Conformational effects in the fluorescence and photochemistry of [2.n](9,10)anthracenophanes (n = 4, 5)

Dunand, A.; Ferguson, J.; Puza, M.; Robertson, G. B.

doi:10.1021/ja00530a036

Cited by 21 publications

(10 citation statements)

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“…tures.-We first analyse ab initio ST0-3G molecular orbitals of small molecules, p,p' -dibenzene (14) t and its biscyclobutanoderivative (15), § which model (1) and (5), respectively,~ in order to examine the low-lying virtual orbitals and high-lying occupied orbitals ( Figure). Compound (14) was the subject of The highest of the occupied SSA orbitals is essentially pure 1t, while the lowest empty SSA is pure cr*.…”

Section: Analysis Of St0-3g Molecular Orbitals Of Model Struc-mentioning

confidence: 99%

“…Both these changes in (15) increase the cr-7t* and 1t-cr* interactions, respectively. These are the reason for the longer calculated central bond distance of (15) compared to (14), and probably also the reason for the observed difference in the central bond distances between (I) and (5). However, at this point it is difficult to know the relative importance of these two interaction types.…”

Section: Analysis Of St0-3g Molecular Orbitals Of Model Struc-mentioning

confidence: 99%

“…We were intrigued by the extraordinarily long bond [1.77(1) A] t reported for biscyclobutano-derivative (5), 10 a photoisomer of [2.2](9, 1 0)-anthracenophane (12) (Table 1). Dunitz 12 has suggested the possibility offorming (5) by no-bond structures like (13). § Since the stated instability of (5) 10 might indicate some damage to the crystal by X-ray irradiation, we undertook neutron diffraction t Anthracene photodimer (1) is the oldest known photoadduct, I.…”

mentioning

confidence: 99%

“…Dunitz 12 has suggested the possibility offorming (5) by no-bond structures like (13). § Since the stated instability of (5) 10 might indicate some damage to the crystal by X-ray irradiation, we undertook neutron diffraction t Anthracene photodimer (1) is the oldest known photoadduct, I.…”

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confidence: 99%

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Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules

Dougherty¹,

Choi²,

Kaupp³

et al. 1986

J. Chem. Soc., Perkin Trans. 2

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Effects of substituents on the lengths of the central C-C single bond in the butterfly-shaped anthracene photodimers (1 )- (7) and lepidopterenes (8) are studied. X-Ray analysis of the photodimer (1 0) of 9,1 0-difluoroanthracene gave a C(9)-C(1 0') bond length of 1.631 (3) A. An attempt to re-determine molecular structure of the photoisomer (5) of [2.2] (9, 1 O)anthracenophane (12) by neutron diffraction analysis is also reported [C(9)-C(10'): obs. 1.64(1 ), calc. 1.63(1) A]. The D 2 structure that had been proposed for the minimum-energy conformation of (5) -7 Although many investigators have assumed that steric repulsions between the two ring systems are responsible for the unusual lengthening of the central bond in these molecules, recent work has demonstrated that steric factors are not as important but the through-bond interaction among four aromatic rings aligned almost perpendicular to the C-C bond is responsible. 1 · 8 · 9 Among a number of possibilities, 1t--+O'* and 0--+1t* interactions destabilize and elongate the mediating C-C bond. A quantitative perturbational MO study has indicated that the former type dominates over the latter. It seems interesting to investigate further the relationship between the strength of these orbital interactions, the length of mediating bond, and the chemical consequences like reactivity.

