A series of conjugated (porphinato)zinc(II)-based chromophores structurally related to [5-(4-dimethylaminophenylethynyl)-15-( 5-nitrothienyl-2-ethynyl)-10,20-bis(3,5-bis(3,3-dimethyl-1-butyloxy)phen yl)porphinato]zinc(II) were synthesized using metal-catalyzed cross-coupling reactions involving [5-bromo-15-triisopropylsilylethynyl-10,20-diarylporphinato] zinc(II), [5-bromo-15-(4-dimethylaminophenylethynyl)-10,20-diarylporphinato]zinc(I I), [5-(4-dimethylaminophenylethynyl)15-ethynyl-10,20-diarylporphinato]zinc(II), and [5-(4-nitrophenylethynyl)-15-ethynyl-10,20-diarylporphinato] zinc(II), along with appropriately functionalized aryl, thienyl (or thiophenyl), thiazolyl, benzothiazolyl, and carbazolyl precursors. The linear and nonlinear optical properties of these asymmetrically 5,15-substitued( 10,20-diarylporphinato)zinc(II) chromophores that bear either 2-(9H-carbazol-9-yl)-thiophen-5-yl-ethynyl, 4-dimethylaminophenylethynyl, or 2-(N, N-diphenylamino)thiophen-5-yl-ethynyl electron-releasing groups and an electron withdrawing group selected from 2-formyl-thiophen-5-yl-ethynyl, 2-(2,2-dicyanovinyl)-thiophen-5-yl-ethynyl, 4-nitrophenylethynyl, 6-nitrobenzothiazol-2-yl-ethynyl, or 5-nitrothiazol-2-yl-ethynyl are reported. The dynamic hyperpolarizabilities of these compounds were determined from hyper-Rayleigh light scattering measurements carried out at a fundamental incident irradiation wavelength (lambda(inc)) of 1300 nm; these measured beta(1300) values ranged from 690 -> 1400 x 10(-30) esu. These data (i) show that these neutral dipolar molecules express substantial beta(1300) values, (ii) highlight that reductions in the magnitude of the aromatic stabilization energy of (porphinato) metal-pendant arylethynyl groups have a significant impact upon the magnitude of the molecular hyperpolarizability, and (iii) provide insights into advantageous design modifications for closely related structures having potential utility in long-wavelength electrooptic applications.