1,8‐Dipyrenylnaphthalenes: Syntheses, Molecular Structure, and Spectroscopic Properties

Wahl, Peter; Krieger, Claus; Schweitzer, Dieter; Staab, Heinz A.

doi:10.1002/cber.19841170120

Cited by 33 publications

(37 citation statements)

References 11 publications

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“…9 Bis(pyrenylcarboxy)alkanes 10 and polyether-linked bis(hemicyanines) 11 also adopt folded dimer geometries in nonpolar solvents due to the poor solvation of their polar functional groups. Excimer fluorescence has also been observed for 1,8-pyrenylnaphthalenes 12 and for a large number of cyclophanes which possess arene-dimer ground state geometries. 5,13, 14 The photophysical behavior of the latter excimers is strongly correlated with the cyclophane geometry.…”

Section: Introductionmentioning

confidence: 94%

Luminescence of extended and folded N,N′-diarylureas

Lewis

Kurth

Liu

2002

Photochem Photobiol Sci

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The relationship between molecular structure and luminescence of a series of secondary and tertiary N,N'-diarylureas (aryl = phenyl, 2-naphthyl, 2-anthryl, and pyren-1-yl) has been investigated at 77 K and at room temperature in the glass-forming solvent methyltetrahydrofuran. The secondary diarylureas possess planar extended structures, whereas the tertiary diarylureas possess folded structures in which the aryl groups are face-to-face. The secondary and tertiary diphenylureas display broad, weak fluorescence attributed to an n,pi* singlet state at low temperature and are non-fluorescent at room temperature. The other secondary diarylureas are strongly fluorescent both at 77 K and at room temperature. Their fluorescence resembles that of the parent arene and is assigned to a lowest pi,pi* singlet state. The fluorescence of the other tertiary diarylureas is similar to that of the secondary diarylureas at 77 K, but is broad and red-shifted in fluid solution, as a consequence of intramolecular excimer formation. The properties of these novel intramolecular excimers are compared with those of 1,3-diarylalkanes and paracyclophanes.

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Section: Introductionmentioning

confidence: 94%

Luminescence of extended and folded N,N′-diarylureas

Lewis

Kurth

Liu

2002

Photochem Photobiol Sci

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“…Examples include 1,2-di(1-pyrenyl)ethane (3), which cannot adopt a parallel sandwich structure, and [2.2](1,3)pyrenophane (6) (8) and [2.2](1,8)pyrenophane (7) (9), which have extended and splayed ground state structures, respectively. A particularly instructive example of the effect of overlap on pyrene fluorescence is provided by the 1,8-dipyrenyl-naphthalenes (8-10) investigated by Staab and co-workers (10). Both the di-2-pyrenylnaphthalene (10) and the syn rotamer of the di-1-pyrenylnaphthalene (8) have extensive overlap between pyrenes and display excimer fluorescence, whereas the antirotamer of the di-1-pyrenylnaphthalene (9) has minimal overlap and displays monomer fluorescence.…”

Section: Introductionmentioning

confidence: 99%

“…A particularly instructive example of the effect of overlap on pyrene fluorescence is provided by the 1,8-dipyrenyl-naphthalenes (8-10) investigated by Staab and co-workers (10). Both the di-2-pyrenylnaphthalene (10) and the syn rotamer of the di-1-pyrenylnaphthalene (8) have extensive overlap between pyrenes and display excimer fluorescence, whereas the antirotamer of the di-1-pyrenylnaphthalene (9) has minimal overlap and displays monomer fluorescence. Vögtle refers to systems in which two aryl groups are constrained to a faceto-face geometry by a single linker as "protophanes", to distinguish them from cyclophanes in which aryl groups are connected by two or more linkers (11).…”

Section: Introductionmentioning

confidence: 99%

Intramolecular excimer fluorescence from folded ground state rotamers of N,N'dimethyl-N,N'-dipyrenylurea protophanes

Lewis¹,

Kurth²

2003

Can. J. Chem.

