FT-IR%20microspectroscopy:%20a%20powerful%20tool%20for%20spatially%20resolved%20studies%20on%20supports%20for%20solid%20phase%20organic%20synthesis

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FT-IR microspectroscopy a powerful tool for
spatially resolved studies on supports for solid
phase organic synthesis
Lisa Vaccari
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Outline

• Source for Imaging and Spectroscopic Studies in
  the Infrared
• Beamline layout
• MidIR experimental station
• FT-IR Microspectroscopy
• Solid phase organic synthesis
• Introduction
• Reaction Kinetic
• Diffusion Process
• Acknowledgements

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Layout of SISSI
Source for Imaging and Spectroscopic Studies in
the Infrared
Radiation is collected over a solid angle of 65
mrad (H) x 25 mrad (V)
M1 Plane mirror M2 Ellipsoidal mirror M3 Plane
mirror M4 Ellipsoidal mirror
a 3.5 m d 1.5 m b 1.0 m e 1.0
m c 11.5 m f 2.5 m
d
c
a
b
e
f
M1 Plane mirror M2 Ellipsoidal mirror M3 Plane
mirror M4 Ellipsoidal mirror
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Experimental stations
Switching Mirror (M5)?
2nd branch
1st Branch (CNR-INFM)? Solid State Physics High
Pressures Time-resolved spectroscopy 2nd Branch
(Elettra)? Biophysics/Biochemistry Spectroscopy
and Imaging
VERTEX
Hyperion 3000
IFS66/v
Hyperion 2000
1st branch
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MidIR Microspetroscopy
Visible
Microwaves
Mercury-Cadmium-Telluride Detector Active area of
250X250 mm2 Operation range 600- 9000 cm-1
Focal Plane Array detector 64X64 pixels 2.5X2.5
mm2 active area Operative range 900-4000 cm-1
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Chemical Imaging
Generate Image Contrast by Using Vibrational
Spectral Properties
Chemical Sample Mapping
Chemical Sample Imaging
Vibrational spectra of a sample point by point
irradiating small sample areas
Vibrational spectra of many sample points
Irradiating the full field of view
Single point MCT detector
64X64 pixels of FPA detector
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Lateral Resolution
Diffraction Limited d 0.61 l / NA
Objective NA Wavelength d
15X 0.4 10 mm (1000cm-1) ?15 mm
15X 0.4 2.5 mm (4000cm-1) ? 4 mm
36 X 0.5 10 mm (1000cm-1) ?12 mm
36 X 0.5 2.5 mm (4000cm-1) ? 3 mm
FPA Detector FPA Detector
Objective Pixel resolution
15X ? 2.6
36X ? 1.1
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Acquisition Time vs Sensitivity
MCT Detector Scan Velocity 20 KHz Number of scans
32 Spectral resolution 4 cm-1 2.36 spectra per
second SNR ? 10-5 au Easily usable with SR
FPA Detector Scan Velocity 6 KHz Number of scans
32 Spectral resolution 4 cm-1 3048 spectra per
second SNR ? 10-3 au Special applications
with SR
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MIR Performance of SISSI

• Development of Globar-FPA/Synchrotron-MCT
  combined approach
• Fast acquisition of sample images with FPA
  detector to check sample quality and to identify
  regions of interest
• Higher quality map collection exploiting the
  brightness advantage of SR and major sensitivity
  of MCT detector

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Solid Phase Synthesis
Large compound libraries of peptides,
oligonucleotides and small molecules (drugs)
Distribution of reaction products into the bead
can gives information on pore wettability and
accessibility, efficiency of the reactant
diffusion process, load capacity of the bead and
reaction kinetics BEAD PERFORMACES
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Optical Transparent Polymeric Resins
Annie Y. Bosma, Rein V. Ulijn, Gail McConnell,
John Girkin, Peter J. Halling and Sabine L.
Flitsch Using two photon microscopy to quantify
enzymatic reaction rates on polymer beadsChem.
Commun., 2003, 2790 - 2791
Non-Optical Transparent Polymeric Resins
ATR powder Flatten Single bead microscopy
ATR Microscopy
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Synbeads
Rigid methacrylic polymeric beads Non-swelling
and rigid support High mechanical
stability Versatile - Controlled porosity and
different chemical functionalities Recyclable
Synbeads type Average pore diameter (nm) Average pore diameter (nm) Average pore diameter (nm)
Synbeads type 30 40 80 100 200 250
Amino-Methacrylate A110 A210 A310
Carboxyl-Methacrylate X110 X210 X310
Hydroxymethyl-Methacrylate H110 H210 H310
Chloromethyl-Methacrylate C110 C210 C310
In collaboration with Pharmaceutical Science
Department of Trieste University (Prof. L.
Gardossi, A. Basso, S. Cantone, L. Sinigoi) and
Resindion Mitsubishi Chem. Corp. (Milano)-
www.resindion.com-
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Test reaction - kinetic - 1 -
Amino-Methacrylate beads A310 average pore
diameter of 200-250 nm
Reaction time5,10,20,30,40,60 min 1eq polymer-
3 eq nitropropionic acid Bead loading 0.85
mmol/ gr dry
Evanescent field propagation
Sample
Ge
Detector
Source
Ge (n14), ? 45, organic medium n2 1.5 dp
(1550cm-1) 428 nm
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Test reaction - kinetic - 2 -
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Test Reaction Diffusion - 1 -
Infrared Microscopy is a label free assay
FPA Images 64 scans, 4cm-1
5µm thin bead sections Average diameter 150-170
µm
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Test Reaction Diffusion - 2 -
FPA Images, 64 scans, 4cm-1
Reaction time 10 min
Reaction time 30 min
Reaction time 60 min
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Test Reaction Diffusion - 3 -
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Test Reaction Diffusion - 4 -
SR-FTIR Microspectroscopy. 5µm spatial
resolution, 256 scans, 4cm-1
10 min
20 min
30 min
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Conclusion and future developments

• We propose a new approach for spatially resolved
  studies of chemical distribution based on the
  combination of two FTIR microscopic techniques
  Conventional Source-FPA/SR-MCT detector
• The high spatial resolution and fast acquisition
  time of FPA detector are exploited for a rapid
  screening of the samples to identify the best
  ones to be measured
• The major sensitivity of MCT detector and high
  brightness of SR source are exploited to
  highlight spectral features otherwise not easily
  detectable
• The proposed approach is sensitive and fast
  enough to be employed for a systematic study of
  reaction kinetics and diffusion mechanism for
  solid phase chemistry and to be extended to
  others scientific problems

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Acknowledgements Trieste University
Pharmaceutical Science Department Prof. Lucia
Gradossi, Alessandra Basso, Sara Cantone and
Loris Sinigoi SISSI group M. Kiskinova, D.
Eichert, F.Morgera G. Birarda and D. Bedolla S.
Lupi, A. Perucchi, R. Sopracase,
Thanks for your attention