Effects of a central metal on the organization of 5,10,15,20-tetra-(p-chlorophenyl)–rare earth porphyrin hydroxyl compound at the air/water interface and in Langmuir–Blodgett films

Li, Xiaoling; Xu, Weiqing; Itoh, Tamitake; Ikehata, Akifumi; Zhao, Bing; Li, Bofu; Ozaki, Yukihiro

doi:10.1016/j.jcis.2004.10.053

Cited by 9 publications

(19 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These porphyrins yield isotherms with an extrapolated area of only 13-17 Å 2 per molecule 1 . This contrasts with an expected value of 225 Å 2 per molecule, if the molecules lie flat on the water surface, and with an expected value of 90 Å 2 per molecule for a vertical packing array of molecules 2 . For these macrocyclic molecules, organized supramolecular structures can be formed in monolayers.…”

Section: Introductioncontrasting

confidence: 62%

“…These structures, referred to as a playing-card model, have been confirmed by AFM measurements of Langmuir and self-assembled monolayers of porphyrins and phthalocyanines 2 . The substantial attractive π-π interaction between porphyrin macrocycles may cause significant pre-aggregation prior to the compression of the film forming domains 2,3 . Furthermore, the limitation of 3D conformation due to the planar structure restricts the overall mobility on reaching a thermodynamic energy minimum.…”

Section: Introductionmentioning

confidence: 70%

“…Such is the case in Langmuir-Blodgett (LB) monolayers and self-assembled monolayers (SAM), in which the macrocycles arrange themselves in a parallel alignment due to the inherent organization of the macrocyclic rings. The presence of double-conjugated bonds attributes the sp 2 planar configuration with several possibilities of π-π* transitions. These structures, referred to as a playing-card model, have been confirmed by AFM measurements of Langmuir and self-assembled monolayers of porphyrins and phthalocyanines 2 .…”

Section: Introductionmentioning

confidence: 99%

“…The presence of double-conjugated bonds attributes the sp 2 planar configuration with several possibilities of π-π* transitions. These structures, referred to as a playing-card model, have been confirmed by AFM measurements of Langmuir and self-assembled monolayers of porphyrins and phthalocyanines 2 . The substantial attractive π-π interaction between porphyrin macrocycles may cause significant pre-aggregation prior to the compression of the film forming domains 2,3 .…”

Section: Introductionmentioning

confidence: 99%

“…Based on the lower than expected area/molecule values, it can be concluded that in general the material must form multilayer stacks in which the structure and stability of the film (collapse 40 mNm -1 ) is governed mainly by molecular packing rather than by hydrophilic/ hydrophobic interactions [1][2][3]7 .The exposure of porphyrins to oxidizing or strong reducing gases induce dramatic change in the UV-visible absorption spectrum (Soret and Q bands) that are associated with π → π* transitions and provide the basis for a remarkably interesting gas sensing capability 8,9 . The organization of supramolecular assemblies of H 2 TPP films and its derivatives are dependent of subphase temperature and subphase modifications [2][3]7 , such as the addition of different electrolytes 7 or changes in pH 10 .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Chemsensor of NO2 gas based on porphyrin of 5, 10, 15, 20-tetraphenylporphyrin LB films and LS films

Sales

Mansur

2008

Mat. Res.

View full text Add to dashboard Cite

The sensitivity of 5, 10, 15, 20-tetraphenylporphyrin (H 2 TPP) to the presence of NO 2 gas in diluted solutions and in Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) films was investigated by UV-visible spectroscopy. The shift of Soret and Q bands were analyzed and the energies involved were calculated. The exposure of LB porphyrin films deposited onto glass slides to NO 2 has performed as an active chemsensor with 7000 ppm gas concentration. Furthermore, the UV-vis dichroism absorption results associated with the Soret bands have given evidence of the tilt angle of the macrocycle related to the substrate. H 2 TPP in LB film was tilted by an angle of 51 ± 5° and in the LS film was tilted by an angle of 36° ± 5° indicating the formation of a preferential organization of the molecular films depending on the deposition method.

show abstract

Section: Introductioncontrasting

confidence: 62%

Section: Introductionmentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Chemsensor of NO2 gas based on porphyrin of 5, 10, 15, 20-tetraphenylporphyrin LB films and LS films

Sales

Mansur

2008

Mat. Res.

