Professor Jadwiga Frelek
phone. +48 (22) 343 22 15 / 22 12
A detailed list of all possible measurements as well as a respective order form can be found on the home page of the Team XIII »
Electronic Circular Dichroism spectroscopy (ECD) is a widely used method for the determination of the absolute structure of molecules in solution and in a solid-phase. It is rapid, sensitive and reliable technique for determining 3D structure (not only configuration but also conformation), provided that the substance is chiral, non-racemic, and absorbs circularly polarized light (CPL) in the available spectral range (180 - 1100 nm).
The Laboratory of Optical Spectroscopy is equipped with two modern ECD spectrometers with an extensive range of accessories and attachments which allows recording of the high quality spectra for a wide range of chiral compounds.
Our services include:
- ECD measurements in solution or in a solid-phase;
- ECD variable temperature measurements within the -196 °C to +250 °C temperature range;
- ECD kinetics measurements;
- linear dichroism measurements (LD);
- measurements of fluorescence detected circular dichroism (FDCD);
- automatic titration measurement with ECD, UV-VIS, ORD, LD, and FDCD detection;
- HPLC separations with ECD, OR, UV-VIS, and RI detection.
Spectropolarimeter ECD Jasco J-815, for solid-phase measurements (photo above);
Spectropolarimeter ECD Jasco J-715.
ORD spectroscopy is technique complementary to the electronic circular dichroism spectroscopy (ECD) and it records the variation of optical rotation of chiral substances as a function of the wavelength of linearly polarized light. ORD spectroscopy is used in the analysis of optically active compounds, including no-absorbing systems, or absorbing outside the commercial spectral range of typical spectropolarimeters. Among the transparent or absorbing compounds in the difficult-to-access spectral range, a very important for their biological activity substances such as: sugars, amino acids, diols, amino alcohols, etc. may be mentioned. The application of ORD spectroscopy will facilitate stereochemical analysis of those groups of compounds within the 185 nm to 700 nm spectral range.
- ORD measurements in solution at the constant temperature;
- variable temperature measurements;
- kinetics measurements.
Spectropolarimeter ORD Jasco J-815 (photo above).
VCD spectrometer records the vibrational circular dichroism spectra in the infrared range. VCD can be regarded as an extension of electron circular dichroism spectroscopy (ECD) to the IR range, where the oscillatory transitions occur only within the ground-state of the molecule. Thus, correlation of an experimental data with the result obtained from ab initio calculations (DFT) is greatly facilitated. In comparison with ECD the range of applications of VCD for structural studies of chiral substances is much larger. It is due to:
- no need to have a chromophore in the molecule;
- greater number of possible vibrational transitions than the electronic transitions in the molecule;
- the possibility of determination of absolute configuration/conformation independently of previously formulated empirical rules.
The Laboratory of Optical Spectroscopy is equipped with the latest generation of VCD spectrometer with the spectral range 4000 - 850 cm-1. Introduction of Dual Source and Dual PEM technology to VCD spectroscopy, has opened new possibilities for analysis of samples in the solid phase.
Our services include:
- measurements of VCD spectra in solution and solid-phase;
- temperature-dependent measurements in aqueous solution.
ChiralIR-2X TM DualPEM BioTools spectrometer (photo above).
We also offer assistance in the selection of appropriate chiroptical methods (ECD, ORD, OR, VCD) to solve specific stereochemistry problems.
UV-VIS-NIR spectroscopy encompases the ultraviolet, visible and near-infrared region of the electromagnetic spectrum. This technique is routinely used for the qualitative and quantitative analysis of any chemical compounds containing in their structure chromophoric system. A specialized equipment of the Laboratory of Optical Spectroscopy allows to analyze samples in the range from 190 nm to 2700 nm using both the transmission and reflected methodologies, in solution and in a solid phase.
- UV-VIS-NIR measurements in solution or in a solid-phase;
- kinetics measurements.
Jasco V-670 UV-VIS-NIR spectrophotometer (photo above);
UV-VIS Varian spectrophotometer Carry 100E.
Infrared spectroscopy allows to analyze structure of molecules (and detect functional groups), and their interaction with the environment. This is one of the main methods used in the study of hydrogen bonds. The Laboratory of Optical Spectroscopy carries out analytical services in the advanced generation of FTIR spectrometers and sampling accessories for analysis of solids and liquids using transmission and reflectance (ATR) techniques.
- IR measurement by means of transmission technique;
- IR measurement by means of reflectance technique (ATR accessory with diamond or zinc selenide crystal).
Equipment:Spectrophotometer FTIR Jasco 6200 (photo above);
Spectrophotometer FTIR Spectrum 2000 Perkin Elmer.
Samples for all quantitative measurements are weighed on a microbalance Excellence Plus XP26 Micro from Mettler Toledo with accuracy of ± 0.001 mg in range up to 22 g. The balance is equipped with an anti-static set, a draft shield and a printer.
We also offer a possibility to carry out the non-standard analyses at Client's request after prior case-by-case consultation with our analytical staff. The analytical reports are delivered as a hard-copy printouts and/or as a computer files, in format acceptable to our Clients (such as txt, pdf etc.).