Outstanding Quadratic to Septic Optical Nonlinearity at Dipolar Alkynylmetal‐Porphyrin Hybrids

Porphyrins are important macrocycles with applications in several areas including therapy, catalysis, and sensing. Strong nonlinear optical (NLO) responses the key to fully exploiting potential of these biocompatible molecules. We herein report that certain metal-alkynyl donor/nitro acceptor-functionalized porphyrins attractive candidates for NLO applications. show specific examples exhibit record quadratic nonlinearity, exceptional two-photon absorption, outstanding three-photon we first four-photon absorption. The two-, three-, absorption maxima found at corresponding multiples linear bands time-dependent density functional theory assigns as admixtures porphyrin-localized π*←π donor-porphyrin porphyrin-acceptor charge-transfer transitions.