The ESR-Study of Chemical Interactions in Triple Solid ‘Ag-CCl₄-5CB’ Co-Condensate Mesogenic System

ABSTRACT

The possibilities of new metal-mesogenic complex formation and their solid phase chemical reactions have been demonstrated using low temperature co-condensation techniques and ESR-spectroscopy for a solid triple system, containing silver, the mesogenic ligand 4-pentyl-4-cyanobiphenyl (5CB) and an alternative electron-acceptor ligand or the third reactive component carbon tetrachloride (CCl₄). It was shown by ESR-spectroscopy that the existence of four paramagnetic products were stabilised in the system at low temperatures: silver atom π-complex with two cyanobiphenyl molecules, silver atom σ-complex with cyanobiphenyl molecule stabilised by CCl₄ co-ligand, AgCl⁻CCl₃• and silver nanoclusters, formed by silver atom aggregation in the mesogenic matrix. The relative thermal stability of these silver species and their thermal behavior are discussed.

Keywords:

• carbon tetrachloride
• ESR spectroscopy
• metal mesogens
• silver complexes
• three-phase solid

Acknowledgments

The work was financially supported by RFBR grants 02-03-32469, 04-03-32748, Russian Federal Programme “Universities of Russia” and INTAS grant 2000-00911.