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The molecular structure, absorption, and fluorescence spectra of N,N ′-dimethyl-N,N ′-di-1-pyrenylurea and N,N ′-dimethyl-N,N ′-di-2-pyrenylurea have been investigated and compared to the properties of N,N,N ′-trimethyl-N ′-pyrenylurea model compounds. Di-1-pyrenylurea exists as a mixture of folded (E,E) syn-and anti-rotamers that interconvert via flipping of one of the pyrene rings to an unfolded (E,Z) rotamer geometry. The symmetric di-2-pyrenylurea exists as a single folded (E,E) conformation which is in equilibrium with a less-stable, unfolded (E,Z) rotamer. The absorption and fluorescence spectra of the dipyrenylureas at 77 K in a rigid glass are similar to those of monopyrenylurea model compounds. However, in fluid solution, the dipyrenylureas exhibit excimer fluorescence and very weak monomer fluorescence which have identical decay times. This behavior is attributed to fast rotational equilibrium between folded rotamers which exhibit excimer fluorescence and unfolded rotamers which exhibit monomer fluorescence. The behavior of the dipyrenylureas is compared with that of other systems that form intramolecular pyrene excimers and diarylureas.Résumé : On a étudié la structure moléculaire et les spectres d'absorption et de fluorescence de la N,N ′-diméthyl-N,N ′-di-1-pyrénylurée et de la N,N ′-diméthyl-N,N ′,-di-2-pyrénylurée et on les a comparés aux propriétés correspondantes de composés modèles de la famille des N,N,N ′-triméthyl-N ′-pyrénylurée. La di-1-pyrénylurée existe sous la forme de mélange de rotamères syn-et anti-repliés (E,E) qui donnent lieu à une interconversion par le biais de l'inversion d'un des noyaux pyrène vers un rotamère de géométrie dépliée (E,Z). La di-2-pyrénylurée existe sous la forme d'une seule conformation repliée qui est en équilibre avec un rotamère déplié (E,Z) moins stable. Les spectres d'absorption et de fluorescence des dipyrénylurées à 77 K, dans un verre rigide, sont semblables à ceux des composés modèles de la famille des monopyrénylurées. Toutefois, en solution fluide, les dipyrénylurées présentent une fluorescence d'excimère et une très faible fluorescence de monomère qui ont des temps de dégénérescence identiques. On attribue ce comportement à un rapide équilibre rotationnel entre les rotamères repliés qui présentent de la fluorescence d'excimère et les rotamères dépliés qui présente de la fluorescence de monomère. On compare le comportement des dipyrénylurées avec celui des diarylurées et d'autres systèmes qui forment des excimères pyrènes intramoléculaires.

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“…To provide a parallel face‐to‐face spatial arrangement of two chromophores in close proximity, rigid aromatic scaffolds such as benzene,10 anthracene,11 biphenylene,12 [2.2]paracyclophane,9a, d, 13 ferrocene,14 and naphthalene3a, 9f, 15 have been used. Among these scaffolds, naphthalene has a notably short distance between its 1,8‐positions (2.6 Å),16 which is shorter than the typical π–π distance (3.4 Å) 17.…”

Section: Introductionmentioning

confidence: 99%

Fluorescence Enhancement of Covalently Linked 1‐Cyano‐1,2‐diphenylethene Chromophores with Naphthalene‐1,8‐diyl Linker Units: Analysis Based on Kinetic Constants

Hirose

Tsunoi

Fujimori

et al. 2014

Chemistry A European J

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The fluorescence enhancement effect of covalently fixed fluorescent chromophores has been investigated by means of kinetic analysis of decay rate constants and theoretical calculations. Derivatives of 1-cyano-1,2-diphenylethene dimer have a distorted cyclic structure when both ends are clipped with two naphthalene-1,8-diyl linker units. In contrast to the reference monomer derivative, which exhibits only slight fluorescence in solution (Φf < 0.01, τf < 0.1 ns), the dimer derivative shows high fluorescence quantum yield (Φf = 0.55) and long lifetime (τf = 20.6 ns) in dilute solution owing to suppression of the nonradiative decay process (knr = 0.022 ns(-1)). A V-shaped derivative with a covalent linker on one side showed moderate quantum yield and lifetime (Φf = 0.12, τf = 4.9 ns). According to the wavelength shifts of the absorption/fluorescence bands and theoretical calculations by time-dependent density functional theory (TD-DFT), we propose an H-aggregate-type excimer interaction.

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1,8‐Dipyrenylnaphthalenes: Syntheses, Molecular Structure, and Spectroscopic Properties

Cited by 33 publications

References 11 publications

Luminescence of extended and folded N,N′-diarylureas

Luminescence of extended and folded N,N′-diarylureas

Intramolecular excimer fluorescence from folded ground state rotamers of N,N'dimethyl-N,N'-dipyrenylurea protophanes

Fluorescence Enhancement of Covalently Linked 1‐Cyano‐1,2‐diphenylethene Chromophores with Naphthalene‐1,8‐diyl Linker Units: Analysis Based on Kinetic Constants

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