Spatial Resolution and Data Addressing of Frequency Domain Optical Storage Materials in the Near IR Regime

Ao, R.; Jahn, S.; Kümmerl, L.; Weiner, Robert; Haarer, D.

doi:10.1143/jjap.31.693

Cited by 23 publications

(2 citation statements)

References 8 publications

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“…The photoinduced proton-transfer (PIPT) reaction of 2-(2‘,4‘-dinitrobenzyl)pyridine (DNBP), which has already been known for 70 years, has attracted special attention in recent times. − Systems of this kind that undergo a proton-transfer reaction to produce a long-lived species may represent the basis for optical switches in optical data processing and data-storage applications − and for the development of molecular protonic devices …”

Section: Introductionmentioning

confidence: 99%

Quantum Chemical Investigations of the Thermal and Photoinduced Proton-Transfer Reactions of 2-(2‘,4‘-Dinitrobenzyl)pyridine

Frank¹,

Peyerimhoff²

1996

J. Phys. Chem.

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Quantum chemical calculations of the proton-transfer system 2-(2‘,4‘-dinitrobenzyl)pyridine (DNBP) and of derivatives with larger aromatic bases are presented. These systems undergo photochemical isomerizations from a stable form to two different photoisomers. Ab initio methods are employed to investigate the isomerization of methylimine to vinylamine as a model system for the proton-transfer reaction of DNBP. The ground and excited states of both isomers and of the transition state for the isomerization are studied with Hartree−Fock and MRD-CI (multireference singles and doubles CI) methods. The isomerizations of the larger system DNBP and its derivatives are investigated with semiempirical PM3-SCF and PM3-MRD-CI methods. The intrinsic reaction coordinate formalism is used for calculating the reaction pathways from the optimized transition states. The relative stabilities of the various isomers and the mechanism of the intramolecular proton-transfer reaction are discussed. The ortho-nitro group assists the proton transfer from the methylene group to the pyridine ring. The experimentally observed reaction barriers are reproduced by taking crystal effects into account.

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Section: Introductionmentioning

confidence: 99%

Quantum Chemical Investigations of the Thermal and Photoinduced Proton-Transfer Reactions of 2-(2‘,4‘-Dinitrobenzyl)pyridine

Frank¹,

Peyerimhoff²

1996

J. Phys. Chem.

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“…[2][3][4][5] Optical switches are of great interest for optical data processing and optical data storage. [6][7][8][9][10] In order to form the basis for the preparation of optical switches, a system should exhibit bistability, i.e., it should exist in two thermally sufficiently stable states that can be selectively and reversibly converted into each other by irradiation. In the case of DNBP the thermal back reaction occurs within 5 days, which is too fast for most applications.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Molecular Dynamics Study of a Photochromic Molecular Crystal

1999

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We present first-principles calculations for the thermal reaction in the photochromic molecular crystals of 2-(2′,4′-dinitrobenzyl)-pyridine (DNBP). Under irradiation this dye molecule undergoes a characteristic change of color as a result of an intramolecular proton-transfer reaction. By simulating the thermal reaction with first-principles molecular dynamics, we show that during the thermal proton transfer a hydrogen bond from the o-nitro group to the migrating proton is formed intermediately, which serves as a "bridge" between the educt and product forms. Furthermore, we present the experimentally not accessible structures of the crystalline photoisomers. On the basis of our results we conclude that photoisomerization is possible in the crystalline phase. This property is of elementary interest for technical applications of this system.

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Information Storage Materials, Optical

Kämpf¹,

Mergel²

2000

Kirk-Othmer Encyclopedia of Chemical Technology

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In addition to the established magnetic mass storage media (floppy disk, hard disk, tape) optical mass storage media (CD‐ROM (compact disk‐read only memory), WORM (write once, read many times), EOD (erasable optical disk)) are increasingly used. Generally, magnetic and optical media do not compete, but complement each other due to their specific advantages. Progress in optical data storage technology is closely connected with the development of suitable materials. This article illustrates in detail the current state of the art and the ongoing development of materials for optical data storage. For the information layer of WORM disks, dyes with high ir absorption, low heat conductivity, and good solubility are required. Besides polymethine dyes, biaxially substituted silicon–naphthalocyanines are used; also combinations of metal complexes are employed. The magneto‐optical materials for EOD‐disks in MOR (magneto‐optical recording) technique are primarily ferrimagnetic ternary amorphous alloys of rare‐earth (RE) and transition‐metals (TM) (GdTbFe, TbFeCo, DyFeCo). Ferrites with spinel‐ or garnet‐structure, eg, rare‐earth iron‐garnets (RIG), are commercially unimportant mainly due to their high deposition temperature. Co/Pt‐multilayers (MLs) exhibit interesting properties, but are still waiting for commercial introduction. Research concentrates on exchange‐coupled RE‐TM layers, which permit a direct overwrite procedure. Phase‐change materials for EOD‐disks in PCR (phase‐change recording) technique are primarily ternary alloys (eg, GeSbTe, InSbTe). Research focuses on materials with fast crystallization in parallel with high stability even at numerous write/read/erase cycles. As substrate materials for CD‐ROM disks, end group‐modified bisphenol A–polycarbonate (BPA‐PC) is employed exclusively. For WORM and EOD disks mainly BPA‐PC and sometimes glass is applied.

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Spatial Resolution and Data Addressing of Frequency Domain Optical Storage Materials in the Near IR Regime

Cited by 23 publications

References 8 publications

Quantum Chemical Investigations of the Thermal and Photoinduced Proton-Transfer Reactions of 2-(2‘,4‘-Dinitrobenzyl)pyridine

Quantum Chemical Investigations of the Thermal and Photoinduced Proton-Transfer Reactions of 2-(2‘,4‘-Dinitrobenzyl)pyridine

First-Principles Molecular Dynamics Study of a Photochromic Molecular Crystal

Information Storage Materials, Optical

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