Dye porphyrins

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). 

Fig. 18.9 Left part - device performance as a function of soaking time for Ti02-based devices using nanographene/porphyrin hybrids (closed) and porphyrin dyes (open). Right part - device performance as a function of soaking time for ZnO-based devices using nanographene/porphycene hybrids (closed) and porphycenes (open).

For formation of two porphyrin dye layers face-to-face on the support, the slide was simply dipped and then removed through the porphyrin film on the subphase. Deposition of surfactant porphyrins on the SnC OTE s for the photoelectric measurements was by vertical removal of the OTE (two slides at a time with the glass surfaces facing each other) through the porphyrin mixture on the aqueous subphase. Surfactant porphyrin (MT0APP) stearic acid octadecane monolayers in the ratio of 1 4 3 were held at a constant pressure of 25 dyne/cm for these depositions. 

The sensitization properties of porphyrin compounds have also been improved by introducing dendron groups to the cyano substituted meso-stilbene moieties (46, 47). The aggregation of porphyrin was efficiently suppressed by the bulky dendrons while the electron injection to the conduction band of TiC>2 was improved by the cyano groups. The overall energy transfer efficiency was promoted remarkably to 2.76% for a solid DSSC. This is an encouraging result for a porphyrin dye and it offers the potential for porphyrins as alternatives to ruthenium-based dyes in the DSSC [82]. 

Odobel F., Blart E. Lagree, M. Villieras, M. Boujtita, H. El Murr N., Caramori S. and Alberto Bignozzi C. (2003), Porphyrin dyes for Ti02 sensitization , /. Mat. Chem. 13, 502-510. 

The structure of donor-acceptor porphyrin complexes such as 68 has very recently been modified to make a new family of amphiphilic porphyrin dyes with polar pyridinium acceptor head groups and hydrophobic dialkyl-aniline donors (Figure 1.34). The free porphyrins and... 

Identification and Assignment of Structure The identity of a synthetic product is often established by comparison of its absorption curve with that of the natural product or another standard sample. The absorption curves of synthetic and natural vitamin A2 are shown in Figure 7.1. The identification pf coloured substances is easier since colour can almost always be correlated with the presence of certain types of chromo-phoric groups. Thus, visible absorption spectra are employed for the detection and identification of the natural pigments (e.g. carotenoids, anthocyanins md porphyrins), dyes and other colouring matters. Hie absorption spectra of these colouring principles will be discussed separately in Chapter 12. 

The porphyrin dyes hemoglobinen and chlorophyll are biologically important. Both are octahedral metal complexes, the proteins being bound to the central atom. In the hemoglobin molecule there are five ligand positions occupied by histidine. 

Figure 13.95. Porphyrin dyes for sensitizing composite films.

Barooah, N. Bhasikuttan, A. C. Sudarsan, V. Choudhury, S. D. Pal, H. Mohanty, J. Surface functionalized silver nanoparticle conjugates demonstration of uptake and release of a phototherapeutic porphyrin dye. Chem. Comm. 2011,47, 9182-9184. 

Amao Y (2003) Probes and polymers for optical sensing of oxygen. Mikrochim Acta 143 1-12 Amao Y, Nakamura N (2004) Optical CO2 sensor with the combination of colorimetric change of a-naphtholphthalein and internal reference fluorescent porphyrin dye. Sens Actuators B 100 347-351 Ando M, Kobayashi T, Haruta M (1994) Enhancement in the optical CO sensitivity of NiO film by the deposition of ultrafine gold particles. J Chem Soc Faraday Trans 90 1011-1013 Ando M, Kobayashi T, Haruta M (1995) Optical CO detection by use of CuO/Au composite films. Sens Actuators B 24-25 851-853... 

In our initial studies on the simultaneous use of multiple dyes, we utilized the porphyrin dye, TSPP, in eombination with HPTS. Both of these dyes can be exeited at 414 nm. In this two-dye study, we decided to use as the boronic aeid reeeptor/queneher eomponent. When the two-dye solution was treated with m-BBV, the emission of both dyes was readily quenehed to similar levels. When this quenched solution was titrated with glucose, both emission peaks showed a strong fluorescence increase. We decided that we could exploit the use of multiple dyes further by including a non-responsive reference dye into the configuration to provide a ratiometric sensing system. 

The DSSC is one of the most-studied types of emerging SCs. Initially, ruthenium dyes were used. Then, porphyrin dyes found widespread application in DSSCs because of their favorable optical properties and chemical bond flexibility. Efficiency of these DSSCs was not much impressive until mid-2000. Progress in a molecular design and synthesis of new porphyrins as well as preparation of new more efficient charge mediators allowed improving this efficiency dramatically. This improvement was mostly due to introduction of the push-pull structured and 71-extended peripheral substituents. The recent research focuses on enriching absorbance spectra of MPs. It resulted in efficiency of DSSCs with MPs equal to those with the ruthenium dyes. 

A large variety of porphyrin peripheral substituents was proposed in multiple efforts of increasing the DSSC efficiency, which resulted in an impressive progress over last decade. The PCE of the latest top-performing DSSCs with the porphyrin dyes is 12 % and, in some cases, as high as 13 % for the SM315 porphyrin (Scheme 8) [9]. 

Scheme 8 Stmctural formulas of examples of porphyrin dyes high-performing in DSSCs along with their PCE and year of invention, vis., SM315, [9] YD-2, [10] YDDl a meso-meso porphyrin dimer, and YDD2-fused porphyrin [11]...

Initially, heteroatomic anchoring groups were introduced for non-porphyrin dyes [14]. Only afterwards, these groups were introduced for porphyrins. A series of ZnPs with different numbers of anchoring groups at me o-positions [47] and one with the phenyl spacer in the A group [48] were synthesized and applied to DSSC (Scheme 26). 

Ju M-G, Liang W (2013) Computational insight on the working principles of zinc porphyrin dye-sensitized solar cells. J Phys (Them C 117(29) 14899-14911... 

Daphnomili D, Landrou G, Prakash Singh S et al (2012) Photophysical, electrochemical and photovoltaic properties of dye sensitized solar cells using a series of pyridyl functionalized porphyrin dyes. RSC Adv 2(33) 12899-12908... 

Seo KD, Lee MJ, Song HM et al (2012) Novel D-a-A system based on zinc porphyrin dyes for dye-sensitized solar cells synthesis, electrochemical, and photovoltaic properties. Dyes Pigm 94(1) 143-149... 

Kang MS, Kang SH, Kim SG et al (2012) Novel D-a-A stmctured Zn(II)-porphyrin dyes containing a bis(3,3-dimethyllluorenyl)amine moiety for dye-sensitised solar cells. Chem Commun 48(75) 9349-9351... 

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