The Department of Chemistry

Spec, Thermal, and X-ray Facility

Spectrophotometry Fourier Transform-Infrared:

Absorption of light in the 4000 to 400 cm-1 range is used to identify functional groups in molecules due to peaks occurring at characteristic frequencies.

Available Instrumentation:

  • Perkin Elmer 1760 Infrared spectrometer with the following accessories:
    • Spectra-Tech IR Plan microscope
    • Diffuse reflectance (DRIFT)
    • Horizontal attenuated total reflectance (HATR)
    • Multiple internal reflection (MIR) accessories
  • Detectors include both TGS and MCT
  • Zeiss Stemi 2000 stereomicroscope
  • Mattson Alpha Centauri Infrared Spectrometer Applications of Fourier Transform - Infrared
  • General Infrared
  • Characterization of chemicals
  • Quantitative analysis of known compound in mixtures
  • Aid in determining structure of unknown
  • Microscope (used when microsampling is required)
  • Identify contaminants
  • Examine multi-layered laminates
  • Examine coatings and films
  • Surface defects
  • Diffuse Reflectance
  • Analyze powders directly without making pellets
  • Horizontal Attenuated Total Reflectance
  • Characterization of liquids, pastes or compressible powders, films or solids
  • Multiple Internal Reflection
  • Characterization of thin films

Ultraviolet/Visible Spectrophotometry:

Absorption of light in the 190 to 820 nm range can be used to determine or follow the concentration of molecules containing conjugated systems.

Available Instrumentation:

  • Hewlett Packard 8452A Diode Array Spectrophotometer with the following accessories:
    • magnetic stirrer
    • temperature control
    • data station
  • Spectral range = 190 - 820 nm at a maximum range of 1 scan/0.1 sec.

Applications of UV/Vis Spectrophotometry:

  • General survey scans for qualitative analysis
  • Reaction kinetics using single to full wavelength range
  • Quantitative analysis of single or multiple components

Fluorescence:

The emission of electromagnetic radiation from an excited singlet state of a molecule to its corresponding ground singlet state. The technique exhibits superb detection limits (to "single molecule levels" with a laser and proper optics) and provides information about the photophysics of the emitting species and/or the local environment surrounding the fluorescence center.

Available Instrumentation:

  • SLM 8100 spectrofluorometer with a wavelength range of 200-900 nm. The spectral resolution is adjustable from 0.25-32 nm. The system is capable of the following basic experiments:
  • Steady-state excitation and emission scanning as well as synchronous scanning
  • Fixed wavelength intensity acquisitions
  • Time-dependent intensity data for ms or slower kinetic experiments
  • Steady-state polarization/anisotropy experiments

Applications of Fluorescence Spectroscopy:

  • Determine fluorophore concentration
  • Polycyclic aromatic hydrocarbon screening
  • Determining excitation and emission profiles for unknown or new fluorophores and phosphors that may be applied as new probes, sensor elements, or photodynamic therapy agents
  • Quantum yield determinations
  • Probing the local environment surrounding the fluorophore (pH, dipolarity, mobility)
  • Protein-protein interactions
  • Vesicles
  • Forster energy transfer
  • Host-guest/protein-ligand binding studies and binding equilibria
  • Polarization immunoassay
  • Enzyme kinetics
  • High-pressure (hydrostatic) experiments to 3 kbar
  • Solid-surface luminescence

Consulting:
For help in designing an appropriate experiment, please contact:
Professor Frank V. Bright
Phone: (716) 645-6800 ext. 2162
Email:

Thermal Analysis:

Thermal analysis is used for the characterization of materials by monitoring changes in physical or thermal properties as a function of time and temperature. They are often used to certify product quality of plastics, thermoset materials, foods, and elastomers.

Differential Scanning Calorimeter:

Measures energy flow and temperature associated with chemical reactions or changes in physical state.

Available Instrumentation:

  • Perkin Elmer DSC-7 with:
  • Drybox
  • Liquid N2 cooling, temperature range is -170°C to 725°C.
  • Normal sample size is 0.5 to 30 mg

Applications of Differential Scanning Calorimetry:

  • Melting point
  • Glass transition temperature
  • Kinetics
  • Specific heat
  • Degree of cure
  • Study of chemical reactions/state changes

Thermogravimetric Analyzer:

Used to study process where weight changes as a function of time or temperature.

Available Instrumentation:

  • Perkin Elmer TGA 7
  • The temperature range is room temperature to 1000°C
  • The balance sensitivity is 0.1 mg and the sample size is 2 to 50 mg

Applications of Thermogravimetric Analysis:

  • Water or volatile content
  • Temperature dependent chemical reactions (loss of CO2 etc.)
  • Decomposition temperature/limit of stability
  • Component quantitation in mixtures
  • Quantitation of fillers and reinforcing agents in plastics
  • Curie print measurements

Single Crystal X-Ray Structural Analysis:

We are equipped with an APEX II Bruker diffractometer for X-ray diffraction data collection on single crystals. Final information will include the following:

  • Table of information on X-ray diffraction experiment, including unit cell, space group, reflections collected, agreement indices etc.
  • Table of atomic coordinates.
  • Table of bond lengths.
  • Table of anisotropic displacement parameters.
  • Table of positions of hydrogen atoms.
  • Illustration of molecular geometry. Other information - torsional angles, least-squares planes, packing of molecules in the crystal - may be obtained upon request. Size of crystals required - ideally about 0.3 mm in all three dimensions for a typical organic compound; smaller for crystals containing heavier elements.
  • Crystallographic Information File (CIF)

Consulting:
For help in designing appropriate experiments, please contact:
Professor Jason Benedict
Phone: (716) 645-4276
Email: jbb6@buffalo.edu

Facilities

Facilities

Facilities

The Department of Chemistry