With the goal of elucidating electronic and conformational effects on structure spectroscopic property relationships in platinum acetylides, we synthesized a series of nominally centrosymmetric chromophores trans-Pt(PBu3)(2)(C=C-Phenyl-X)upsilon, where X = diphenylamino (DPA), NH upsilon, OCH3, t-Bu, CH3, H, F, benzothiazole (BTH), CF3, CN, and NO2. We collected one- and two-photon absorption spectra and also performed density functional theory (DFT) and time-dependent (TD) DFT calculations on the ground- and excited-state properties of these compounds. The DFT calculations revealed facile rotation between the two ligands, suggesting that the compounds exhibit nonplanar ground-state conformations in solution. TDDFT calculation of the S-1, state energy and transition dipole moment for a nonplanar conformation gave good agreement with experiment. Two-photon absorption spectra obtained from these compounds allowed estimation of the change of permanent electric dipole moment upon vertical excitation from ground state to S-1 state. The values are small Delta mu < 1.0 D for neutral substituents such as CH3, H, and F but increase sharply to Delta mu approximate to 11 D for electron-accepting NO2. When in a nonplanar conformation, the corresponding calculated Delta mu values showed good agreement with the experimental data indicating that the two-photon spectra result from nonplanar ground-state conformations. Previously studied related chromophores having extended conjugation (Rebane, A.; Drobizhev, M.; Makarov, N. S.; Wicks, G.; Wnuk, P.; Stepanenko, Y.; Haley, J. E.; Krein, D. M.; Fore, J. L.; Burke, A. R.; Slagle, J. E.; McLean, D. G.; Cooper, T. M. J. Phys. Chem. A 2014, 118, 3749-3759) show similar dependence of Delta mu on the substituents, which allows us to conclude that the excited-state properties of these floppy chromophores are a function of the electronic properties of the substituents, ligand size, and nonplanar molecular conformation.