The nature of the lowest energy singlet excited state of the d(10)-d(10) Cu-2(C6H5NNNC6H5)(2) complex has been described theoretically by extended Huckel molecular orbital (EHMO) calculations and experimentally by UV-visible, emission, and polarized emission spectroscopy. The complex is found to be fluorescent at 77 K (tau(F) 2.23 +/- 0.03 ns, (Phi(F) = (2.7 +/- 0.3) x 10(-3)), where no emission attributable to phosphorescence has been observed. This is the first example reported in the d(10)-d(10) dimer family. According to the EHMO model, the lowest energy excitation arises from an intraligand pi system involving some of the metal atomic orbitals to a pi* system almost entirely localized in the nitrogen frames (i.e. pi --> pi*, a(u) --> b(2u)) with some weak metal-to-ligand charge transfer character, i.e. MLCT; Ag-1 --> B-1(2g)). The Cu-2 dimer excitation and fluorescence spectra exhibit some vibrational features which were analyzed by time-dependent theoretical calculations. The excited state distortion (Delta Q) calculated for the two dominant Franck-Condon active modes (1400 and 480 cm(-1)) is 0.050 and 0.067 Angstrom, respectively. Vibrational spectra exhibit peaks at 1368 (Raman and IR) and at 516 (Raman) and 480 cm(-1) (IR), near the ones calculated, assigned to nu(NN) and nu(CuN), respectively. The sign of the Delta Q values is discussed on the basis of the EHMO results and is consistent with a pi --> pi* intraligand/MLCT model.