The objective of this computational study is to learn about the solution phase, singlet excited-state manifold in conformers of the N-(1-pyrenyl)-1-methyluracil-5-carboxamide nucleoside model (PA-U-Me). In particular this report describes how these manifolds differ between solution and gas phases and among 11 PA-U-Me conformers. Using a CIS INDO/S SCRF theoretical approach, it models the solvent as a dielectric continuum with a spherical solute cavity. This approach is an improvement over intramolecular electron transfer (ET) computations that neglect solvent effects. The results provide considerable insight into the energetics of intramolecular ET in conformers of PA-U-Me, [and by extension into conformers of the previously studied N-(1-pyrenyl)-2＇-deoxyuridine-5-carboxamide nucleoside(PA-dU)]. They show that in the solution phase the PA-U-Me conformers exhibit a strong correlation (R = 0.9) between the energy of their lowest energy singlet ET state (ET1) and its dipole moment. That is, ET1 states with large solution-phase dipole moments are lower in energy than ET1 states with small dipole moments. This result contrasts with results in the gas phase where there is no correlation between the energy of a conformer＇s ET1 state and its dipole moment. In solution phase, several other factors become important in determining the energy of ET product states in addition to the redox and Columbic effects dominant in the gas phase. To summarize, the dihedral angle between the CS-carbonyl and the uracil plane directly affects two electronic properties of pyrenyl-dU conformers. One is the ease of reduction of the uracil subunit, and the other is the extent of HOMO and LUMO delocalization onto the atoms that link the pyrenyl and uracil subunits. In the gas phase, only the first of these effects is important in determining the energy of:ET products, and this effect is modulated by the Coulombic attraction of the cationic and anionic subunits. However, in the solution phase, the extent of HOMO and LUMO delocalization is very important; because delocalization of these:orbitals reduces the dipole moment of their ET products. This work shows that ET1 states with sufficiently large dipole moments (greater than or equal to 24 D) have energies below or equal to the energy of the lowest energy pyrenyl (pi,pi*) singlet state (P-1). Additionally, as long as a trans-PA-U-Me, conformer has an ET1 state below or near the Pi state, there appears to be a good chance that it will have han electronic spectrum like that of the PA-dU nucleoside in solution. [Cis and trans are defined with respect to the NH and CO groups of the amido bond joining the pyrenyl and uracil subunits.] Note that the absorbance spectrum of PA-dU is nearly the same in tetrahydrofuran, acetonitrile, and methanol solvents and is red-shifted from and significantly broader than that of the pyrenyl ligand model N-acetyl-1-aminopyrene. Finally, the computed electronic spectra of cis-PA-U-Me conformers in a polar dielectric continuum (epsilon(s) = 40) do not agree with that of the PA-dU nucleoside in acetonitrile solution.