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Section: Analysis Of St0-3g Molecular Orbitals Of Model Struc-mentioning

confidence: 99%

Section: Analysis Of St0-3g Molecular Orbitals Of Model Struc-mentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules

Dougherty¹,

Choi²,

Kaupp³

et al. 1986

J. Chem. Soc., Perkin Trans. 2

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“…[4.4.4.4] compound 147, prepared in low yield by a Wittig reaction133 ; the cyclic hydrazide 148, which under oxidative conditions in aprotic media shows intramolecular sensitized chemiluminescence approaching the quantum yield of luminol134 135 ; [2.4]-and [2.5](9,10)anthracenophanes, the crystal structures of which have been determined136 ; and [3.3](l,4)naphthaleno(9,10)anthracenophane 149, which forms the photoisomer 150 on exposure to light 137. The related[3.3]paracyclo(9,10)anthracenophane undergoes a similar photochemical isomerization and also a thermally induced intramolecular Diels-Alder reaction.…”

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confidence: 99%

Condensed Benzenoid Cyclophanes

Reiss

1983

Organic Chemistry: A Series of Monographs

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Koordinationschemische Synthesemethoden zum Aufbau supramolekularer Verbindungen

2001

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Organisch‐präparativ arbeitenden Chemikern steht zur Herstellung von kleinen Molekülen, Nanostrukturen und Polymeren eine breite Palette zuverlässiger Reaktionen zur Verfügung. Koordinationschemiker hingegen sind damit konfrontiert, dass ihnen in der Übergangsmetallchemie im Vergleich zur Chemie des Kohlenstoffs selbst zur Synthese kleiner Molekülstrukturen nur relativ wenige mit hohen Ausbeuten verlaufende Reaktionen offenstehen, wenn man deren Zahl auf die Gesamtzahl der Übergangsmetalle umlegt. Dies liegt hauptsächlich an den im Vergleich zu den starken, kovalenten Bindungen in organischen Molekülen schwachen Metall‐Ligand‐Wechselwirkungen in Koordinationskomplexen. Eine schwache Bindung führt oft zu vielen Reaktionswegen, die sich energetisch nicht wesentlich unterscheiden, und folglich auch zu geringer Selektivität. Als Folge davon kamen viele Koordinationschemiker in den letzten Jahren zu der Erkenntnis, dass es leichter und ergiebiger sein könnte, einfache und zuverlässige Reaktionswege für supramolekulare Strukturen (im Nanomaßstab) so zu entwickeln, dass die wenigen Reaktionen aus der Koordinationschemie eingesetzt werden, die eine hohe Ausbeute liefern. Außerdem soll Kapital geschlagen werden aus den die Reaktionsrichtung dirigierenden Bindungen in den Metallzentren und aus den Strategien, die darauf abzielen, den Vorteil schwacher Metallbindungen in Koordinationskomplexen zu nutzen, um damit solche Architekturen aufzubauen. Die drei sich ergebenden Synthesestrategien, nämlich der „Symmetry‐Interaction“‐Ansatz, der „Directional‐Bonding“‐Ansatz und der „Weak‐Bonding“‐Ansatz nutzen alle Metallzentren als Strukturbausteine, um in gezielter Weise mit molekularen Komponenten supramolekulare Metallocyclophane aufzubauen. Diese drei Konzepte und ihre zugrunde liegenden Prinzipien werden in diesem Aufsatz behandelt, und es werden die sich daraus ergebenden Möglichkeiten verglichen und gegenübergestellt.

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Conformational effects in the fluorescence and photochemistry of [2.n](9,10)anthracenophanes (n = 4, 5)

Cited by 21 publications

References 3 publications

Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules

Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules

Condensed Benzenoid Cyclophanes

Koordinationschemische Synthesemethoden zum Aufbau supramolekularer Verbindungen

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Conformational effects in the fluorescence and photochemistry of [2.n](9,10)anthracenophanes (n = 4, 5)

Cited by 21 publications

References 3 publications

Effects of substituents on the length of central C(sp3)–C(sp3) bond in anthracene photodimers and related molecules

Effects of substituents on the length of central C(sp3)–C(sp3) bond in anthracene photodimers and related molecules

Condensed Benzenoid Cyclophanes

Koordinationschemische Synthesemethoden zum Aufbau supramolekularer Verbindungen

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Product

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Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules

Effects of substituents on the length of central C(sp³)–C(sp³) bond in anthracene photodimers and related molecules