OH) 4(aq) + Na 2SiO3(aq) + NaOH(aq)

25°C, Condensation polymerization

Na a(AlO2)b(SiO2)c•H2O, Gel

25 to 250°C, Gel ordering,

Nucleation site formation and growth,

autogenousP

Na x(AlO2)x(SiO2)y•zH2O crystals

Wh

at

Wh

at ’’

s in

a "

am

e:

s in

a "

am

e:

"a

"a

xx(A

lO(A

lO22)) xx

(SiO

(SiO

22)) yy

·· zH

zH22OO

•Open inorganic framework

•One-, two-or three-dimensional networks of interconnected channels

•Channels connect through “windows”to define interior cavities

•Window size determines maximum size of molecule that can enter zeolite

Extr

afr

am

ework

cati

on

s

Charge balancing,

void-filling

(up to 50%),

structure-

stabilizing,

ion-exchangeable

Equal ratio to Al

AlII

I O4, T

d

Each oxygen

shared with

another metal

center

(AlO2)– ,

introduces

negative charge

SiIV

O4, T

d

Each oxygen

shared with

another metal

center

(SiO2), neutral

Occlu

ded

wate

r

Easily removed

by heating

under vacuum,

25 to 500°C

Ap

pli

ca

tio

ns

of

Zeo

lite

sA

pp

lica

tio

ns

of

Zeo

lite

s

•D

ehy

dra

tin

g a

gen

t

•Io

n-E

xch

an

ge

•Zeolite A: water softener in

detergents, exchanges Na+

for Ca2+

•Environmental remediation:

137 Cs, 90 Sr

•A

dso

rben

ts f

or

pu

rifi

cati

on

or

sep

ara

tio

n

•Zeolite A: removal of

n-octane from gas

•Zeolite A: –196°C, O

2

(346pm) adsorbed but N2

(364pm) excluded

•S

ize/

Sh

ap

e S

elec

tiv

e C

ata

lyst

s

•High internal surface area

•Acid sites due to [AlO4]–

Na x(AlO2)x(SiO2)y

Na x-n(AlO2)x-n(SiO2)y+n

(0 ≤n ≤x)

Dealumination, formation

of high-silica zeolites

n SiCl 4(g)

(500°C)

Metal fluoride (aq), (s)

M = B3+, Be2+, Fe3+,

Ti4+, Sn2+, Cr3+,

Al3+, Si4+

Metal-substituted

zeolites

(NH4)+(aq)

(NH4)x(AlO2)x(SiO2)y

450°C,

vacuum

Hx(AlO2)x(SiO2)y

Super

Brønsted

Acid

Catalyst

(M)q+(aq)

Mx/q(AlO2)x(SiO2)y

H2S(g)

(MS) x/qHx(AlO2)x(SiO2)y

Quantum-confined

Semiconductors

ligand

MLn(AlO2)x(SiO2)y

Encapsulated

Transition

Metal Complexes

H2(g)(M) x/qHx(AlO2)x

(SiO2)y

Encapsulated

Metal

Catalyst

Isomorphic

Framework

Substitution

Ion

Exchange

Post

-Syn

thet

ic T

reatm

ent

of

Zeo

lite

s

300 to 400°C

Microporous

material

Siz

e/S

ha

pe

Sel

ecti

ve

Ca

taly

sis

Siz

e/S

ha

pe

Sel

ecti

ve

Ca

taly

sis

Reaction occurs only for

molecules that can enter

zeolite channels

Only molecules that can

exit are present in product

Reaction occurs only for

specific transition state

Zeo

lite

s a

re M

eta

sta

ble

•Molecular sieves are metastable, kinetic phases;

thermodynamically unstable with respect to dense

oxide phases

•Zeolite synthesis obeys Ostwald’s law of successive

reactions: initial metastablephase successively

converts to more thermodynamically stable phase,

finally to most stable phase

•e.g.: Zeolite A →Sodalite→Condensed SiO2+ Al 2O3

Mesoporous

MesoporousMaterials

Materials

•Microporous: 5 to 20Å; Mesoporous: 20 to 500Å; Macroporous: > 500Å

•1992, Mobil

•Mesoporous(alumino)silicates, 15-100Åtunable pore size, high surface

area (> 1000 m2 g–1)

•Inorganic walls are amorphous and lack long-range order

•“MCM-41”, hexagonally packed, uniform cylindrical mesopores

•Structure-directing agent is self-assembled aggregate of amphiphiles

Mes

op

hase

sM

esop

hase

sof

Cof

C12

12HH

25

25"