View full text Add to dashboard Cite

show abstract

Synthesis, Aggregation and Cellular Investigations of Porphyrin–Cobaltacarborane Conjugates

Hao

Sibrian‐Vazquez

Serem

et al. 2007

Chemistry A European J

View full text Add to dashboard Cite

A new series of porphyrin-cobaltacarborane conjugates (1-5) that contain four to sixteen carborane clusters per porphyrin macrocycle, were prepared in excellent yields (90-97 %) by means of a ring-opening reaction of the zwitterionic cobaltacarborane [3,3'-Co(8-C(4)H(8)O(2-)-1,2-C(2)B(9)H(10))(1',2'-C(2)B(9)H(11))]. The X-ray structure of one conjugate (3) is presented. The aggregation properties of these conjugates were investigated by using absorption and fluorescence spectrophotometry, and the stages of microcrystal formation were captured by using atomic force microscopy. All conjugates were found to aggregate in aqueous solutions, to form a broad dispersity of particle sizes. The cellular uptake, cytotoxicity, and preferential sites of subcellular localization of this series of conjugates were evaluated in human carcinoma HEp2 cells. The extent of conjugate cellular uptake depends on the number of cobaltacarborane units at the porphyrin periphery, their distribution, and the conjugate aggregation behavior. Conjugates 2 and 4, bearing either two adjacent or three 3,5-dicobaltacarboranephenyl groups, accumulated the most within HEp2 cells and are, therefore, the most promising boron neutron capture therapy agents. All conjugates showed very low dark- and photo-toxicity, probably due to their strong tendency for aggregation in aqueous solutions, and localized subcellularly within vesicles that correlated, to some extent, with the cell lysosomes.

show abstract

Preparation and characterization of 5,10,15,20‐tetraphenylporphyrin Langmuir films for gas chemsensor applications

Mansur

Sales

2011

Surface & Interface Analysis

View full text Add to dashboard Cite

In this work is reported the preparation and characterization of 5,10,15,20-tetraphenylporphyrin (H 2 TPP) films at the water-air interfaces. The surface pressure-area isotherms (π -A) and UV-Vis spectroscopy were used to investigate the effect of the spreading methods and parameters on the porphyrin monolayer formation. Also, Langmuir-Blodgett (LB) and LangmuirSchaefer (LS) films were deposited onto glass substrates in order to study the conformation changes in porphyrin molecular packing. Quartz crystal microbalance (QCM) was utilized as the active solid substrate for the development of the NO 2 gas sensor based on the H 2 TPP molecular films. The results of π -A curves have clearly shown the significant contribution of the preparation methods and processing parameters on the conformation of porphyrin molecular films. The UV-Vis spectroscopy results using polarized absorption dichroism have indicated different molecular packing for porphyrin films deposited by LB and LS methods, with relative tilted angles of 50• ± 5• and 35• ± 5 • , respectively. Moreover, the QCM response has given strong evidence that H 2 TPP porphyrin molecular films have performed as NO 2 chemsensor.

show abstract

Effects of a central metal on the organization of 5,10,15,20-tetra-(p-chlorophenyl)–rare earth porphyrin hydroxyl compound at the air/water interface and in Langmuir–Blodgett films

Cited by 9 publications

References 47 publications

Chemsensor of NO2 gas based on porphyrin of 5, 10, 15, 20-tetraphenylporphyrin LB films and LS films

Chemsensor of NO2 gas based on porphyrin of 5, 10, 15, 20-tetraphenylporphyrin LB films and LS films

Synthesis, Aggregation and Cellular Investigations of Porphyrin–Cobaltacarborane Conjugates

Preparation and characterization of 5,10,15,20‐tetraphenylporphyrin Langmuir films for gas chemsensor applications

Contact Info

Product

Resources

About