synchrotron radiation and chemistry
TRANSCRIPT
Synchrotron radiation andchemistry
A. Martorana IX School of Synchrotron Radiation, Duino, 17 september 2007
“the branch of science that deals with the identification of the
substances of which matter is composed; the investigation of their
properties and the ways in which they interact, combine, and
change; the use of these processes to form new substances”
What is chemistry?
analysis of the atomic structure analysis of the electronic structure
properties related to the electronic structure structure-properties correlations
synthesis of compounds to investigate how their constituents interact (and eventually determine atomic structure and electronic properties)
Design (and synthesis) of compounds with sought functional properties
what can be done in chemistrywith synchrotron light?
survey of the chemistry proposals of the GILDAbeamline at ESRF
THIN FILMS OF SULFUR-CONTAINING Pd POLY-YNES ON METAL SURFACES:
INTERFACE PROPERTIES STUDIED BY REFLEXAFS
Sensors, optical devices
organic
reflEXAFS
Structural investigation on inorganic-organic thin layers embedding transition metal
oxocluster s
Functional hybrid
organic-inorganic mater
EXAFS
METAL-ORGANIC FRAMEWORKS: IN SITU SYNCHROTRON XRPD STUDY OF
HOST PROPERTIES AS A FUNCTION OF METAL AND TEMPERATURE
Functional materials
Organic
XRD
Gas sensitive Pt containing Organometallic macromolecules: metal - gas interaction studied by EXAFS
Sensors, optical devices
Organic
EXAFS
The hydration process of Ca3SiO5 and Ca2SiO 4 Structural materials XRD
Local environment of zirconium, yttrium and indium in perovskite proton conductor s Solid electrolytes EXAFS, XANES
The role of silver in the synthesis of gold nanorods Functional
nanomaterials inorganic
exafs
Ag site in Ag/Na ion exchanged waveguides: role of the matrix in the tempearture-driven local stress release
Synthesis, functional
mat inorganic
exafs
The role of Ta reticular accommodation and speciation on the electrochemical properties of SnO2-IrO2-Ta2O5 nanostructured composit e s
Electrochemistry, anode
materials inorganic
exafs
In situ powder diffraction study of thermal behaviour of large-porous aluminosilicate ECR-1
Catalysts XRD
A reflEXAFS study of the early stages of solid state reactions: the formation of MnAl2O4 spinel
Fundamental res
Solid state chemistry
reflexafs
Local order and chemical state of Co and Au in field-assisted ion-exchanged gla s s Study of synthesis proc
edure inorganic
EXAFS
2007
Self-assembly and gas storage of nanoporous crystals Functional materials
(organic)
XRD
Study of Br surroundings in supramolecular system formed by cyclodextrin with
indomethacin
Host-guest, pharmac exafs
TEMPERATURE DEPENDENCE OF UNIT CELL PARAMETERS, POLYMORPHISM
AND STRUCTURAL PHASE TRANSITIONS OF ORGANIC SEMICONDUCTORS
Functional materials
(semicond) Organic
xrd
Probing a supramolecular organic zeolite: solvent uptake and release of a
calix[4]dihydroquinone compoun d
Technology of
nanomaterials organic
xrd
Chemical environment and oxidation state of Co ions in CoAl2O4 f i lms Functional materials
inorganic
exafs
The site of Fe in a new magnetic semiconductor: Fe:Ga N Functional materials
Magnetic inorganic
reflexafs
A XANES investigation of rare-earth doped oxide-based phosphors Functional materials
cathodoluminescence
inorganic
exafs
Local environment of barium, cerium and indium in solid-state protonic conductor s Functional materials
electrochemistry
inorganic
exafs
Local environment of barium cerium and gadolinum in the protonic conductor BaCe(1-
x)GdxO(3-d )
Functional materials
electrochemistry
inorganic
exafs xanes
Adsorption of Se/Fe on Imogolite nanotubes: redox reaction s Storage, catalysts etc exafs
EXAFS on Nb-doped magnesium and magnesium hydride: how the Nb-Mg correlation
acts on the hydrogen absorption/desorption process.