Me

"M

e33C

l/H

Cl/

H22OO

Sy

nth

esi

s o

f S

yn

thesi

s o

f M

eso

po

rou

sM

eso

po

rou

sS

ilic

aS

ilic

a

So

lven

t

H2O

Ba

se

(NaOHor

TMAOH)

Su

rfa

cta

nt

Alkyltrimethyl-

ammonium halide,

C16H33(CH3)3N+Cl–

Sil

ica

so

urc

e

(Na 2SiO3, tetraethyl-

othrosilicate(TEOS) or

colloidal silica)

•80°C, 1 to 6 days

•Mesoporousaluminosilicateprepared by adding Al 2O3to mixture

•Calcination at 500°yields mesoporousmaterial

•Hexagonally packed cylindrical mesopores

“Hexagonal phase”

Mod

e of

Form

ati

on

of

Mod

e of

Form

ati

on

of

Mes

op

oro

us

Mes

op

oro

us

Sil

ica

Sil

ica

•Self-assembly of amphiphiles into a mesophase (micellar

rod hexagonal phase, lamellar phase or cubic phase)

•Coating by silica: cooperative interaction by ion-pair

formation of surfactant and inorganic species

Tunable

Tunable P

ore

Siz

eP

ore

Siz

e

•CnH2n+1(CH3)3N+n = 12 →

30Åpore size

n = 14 →

34Åpore size

n = 16 →

38Åpore size

n < 8 →no micellarrod formation

•Swollen micellarrods: C16H33(CH3)3N++ auxiliary

hydrocarbon

(e.g.: 1,3,5-trimethylbenzene)

→pore sizes up to 100Å

•Aging sample prepared at low temperature (70°C) in

mother liquor at higher temperature (150°C)

•Post-synthesis silylation, SiH4(g)

Co

va

len

t G

raft

ing

of

Gu

ests

in

toC

ov

ale

nt

Gra

ftin

g o

f G

ues

ts i

nto

Mes

op

oro

us

Mes

op

oro

us

Ma

teri

als

Ma

teri

als

•Silanizationto form methyl-

terminated, hydrophobic channels

•Introduction of functionality:

reaction with tris(methoxy)

mercaptopropylsilane,

(CH3O) 3Si(C3H6)SH

•Formation of terminal thiol

groups, pore size ↓from 36Åto

27Å

•“Highly efficient”removal of Hg

from waste streams

•Renewable by HClwash to

remove Hg

•Adv. Mater. 2

00

0, 12, 1403

Ma

cro

po

rou

s M

ate

ria

ls:

Ma

cro

po

rou

s M

ate

ria

ls:

Aer

og

els

Aer

og

els

•3D metal oxides with pore size > 500Å

•Aerogels: a material prepared by the

replacement of the pore liquid of a gel

with air

•Gel dried supercriticallyto avoid

collapse of 3D framework

•Avoidance of liquid-gas interfaces (liquid

cannot exist above supercritical point)

•Also, freeze drying: pore liquid is frozen

and then sublimed

•Extremely low density materials: ~ 95%

volume is air

•Lowest thermal conductivity of all solids,

optically transparent

•Angew. Chem. Int. Ed. Engl.

1998, 37, 22

Ph

oto

nic

P

ho

ton

ic B

an

dg

ap

Ba

nd

ga

pM

ate

ria

lsM

ate

ria

ls

•Condensation of colloidal silica spheres

to fcclattice:colloidal crystal

•Tunable sphere diameter, 200 to 700nm

lattice parameter

•Also, monodisperselatex spheres

•3D periodic array with repeat distance

on the same order as visible wavelengths

•Bragg diffraction due to presence of two

media with different refractive indices

•Adv. Mater. 1

998, 10, 480

Opal: close-packed

amorphous silica

spheres

Ph

oto

nic

P

hoto

nic

Ban

dgap

Ban

dgap

Tu

nin

g o

f a

Tu

nin

g o

f a

Coll

oid

al

Cry

stal

Coll

oid

al

Cry

stal

Particle size dependence of

optical diffraction

Annealing temperature

dependence of optical diffraction

Inverse Opal

Inverse Opal

1 µ µµµ

m

Opal

Opal

1 µ µµµ

m

Inver

se O

pal

Inver

se O

pal

••MOMO22growth

growth

from

from EtOH

EtOH

••CVD of M

CVD of M

Ozin& coworkers,

Nature2000, 405, 437

Introduce

Inorganic

Remove

Support