This project is part of PNII-Ideas and will evolve in the period 2007-2010

    The project intends to implement vibrational circular dichroism spectroscopy as a highly sensitive method for unambigous assignment of absolute configuration. The method entails a comparison of the experimental IR and VCD spectra with those calculated ab initio for a specific configuration. The experimental data base consists of homochiral series of optically active compounds obtained by asymmetric catalysis or by enantiomeric separation by chiral HPLC. For increasing the sensitivity of the probe, specific isotopic labelling at the chiral center will be performed. recording of the experimental spectra will be carried out with an IR spectrometer with VCD extension available  in the center of organic chemistry, the sole operating in east-european countries and one of the few  VCD instruments operating in the whole europe. Simulation of the VCD spectra will be carried out by the most performant ab initio calculations, in co-operation with a partner french laboratory. Comparison between experimental and predicted theoretical spectra for assigning absolute configuration of the studied compounds will provide the original results of the project. dissemination by publications and scientific communications is planned. The success of the project might be completed by organizing in bucharest an workshop on the topic, with international participation. this would be  an opportunity to point-out the scientific potential of the vcd technique, the instrumental endowment of the institution as well as  the expertise of the  team involved in the project. 

 

        Vibrational circular dichroism (VCD) provides new approaches in the determination of three-dimensional structure of chiral molecules in isotropic media. The dynamics of the field is stimulated on one hand by development in experimental techniques and equipment and, on the other hand, by refining in quantum-theoretical methods for predicting the sign and shape of VCD spectra.

         The history of the field is rather new. The VCD measurements have been made till early nineties on home-built instruments, being consequently restricted to highly-specialized laboratories. However, since 1995, FTIR spectrometers with VCD extension are commercially available and the acces of the researchers to vibrational optical activity (VOA) measurements became much easier. One may therefore predict a high potential in scientific productivity in the field for the forthcoming years. A promising research area emerges under these stimula, namely testing the VCD data for their predictive capability. In order to be fruitful, such research area should benefit of high-quality experimental data: complete stereochemical description and reliable VCD spectra, with accurately assigned band over the appropriate spectrum range. The main challenge is, however, extracting the stereochemical information contained in the VCD spectra. At this stage, the current, trivial observation should be turned into prediction. For this purpose, theoretical models or (semi)empirical rules linking configuration and/or conformation to the VCD spectra are required. The reliability of the models is established by comparing (critically) the prediction with experimental data-bases as large as possible.

         The present project is formulated in the above framework and was inspired by a critical mass of favouring facts and circumstances:

         1. Recent acquisition of equipment for chiroptical techniques in the Center of Organic Chemistry:

          - FT-IR instrument with extension for VCD spectra. It should be noted that it is the first instrument operating in the East-European countries. Even more, only a handful of VCD instruments are operating in the whole Europe.  

          - High-performance polarimeter operating at five wave-lengths, with possibility of use as polarimetric detector in HPLC.

         2. The existence of a chiral pool of original compounds, whose configuration has been unambiguously assigned previously.

         3. Current research projects on asymmetric catalysis, expected to provide important optically active compounds, enriching the already existing chiral pool.

         4.  Expertise and experience in quantum-mechanics calculations of the Project Director, as well as a long-standing experience in QSAR field.

         5. Long-standing scientific cooperation between the Center of Organic Chemistry and Laboratory of Dynamic Stereochemistry and Chirality CNRS UMR 6180, Chirotechnology, Catalysis and Biocatalysis under Directorship of  Prof. C. Roussel. So far, this cooperation lead to elaboration of two Ph. D. thesis in co-tutelle and a total number of 12 joint publications and scientific communications. A number of seven young researchers from the Center of Organic Chemistry attended stages of specialization in chiral HPLC under the scientific supervision of Prof. C. Roussel and his team. 

          6. Identification of common interest in theoretical study vs experiment in VCD spectroscopy with the Laboratory Asymmetric Catalysis of Prof. F. Fotiadu at Aix-Marseille III, who agreed to join the team with both-sided expertise in VCD spectroscopy and theoretical calculation.

         In other words, the project benefits from joining teams, experience and equipment, common will and agreed subject for cooperative work.

         The main aim of this cooperative project is to increase the reciprocal transfer of knowledge and expertise between experienced and young researchers within each team and also between the Romanian and French teams. Secondly, but not less important, is the aim of marketing the network VCD instruments, expertise expected to issue from this project in the neighbouring countries (Republic of Moldova, Bulgaria, Hungary). The joint aims are represented in the project as objective called implementation of VCD technique.

        According with these aims, the funds will be directed towards:

- improvement of remuneration.

- acquisition of materials for experimental and theoretical parts of the project.

- research stages of specialization and for Ph. D. thesis for young Romanian researchers in France. 

- organization in Bucharest of an workshop on the topic of the project, with international participation.