Metalloporphyrins self-assembled films

SERS Studies on Metalloporphyrin Self-Assembled Films on Organic-Monolayer-Modified Substrates... 

Most studies of ORR catalysis by metalloporphyrins have been carried out using water-insoluble catalysts absorbed on a graphite electrode in contact with aqueous solution. In a limited number of cases, four other approaches have been used catalysts imbedded in an inert film (i.e., Nafion or lipid) on the electrode surface self-assembled monolayers of catalysts catalysts in aqueous or mixed organic/aqueous solutions in contact with an electrode and catalysis in mixed aqueous/organic medium using... 

Relatively little work has been done on ORR catalysis by self-assembled mono-layers (SAMs) of metalloporphyrins. The advantages of this approach include a much better defined morphology, structure, and composition of the catalytic film, and the surface coverage, and the capacity to control the rate at which the electrons ate transferred from the electrode to the catalysts [CoUman et al., 2007b Hutchison et al., 1993]. These attributes are important for deriving the catal5d ic mechatfism. The use of optically transparent electrodes aUows characterization of the chemical... 

Porphyrin-based self-assembled molecular squares 389 can form mesoporous thin films in which the edge of a square, thus the size of the cavity, can be adjusted by appropriate choice of substituents [8]. Fibers that form coil-coiled aggregates with distinct, tunable helicity are built from crown ethers bearing porphyrins 390 [9]. In addition to the porphyrin applications discussed in Sections 6.3.2.2 and 6.4, dendrimer metalloporphyrins 391 to be applied in catalysis [10] and the water-soluble dendritic iron porphyrin 319 modelling globular heme proteins [11] can be mentioned. 

Self-assembled monolayers have recently attracted much attention as a new methodology for molecular assembly [249, 342]. They enable highly organized chemical binding of molecules of interest to the surfaces of, e.g., metals, semiconductors, and insulators. The well-ordered structure of self-assembled monolayers is in sharp contrast with conventional Langmuir-Blodgett films and lipid bilayer membranes in terms of stability, uniformity, and manipulation. Functional molecules can be arranged unidirectionally at the molecular level on substrates when substituents which will self-assemble on the substrates are attached to a terminal of the molecules. The wide variety of examples reported to date include porphyrins and metalloporphyrins in self-assembled monolayers [299-339]. 

Kalyuzhny G, Vaskevick A, Ashkenasy G, Shanzer A (2000) UV/Vis spectroscopy of metalloporphyrin and metallophthalocyanine monolayers self-assembled on ultrathin gold films. J Phys Chem B 104 8238-8344... 

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