The CD exciton chirality method is a versatile and unambiguous method for the microscale determination of absolute configurations and conformations of organic molecules in solution. It is particularly powerful when two different chromophores are involved since the coupled CD covers a wide spectral range and becomes a fingerprint for that compound. This paper describes the preparation, properties, and applications of three p-amino-substituted Schiff base chromophores to derivatize primary NH2 groups for the exciton chirality method; the Schiff bases are formed in high yield under mild conditions and yield chromophores which also couple with O-acyl chromophores, Moreover, protonation of these Schiff bases yields cyanine-type chromophores exhibiting drastically red-shifted (ca. 100 nm) and 2-3-fold intensified CD couplets. The aldehydes p-(dimethylamino)benzaldehyde, julolidinecarbaldehyde, and p-(dimethylamino)cinnamaldehyde form Schiff bases with aminocyclohexane to yield Chromophores-I, -II, and -III, respectively. These chromophores have the following lambda(max) (epsilon values) for the neutral and protonated species, respectively : Chrom-I, in MeCN 305 nm (24 300), in MeCN/TFA 395 nm (51 700); Chrom-II, in MeCN 331 nm (21 400), in MeCN/TFA 240 nm(48 300); Chrom-III, in MeOH 361 nm (37 000), in MeOH/TFA 460 nm (64 500). NH2 groups are converted into Schiff bases without protection of OH groups; in cases where N,O coupling was required, the OH was converted into the (4-methoxyphenyl)-2,4-pentadienoate (Chrom-IV), in MeOH 333 nm (40 000). All neutral Schiff bases and protonated Schiff bases of (1R,2R)-trans-cyclohexanediamine gave exciton-split CD curves with intense amplitudes. However, in the case of protonated Chrom-III, inversion of the CD sign occurred in 45 min at room temperature in methanol and hence the CD should be measured soon after protonation; NMR and MM2 calculations show that the imminium bond in one of the protonated Schiff base chromophore undergoes an E --> Z isomerization. Derivatives with Chrom-I and -II do not isomerize, and amplitudes of the exciton couplet remain unchanged. Furthermore, the original substrate may be recovered quantitatively when derivatized with Chrom-I. Intense exciton coupling is still observed between chromophores with absorption maxima as far apart as 134 nm.