Nonlinear optical properties porphyrins

For the description of the linear and nonlinear optical properties of metallotetrapyrroles, TDDFT methods have proven [133-148] to be an excellent alternative to conventional highly correlated ab initio methods, such as SAC-CI, STEOM-CC, and CASPT2, for which these systems still represent a severe computational challenge, especially when transition metals, lanthanides or actinides are involved. The few highly correlated ab initio calculations dealing with the excited state properties of metallotetrapyrroles that have appeared to date only concern magnesium and zinc porphyrins and porphyrazines [149-151]. Application of TDDFT methods to the electronic spectroscopy of a variety of metallotetrapyrroles, including homoleptic and heteroleptic sandwiches, will be illustrated in this section. 

Both quantum functional materials and molecular devices are considered to be the ultimate functional materials. The former shows a novel property which is specific to the structure and the latter represents the smallest possible functional material. Their properties are closely related to optical and photonic functions. The former shows a quantum size effect, a photoluminescence shift to higher energy which depends on layer thickness, which gives us an idea of a nonlinear optical system. Porphyrin arrays connected with molecular wires show a hole carrier photoconductivity or a photoswitching and a photo-information storage, which suggests an idea of a photoactive neuron model. In this paper, conjugated polymer superlattices and porphyrin arrays connected with molecular wires are described. 

One photorefractive polyimide 59 was formed by linking thee units, a substituted porphyrin (charge generator), 4-amino-4 -nitrostilbene derivative (the nonlinear optics molecule), and a charge transporting agent, pyromellitic dianhydride. This polyimide retains its nonlinear optical properties even after... 

The brief presents a systematic study of synthesis of optically active polymers. It discusses in detail about the syntheses of three different types of optically active polymers from helical polymers, dendronized polymers and other types of polymeric compounds. The brief also explains the syntheses of optically active azoaromatic and carbazole containing azoaromatic polymers and copolymers optically active benzodithiophene and optically active porphyrin derivatives. The final chapter of the brief discusses different properties of optically active polymers such as nonlinear optical properties, chiroptical properties, vapochromic behavior, absorption and emission properties, fabrication and photochromic properties. The intrinsic details of different properties of optically active polymers will be useful for researchers and industry personnel, who are actively engaged in application oriented investigations. 

J. Lu, L. Wu, L. Jing, X. Xu, X. Zhang, Synthesis, circular dichroism and third-mrder nonlinear optical properties of optically active porphyrin derivatives beating four chiral citronellal moieties. Dyes Pigm. 94, 169-174 (2012)... 

The structure(Zn,Ph)-property(a,/ ,7,) relationship has been investigated in this work by semiempirical PM3 and PM6 methods. The ZnTPP-(C)4-[60] dyad was found to exhibit large values of second hyperpolarizability. We found almost linear correlation between the size of the conjugated polyalkynyl linkage and the optical properties of the whole fullerene-porphyrin dyad. As a part of the present study, we have found that the nonlinear optical properties of model donor-substimted [60]fullerene derivatives are poorly described by the BLYP functional. The long-range corrected LC-BLYP functional, on the other hand, successfully cures the overshoot problem both for / and 7. The calculations for A-methylfulleropyrrolidine shows that the linear absorption spectra is reproduced quite well by conventional PBEO and B3LYP functionals. 

Nonlinear optical organic materials such as porphyrins, dyes, and phthalocyanines provide optical limiting properties for photonic devices to control light frequency and intensity in a predictable manner. The optical limit of CNTs composites is saturated at CNTs exceeding 3.8wt% relative to the polymer mass (Chen et al., 2002). Polymer/ CNT composites could also be used to protect human eyes, for example, optical elements, optical sensors, and optical switching (Cao et al., 2002). 

As with phthalocyanines, the third-order nonlinear optical susceptibility, of porphyrins can be manipulated by chemical substitution. The third-order NLO properties of several tetraphenylporphyrin compounds were first reported by Meloney et The was measured by the degenerate four-wave mixing (DFWM) technique from... 

Goals and objectives of the study. Objective to establish a relationship between the optical and magnetic properties, systematic scientific analysis of the nature of the interaction of metals with fullerenes, the smdy of nonlinear optical effects of porphyrins, fullerenes and carbon nanostrucmres. 

Scientific novelty of the results The most significant new scientific results of the study are established the linear and nonlinear optical (NLO) properties of porphyrins derivatives and fuUerene carbon nanostructures. 

Fullerene-Doped Polyvinylcarbazole. Fullerenes are known to be good electron acceptors. In the presence of electron donors such as aromatic amines, weakly bonded charge-transfer complexes can be formed [115]. Through virtual excitation, the existence of charge-transfer interaction can enhance the second-order optical nonlinearity of fullerenes [116], With direct excitation, excited state electron transfer between fullerenes and various electron donors such as aromatic amines [115,117], semiconductor colloids [118], porphyrin [119], and polymers [101, 103, 120] can occur. This electron-accepting property led to the development of fullerene-doped polymeric photoconductors [101,103]. 

Although metallophthalocyanines have been studied in detail, there are few reports on optical limiting properties of porphyrins. Blau et showed reverse saturable absorption (RSA) by cobalt and zinc TPP complexes. Fei et reported RSA in Fe(TPP). Nonlinear excited state absorption in a series of metallotexaphyrin compounds (Figure 37)... 

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