Catalysts exafs
THERMAL BEHAVIOUR OF NEW STANNOSILICATE IN THE AS-SYNTHESIZED AND
CATION EXCHANGED FORM S
Catalysts (zeolite) xrd
2006
Pt, Pd AND Zn CONTAINING ORGANOMETALLIC MACROMOLECULES FILMS AT
METAL INTERFACES: REAL AND MODEL SYSTEMS STUDIED BY reflEXAFS
Functional materials
(optical, sensors)
organic
reflexafs
Pd and Zn containing organometallic macromolecules and oligomers: model systems
studied by EXAFS
Functional mat (optical
sensors) organic
exafs
Guest inclusion properties of a novel calix[4]hydroquinone compou n d Functional mat
(storage, sensors..)
organic
xrd
Local structure of liquid gallium in Ga nanoparticles by Ga-K edge EXAFS Fundamental research exafs
POLYMORPHISM, THERMAL EXPANSION, DEHYDRATION AND PHASE
TRANSFORMATION IN TOBERMORITE AND C-S-H MINERALS
Structural materials
cement
xrd
CRYSTAL STRUCTURE, PHASE STABILITY AND DEHYDRATION PROCESS OF
AFM PHASES
Structural materials
(cement)
xrd
Nd localization in Y(3-x)NdxAl5O12 nano-powd e r Functional materials
(optical) inorg
exafs
TIME- RESOLVED POWDER DIFFRACTION AND PDF ANALYSIS OF
NANOCRYSTALLINE TiO2 MATERIALS
Catalysts xrd
GAS ADSORPTION PROCESS OF Ca0.83CuO2 COMPOSITE CRYSTAL: A
STRUCTURAL STUDY BY TIME RESOLVED DIFFRACTION EXPERIMENT
catalysts xrd
Pt and Ru local structure in Pt/Co and Ru/Co bimetallic catalyst catalysts exafs
EXAFS Analysis of Pd-Au resin supported catalysts catalysts exafs
2005
Structural origin of the reactivity of NiO epilayers and nano-powders catalysts exafs
In situ XRD experiments on Ce/Zr mixed oxides TWC catalysts catalysts xrd
EXAFS and XANES studies on silica and alumina supported La, Mn, Co and Fe
oxides catalysts exafs
IN SITU DIFFRACTION STUDY OF THE TRANSFORMATION PROCESS OF
PdO CATALYTIC MATERIALS
catalysts xrd
EXAFS and high resolution XANES study on the coordination and oxidation
changes undergone by Ironspecies in Fe-zeolites upon template removal and
interaction with oxidative/reductive reagents
catalysts exafs
EXAFS and XANES studies on silica and alumina supported perovkite oxides catalysts exafs
Interstitial oxygen in the Nd1.85Ce0.15CuO4+y by polarised Cu-K edge EXAFS Functional materials
(super conductors)
exafs
Fast phase transformation in metastable PbGeO3 by means of XRPD Functional materials
(optics) inorg
xrd
Local Chemical Environment of Ln(III) ions in Lead Germanate Glasses doped
with lanthanides Functional (optics)
inorg
exafs
Study of the local environment around Te and Ta atoms in tellurite glasses with
amounts of tantalium oxide.
Functional materials
(optics) inorg
exafs
Pd AND Pt CONTAINING ORGANOMETALLIC POLYMER FILMS AT
METAL INTERFACES: REAL SYSTEMS STUDIED BY REFLEXAFS
Functional (optics,
coating) organic
reflexafs
Comparison of XAFS and photocurrent generated by monochromatic X-ray
radiation: the case of metal-phthalocyanine layers.
Functional mat
(optics) organic
exafs
Study of ionic solvation sheaths in mixed aqueous/organic solvents Coordination chem exafs
Probing the early stages of solid state reactions with ReflEXAFS fundamental reflexafs
Time-resolved in situ studies of template-directed nucleation and crystallization in
zeolite synthesis from clear solution.
Synthesis control xrd
2001
2007 2006 2005 2001 total
Functional inorganic 4 7 1 4 16
Functional organic 4 4 3 2 13
structural 1 2 3
catalysts 1 3 4 6 14
Basic res (solid state
chem)
2 1 2 5
Basic (solution
chem)
1 1
have been considered:
proposals explicitly declared as belonging to the chemistry area by the
proposers
have not been considered:
environmental, cultural heritage (shared between chemists, geologists,
physicists) (Quartieri)
are not present:
biochemistry (but a significant number of biophysics have been proposed
on the beamline)
techniques not available on the beamline, but of interest for chemical
applications:
single crystal studies, e.g. protein crystallography (Nardini)
photoelectron spectroscopy (Stefani)
small-angle x-ray scattering (Polizzi)
Imaging (Locatelli)
• High-resolution studies
• In situ studies– Chemical environment
– Temperature
• Time-resolved experiments– Slow processes (e.g. diffusion-limited)
– Fast processes (explt time structure of sl)
applications of SL to chemistry described in this talk
Prussian blue Fe4(III)[Fe(II)(CN)6]3
Fe(III)-N-C-Fe(II)
“ The occurrence of negative thermal expansion (NTE) (i.e., when the material
contracts on heating over a certain temperature range) is relatively rare but has
important technological applications….
