Post on 04-Oct-2020
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
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