Photon-gated persistent spectral hole burning by donor-acceptor electron transfer in tetraphenylporphine/halogenated anthracene systems

Abstract

Photon-gated persistent spectral hole burning was observed for metal-free tetraphenylporphine with halogenated anthracene derivatives in poly(methylmethacrylate) or poly(ethylene) at liquid-helium temperatures. The hole formation yield was markedly dependent on the polymer matrices and the sample composition as well as on the gating wavelength. The irreversible broadening of holes in the systems measured by temperature cycling experiment was smaller than that by proton tautomerization of tetraphenylporphine. We concluded that the hole formation mechanism is donor-acceptor electron transfer on the basis of combined analysis of the matix and acceptor concentration dependence of hole formation yield, the action spectrum of the gating photon and the photoproduct spectrum.

Spectroscopy, persistent hole burning, and holographic applications of naphtophthalocyanine/haloanthracene systems

“…In contrast to the results in [1], and in correspondence with the observations in [2], the long living IS is not likely the triplet state of H 2 -TBNP, since in general phthalocyanines have a much shorter triplet state lifetime of the order of 1 ms [8]. An unusual feature of the observed gated holes is their small width of about 400 MHz, which is close to that for nongated materials, and about 10-20 times less than typically observed in other gated PSHB materials [1][2][3][4]. The reason for such narrow holes is likely related to a relatively low concentration of acceptor molecules 1-ClA of about 10 À4 mol/l due to the lesser influence of the electric field induced by D-A pair formation [1].…”

“…Based on the results of the study of gated hole burning for porpyrins in the presence of halogenated aromatic compounds [1][2][3], we propose the following two-photon gating mechanism in our case. It involves the selective excitation by the l 1 -photon of H 2 -TBNP (donor, D); electron transfer reaction in the excited (likely triplet) states of donor to 1-ACl (acceptor, A) through the intermediate state (IS); and the induced l 2 -photon formation of a stable photo-product SP,…”

“…Many of these materials exhibit photon-gated two-photon PSHB mechanisms [1][2][3][4], which permit nondestructive one-photon readout. In addition, some of these systems have high hole burning efficiency and allow fast single shot hole burning in the nanosecond [1] and even the picosecond [3] time scale.…”

A New Persistent Photon‐Gated Spectral Hole‐Burning System:Zinc Tetraphenylporphyrin Linked to Polyvinylbenzylchloride‐Co‐Polystyrene

“…They discussed their result assuming the guest molecules are mainly located in the amorphous parts of the semicrystalline PE matrix, giving rise to a D-A average separation in PE shorter than in complete amorphous PMMA. 26 In our case, we understand the negative result in the PS host as a consequence of the non-polar character of polystyrene. Due to the weakness of the polarity of the PS host, the electron transfer can not be stabilized, even at the liquid helium temperature.…”

Analysis of the structure (XRD) and microstructure (TEM, SEM, AFM) of bulk amorphous and nanocrystalline alloys based on FeCoB

“…As Inoue et al stated, the difference in the atomic radii (in particular, between the main elements of the alloy) should be greater than 12 %. In addition, the investigated alloy consists of more than three elements, which fulfils the second of the aforementioned bulk amorphous alloy criteria, published by Inoue et al It is well known that the addition of the element Cu hinders the growth of crystalline grains and therefore favours the creation of a nano-crystalline structure [15]. The elements Be and Cr were added in order to improve the mechanical properties and corrosion resistance.…”