Even rarer is the occurrence of zero thermal expansion (ZTE)….
Here we report the unexpected finding that isotropic nearly ZTE … in a large
temperature range between 4.2 and 300 K is exhibited by Fe[Co(CN)6]….
The structural properties of Fe[Co(CN)6] were studied as a function of
temperature between 4.2 and 300 K by high-resolution synchrotron X-ray powder
diffraction ”
J. AM. CHEM. SOC. 2004, 126, 15390-15391
Bistability in prussian blue analogues:
spin crossover change of metal-ligand bond length change of ligand conformation
intervalence electron transfer in AM[M’(CN)6]: M(II)-N-C-M’(III) M(III)-N-C-M’(II)
flexibility of the prussian blue framework in accommodating a wide variety of metals and interstitials
ability of the cyanide bridge in mediating charge transferand spin transition
applications as optical switches, magnetic memories etc.
…X-ray photoirradiation can also trigger controllable structural phase
transformations … in the conducting and magnetic properties of selected material
…A substantial advantage of X-ray-induced phototransformations is that the
stimulus can be simultaneously employed as a probe of the changes of matter
…CsFeII[CrIII(CN)6] was recently reported to be the first member of a Prussian
blue analogue series to display … FeII spin crossover (HS,S=2) (LS,S=0)
…Here we show that X-ray light can induce conversion from the HS to the LS
state of the FeII centers
J. AM. CHEM. SOC. 2006, 128, 8358-8363
Fe(II)LS-N 1.9315 Å Cr(III)-C 2.1100 Å
Fe(II)HS-N 2.1153 Å Cr(III)-C 2.1099 Å
X-ray photoelectrons core holes Auger electrons production local lattice deformation Deexcitation into the LS state due to stronger
electron-phonon interaction
Induction time (percolation threshold)
“We report on the first synthesis of Li-intercalated manganese-phthalocyanine (MnPc) in the
bulk form and on the evolution of the structural and magnetic properties as a function of Li
concentration, x.
….Inserted Li+ ions strongly bond to pyrrole-bridging nitrogen atoms of the Pc rings,
thereby disrupting the ferromagnetic Mn-Na….Mn superexchange pathways. This gradually
induces a crossover of the intrachain exchange interactions from ferromagnetic to
antiferromagnetic as the doping level, x, increases coupled with a spin state transition of the
Mn2+ ions from intermediate spin, S =3/2, to high spin, S =5/2”
Lix[MnPc], 0<x<2
Three-way catalysts
NOx
riduzione N
2
CxHy
ossidazione CO
2
COossidazione CO
2
“The main point addressed is the modification of the
oxygen distribution around the metal center in order to
understand how it can influence the oxygen mobility”
“…in situ structural techniques, X-ray absorption
spectroscopy (XAS) and X-ray diffraction (XRD), are
used to investigate the interaction of Pt nanoparticles
with a Ce0.6Zr0.4O2 mixed oxide”
0’30’90’120’
30’60’
60’90’
Reduction of Pt/CeZr by CO
CeZr
Pt/CeZr
C e r i u m P l a t i n u m ( 1 / 5 )
Pt5Ce alloy
anode 2H2 4H+ + 4e-
cathode O2 + 4e- + 4H+ 2H2O
How a fuel cell works
Perovskite (CaTiO3) structure
“The local structure of yttrium in Y-doped BaCeO3 compounds was
studied using X-ray absorption spectroscopy (XAS) at the Y K-
edge…In situ measurements performed in O2/H2O flux show that …the
observed significative structural changes …point out a preferential
insertion of the hydroxyls around the dopant in the Y-doped BaCeO3
compounds.
“Solvation dynamics, the process of solvent shell reorganization
upon electronic structure changes in a solute, is one of the most
studied processes in chemical dynamics. This is based on its
importance in liquid phase chemistry and in biology, where the
solvent shell has an active role in assisting, hindering, or triggering
chemical reactions”