| OCR Text |
Show 74 The bond Stereomodelso polarizabiiities and Vo were taken from Table 20 The electric transition moment of the 260=m band has of 307 Debye 5'1 for XI, XII and XIII a and its direction in magnitude l-methyl- a closely related chromophore, is 19° (measured anticlock thymine35 ,I wise) from the the polarization is changed in the XI, Ci-C axis chromophore XII and XIII c.k's and 1. from the nuclei, 's c jk In the formation of the 0 4011 shows the Figure of structure X and the as calculated given by the in Table 150 chromophoric center) is cyclonucleosides polarization chromophore of structures LCAO=MO method which gave the The values used for 1039, rk (measured 2Q66 and 2074 for the the keto oxygen and the ether oxygen, respectivelYo58 R JD:o O, 1 X (y = 0°) Figure 41!1110 The polarizations of th? 2u trnsitions prdicted for 045VcyclO=4=hydroxyur1.d1.ne X and the 02_cyclouridines XIVo ring |
