Internal and External Induced Circular Dichroism in Cyclodextrin Complexes: A Study of the Complexes of α-Cyclodextrin with (R)-3-Methylcyclopentanone and Cyclopentanone

The circular dichroism (CD) of (R)-3-methylcyclopentanone 1 in the presence of a-cyclodextrin (aCx) in -water has been measured. The formation constant (K\u27 = 24 mol-1 litre) of al-l complex, specific CD (do = +1.74) of 1 in water solution, and specific CD of this complex in water (t1c\u27 = +1.4,5)have been calculated. Similarly, the induced CD (ICD) of cyclopentanone 2 in the presence of aCx in water has been measured. The formation constant (K = 25 mol-1 litre) of a 1-1 complex and the specific CD (t1c\u27 = -0.034)of this complex have been calculated. A model is presented for the interpretation of the lCD data. Various theoretical possibi1ities are discussed. A comparison with X-Ray and low-temperature neutron-diffraction data for the (2-aCx) complex is attempted. It seems reasonable to conclude that there is only a weak chiral discrimination in this complex in water solution at room temperature

Internal and External Induced Circular Dichroism in Cyclodextrin Complexes: A Study of the Complexes of α-Cyclodextrin with (R)-3-Methylcyclopentanone and Cyclopentanone

The circular dichroism (CD) of (R)-3-methylcyclopentanone 1 in the presence of a-cyclodextrin (aCx) in -water has been measured. The formation constant (K\u27 = 24 mol-1 litre) of al-l complex, specific CD (do = +1.74) of 1 in water solution, and specific CD of this complex in water (t1c\u27 = +1.4,5)have been calculated. Similarly, the induced CD (ICD) of cyclopentanone 2 in the presence of aCx in water has been measured. The formation constant (K = 25 mol-1 litre) of a 1-1 complex and the specific CD (t1c\u27 = -0.034)of this complex have been calculated. A model is presented for the interpretation of the lCD data. Various theoretical possibi1ities are discussed. A comparison with X-Ray and low-temperature neutron-diffraction data for the (2-aCx) complex is attempted. It seems reasonable to conclude that there is only a weak chiral discrimination in this complex in water solution at room temperature