4-«-Pentyl-4 -cyanobiphenyl complexes

Finally, 4-pentyl-4 -cyanobiphenyl (CB), a compound with mesogenic properties, has been co-condensed with europium and samarium atoms. On the basis of matrix IR spectra and DFT calculations at the B3LYP level, it has been proposed that at low temperatures (below 30 K) mononuclear sandwich complexes [(CB)2Eu] and [(CB)2Sm] were obtained while with higher concentration of metal and at higher temperatures bimetallic sandwich complexes [(CB)2Eu2] and [(CB)2Sm2] were present, in which both phenyl rings of CB are coordinated to Eu or Sm (Vlasov et al., 2005). 

The butyl derivative of these nickel complexes was investigated as a dye in a guest-host system using 4-pentyl-4 -cyanobiphenyl (5CB) as the host. The complex was found to have a large extinction coefficient of absorption (e = 28,000 moC dm cm at 860 nm) and dissolved in 5CB at concentrations up to 10% (w/w). At 20 °C, such solutions showed a dichroic ratio (Rd. defined as + /+x = absorbance) of 4.97 and a dye order parameter of 0.57. 

Co-condensates between metallic samarium and 4-pentyl-4 -cyanobiphenyl (5CB) in the solid phase have been obtained via joint atomic/molecular beam deposition on a cooled calcium fluoride surface at liquid nitrogen temperature (Shabatina et al., 2000, 2001, 2005). The film samples have been studied by IR and UVA IS spectroscopy in the temperature range from 80 to 300 K. Two types of complexes were detected, one complex with a metal to ligand... 

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