Characterization of New Excimer Pumped UV Laser Dyes 3.P‐Quinqui‐, Sexi‐, Octi‐ and Deciphenyls

Seliskar, Carl J.; Landis, David A.; Kauffman, Joel M.; Aziz, Mohammed Abdul; Steppel, Richard N.; Kelley, Charles J.; Qin, Yuanxi; Ghiorghis, Alem

doi:10.1155/1993/52165

Cited by 15 publications

(15 citation statements)

References 7 publications

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“…Another coupling, catalyzed by PdCl 2 ∑dppb, that of excess phenylmagnesium bromide with 10, gave white DMSP in 70% yield, which was homogeneous on TLC. Both the UV maximum wavelength and the epsilon fit the relationships worked out by Seliskar 13,14 for p-oligophenylenes, supporting the structure. The 1 H NMR spectrum showed the expected ratio of 6 methyl protons to 24 aromatic protons.…”

Section: Methodssupporting

confidence: 75%

A Really Convenient Synthesis of 2′,3″′-Dimethyl-p-sexiphenyl

Kauffman¹

1999

Synthesis

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Modern cross-couplings of arylmagnesium bromides with dibromoarenes gave 3,3'''-dimethylquaterphenyl and, from its dibromination product, 2',3''''-dimethyl-p-sexiphenyl (DMSP) in high yield with use of the air-stable PdCl 2 ∑dppb in catalytic amount. Arylboronic acids need not be prepared as intermediates, and use of pyrophoric aryllithiums was avoided. DMSP is a useful scintillation fluor with high stability and fast response time.

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Section: Methodssupporting

confidence: 75%

A Really Convenient Synthesis of 2′,3″′-Dimethyl-p-sexiphenyl

Kauffman¹

1999

Synthesis

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“…Linear and recently reported cyclic oligo- p -phenyls with and without methyl and t -butyl substituents are among the simplest extended π -electron systems ( Chart 4 ). Linear oligo- p -phenyls have been utilized as luminophores in dye lasers and scintillators in near-UV and visible region for many years [ 76 , 77 , 78 ] due to their photochemically and thermally robust features. Although unsubstituted oligo- p -phenyls longer than five or six repeating units have limited solubility, p -dioxane is commonly used as a solvent for reasons not fully understood by the authors.…”

Section: Resultsmentioning

confidence: 99%

Questions of Mirror Symmetry at the Photoexcited and Ground States of Non-Rigid Luminophores Raised by Circularly Polarized Luminescence and Circular Dichroism Spectroscopy: Part 1. Oligofluorenes, Oligophenylenes, Binaphthyls and Fused Aromatics

et al. 2018

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We report experimental tests of whether non-rigid, π-conjugated luminophores in the photoexcited (S1) and ground (S0) states dissolved in achiral liquids are mirror symmetrical by means of circularly polarized luminescence (CPL) and circular dichroism (CD) spectroscopy. Herein, we chose ten oligofluorenes, eleven linear/cyclic oligo-p-arylenes, three binaphthyls and five fused aromatics, substituted with alkyl, alkoxy, phenyl and phenylethynyl groups and also with no substituents. Without exception, all these non-rigid luminophores showed negative-sign CPL signals in the UV-visible region, suggesting temporal generation of energetically non-equivalent non-mirror image structures as far-from equilibrium open-flow systems at the S1 state. For comparison, unsubstituted naphthalene, anthracene, tetracene and pyrene, which are achiral, rigid, planar luminophores, did not obviously show CPL/CD signals. However, camphor, which is a rigid chiral luminophore, showed mirror-image CPL/CD signals. The dissymmetry ratio of CPL (glum) for the oligofluorenes increased discontinuously, ranging from ≈ −(0.2 to 2.0) × 10−3, when the viscosity of the liquids increased. When the fluorene ring number increased, the glum value extrapolated at [η] = 0 reached −0.8 × 10−3 at 420 nm, leading to (–)-CPL signals predicted in the vacuum state. Our comprehensive CPL and CD study should provide a possible answer to the molecular parity violation hypothesis arising due to the weak neutral current mediated by the Z0-boson.

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“…Until now, p-6P-as a member of the family of oligophenylene molecules-plays a role in current display technology based on organic electroluminescence [9]. The potential of the molecule in other optical applications is also demonstrated for optical waveguides [10][11][12], as a laser dye [13,14], in nonlinear optics [15] and in laser applications [16,17].…”

Section: The Application Relevance Of the Molecule Sexiphenylmentioning

confidence: 99%

In Situ Ellipsometric Monitoring of the Growth of Polycrystalline Silicon Thin Films by RF Plasma Chemical Vapor Deposition

Tachibana

Shirafuji

Hayashi

et al. 1994

Jpn. J. Appl. Phys.

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The crystallographic order in sexiphenyl thin films on dielectric surfaces (like thermally oxidized silicon, KCl(100), TiO 2 (110) mica (001)) and on metallic surfaces (like Au(111), Al (111)) are summarized. The combination of the surface science studies considering the first molecular layers on the substrate surfaces with crystallographic studies on sexiphenyl films reveals the influence of the first molecular layers on the thin-film structure. The interaction strength of the molecules with the substrate has a large influence on the preferred orientation of the crystallites relative to the substrate surface. In the case of metallic surfaces, the orientation of the molecules at the first monolayer determines the alignment of the crystallites in the thin film. In the case of dielectric surfaces, other types of preferred crystal orientations are observed, which is connected with the increasing importance of the intermolecular interaction strength in the first monolayers. Generally, it is observed that the bulk crystal structure is already present in thin films with a nominal thickness slightly larger than the monolayer thickness. The orientation and alignment of the initial crystal clusters at the surface determine the layer growth. The thin films show specific morphologies: depending on the orientation of the molecules relative to the substrate surface, either terraced islands or needle-like structures appear. The crystallite size parallel to the surface varies in a range from nanometres up to several tens of microns, depending on the type of substrate and the thin-film growth conditions. In the case of terraced islands, the crystallite size perpendicular to the surface is comparable with the nominal film thickness.

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Characterization of New Excimer Pumped UV Laser Dyes 3.P‐Quinqui‐, Sexi‐, Octi‐ and Deciphenyls

Cited by 15 publications

References 7 publications

A Really Convenient Synthesis of 2′,3″′-Dimethyl-p-sexiphenyl

A Really Convenient Synthesis of 2′,3″′-Dimethyl-p-sexiphenyl

Questions of Mirror Symmetry at the Photoexcited and Ground States of Non-Rigid Luminophores Raised by Circularly Polarized Luminescence and Circular Dichroism Spectroscopy: Part 1. Oligofluorenes, Oligophenylenes, Binaphthyls and Fused Aromatics

In Situ Ellipsometric Monitoring of the Growth of Polycrystalline Silicon Thin Films by RF Plasma Chemical Vapor Deposition

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