Design, Synthesis, Linear, and Nonlinear Optical Properties of Conjugated (Porphinato)zinc(II)-Based Donor−Acceptor Chromophores Featuring Nitrothiophenyl and Nitrooligothiophenyl Electron-Accepting Moieties

Abstract

An extensive series of conjugated (porphinato)zinc(II)-based chromophores featuring nitrothiophenyl and nitrooligothiophenyl electron-accepting moieties has been synthesized using metal-catalyzed cross-coupling reactions involving [5-bromo-15-triisopropylsilylethynyl-10,20-diarylporphinato]zinc(II) and an unusual electron-rich Suzuki-porphyrin synthon, [5-(4-dimethylaminophenylethynyl)-15-(4',4',5',5'-tetramethyl[1',3',2']dioxaborolan-2'-yl)-10,20-diarylporphinato]zinc(II), with appropriately functionalized aryl and thienyl precursors. These donor-acceptor chromophores feature thiophenyl, [2,2']bithiophenyl, and [2,2';5',2' ']terthiophenyl units terminated with a 5-nitro group; one series of structures features these acceptor moieties appended directly to the porphyrin macrocycle meso-carbon position, while a second set utilizes an intervening meso-ethynyl moiety to modify porphyrin-to-thiophene conjugation. The dynamic hyperpolarizability of these compounds was determined from hyper-Rayleigh light scattering (HRS) measurements carried out at fundamental incident irradiation wavelengths (lambda(inc)) of 800 and 1300 nm; interestingly, measured beta(1300) values ranged from 650 --> 4350 x 10(-30) esu. The combined linear and nonlinear optical properties of these compounds challenge the classical concept of the nonlinearity/transparency tradeoff in charge-transfer chromophores: the magnitude of the molecular hyperpolarizability is observed to vary substantially despite approximately uniform ground-state absorptive signatures for a given porphyrin-to-thiophene linkage topology. These data show that these neutral dipolar molecules can express substantial beta(1300) values; such conjugated, electronically asymmetric porphyrin-thiophene chromophores may thus find utility for electrooptic applications at telecom-relevant wavelengths.

Porphyrins for Probing Electrical Potential Across Lipid Bilayer Membranes by Second Harmonic Generation

“…[45][46][47][48][49][50][51] Conjugated porphyrin dimers exhibit much larger third-order susceptibilities (g) than the corresponding porphyrin monomers, [49][50][51] thus Equation (3) implies that dimeric analogues of JR1 will display even higher sensitivities to electric field. Previous studies on voltagesensitive SHG dyes have focused entirely on styryl and retinal chromophores.…”

Theoretical Investigation on the One‐ and Two‐photon Absorption Properties of Porphyrin‐thiophene Chromophores

“…The results accord with experimental values. 25 In PT and PET series, the position of Soret band shifts to red direction with the number of thiophene rings increasing. In addition, the O max λ value of PT series is smaller than that of PET series with the same number of thiophene units in Soret band and Q band.…”

“…ZnP, which possesses D 4h symmetry, was established by the computed and experimental IR results. In the experimental report, 25 3,5-bis(3,3-dimethylbutyloxy)-phenyl groups were at the meso-positions of porphyrin ring. But, in our calculation, 3,5-bis(3,3-dimethylbutyoxy)phenyl groups were replaced by phenyl groups in order to save the calculating time.…”

“…But, in our calculation, 3,5-bis(3,3-dimethylbutyoxy)phenyl groups were replaced by phenyl groups in order to save the calculating time. Table 2 lists the calculated OPA wavelength O max λ , the corresponding experimental 25,30 and theoretical values in literature 30 (given in parentheses), as well as the oscillator strength Figure 2 Total density of states (DOS) of P, PT series and PET series.…”

“…24 The chromophores were synthesized by Zhang et al 25 In this paper, we theoretically study equilibrium geometries, electronic structures, OPA and TPA properties of conjugated porphyrin-thiophene chromophores.…”