Consecutive Photolyses of Naphthalenedicarboxylic Anhydrides in Low Temperature Matrixes:  Experimental and Computational Studies on Naphthynes and Benzocyclopentadienylideneketenes

Sato, Tadatake; Niino, Hiroyuki; Yabe, Akira

doi:10.1021/jp010746z

Cited by 24 publications

(23 citation statements)

References 34 publications

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“…1,2‐Naphthalynes21 generated in situ have often been used in organic synthesis 21a. However, they have low thermal stability and have only been detected in argon matrix at low temperature 21b,c…”

Section: Methodsmentioning

confidence: 99%

A Metallanaphthalyne Complex from Zinc Reduction of a Vinylcarbyne Complex

et al. 2007

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Transition metal containing metallaaromatics are a fascinating class of compounds because they can show properties of both organometallic compounds and aromatic organic compounds.[1] The most common metallaaromatics are metallabenzenes, stable examples of which have been found for osmium, [2] iridium, [3] platinum, [4] and ruthenium. [5] Other interesting metallaaromatics and related compounds isolated in recent years include metallanaphthalene, [6] metallapyrylium, [7] metallathiabenzene, [8] metallapyridine, [9] metallabenzyne, [10] isometallabenzene, [11] and metallabenzvalene.[12]Here we report the synthesis and characterization of the first metallanaphthalyne.Compared to metallabenzenes, the chemistry of metallabenzynes is less developed, partly due to the lack of convenient methods to construct the metallabenzyne ring. In a search for new routes to metallabenzynes, we tried to reduce the carbyne complex [OsCl 3 (CCH=CPh 2 )(PPh 3 ) 2 ] (1) with zinc.[13] We envisaged that Zn might first reduce the carbyne complex to the 16 e species [OsCl( CCH = CPh 2 )(PPh 3 ) 2 ], which could undergo C À H oxidative addition to give an osmanaphthalyne. Treatment of 1 with zinc powder in THF heated at reflux for 1.5 h produced the indenyl complex [{h 5 -C 9 H 6 (Ph)}OsCl(PPh 3 ) 2 ] (2), along with other unidentified species. Complex 2 can be isolated in 39 % yield from the reaction. The reaction is cleaner in the presence of PPh 3 . In this case, complex 2 can be isolated as a red solid in 71 % yield [Eq. (1)].

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Section: Methodsmentioning

confidence: 99%

A Metallanaphthalyne Complex from Zinc Reduction of a Vinylcarbyne Complex

et al. 2007

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“…17 A similar photolysis procedure was used to generate 1,2-and 2,3-naphthynes. 18,19 Some other less stable isomers, in particular both 2,6-and 1,5-naphthynes, were found as reaction intermediates and their diradical character was documented. [20][21][22] Unfortunately, as far as we know, there are no reliable experimental data concerning the electronic spectra of these species, in particular the magnitude of the S-T splittings, or the spin multiplicity of their ground states.…”

Section: Introductionmentioning

confidence: 96%

Energetics of naphthynes — Performance of reduced multi-reference coupled-cluster methods for diradicals

Paldus

2009

Can. J. Chem.

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The energetics of all the possible isomers of the didehydronaphthalene (naphthalyne or naphthyne) diradical has been examined using the reduced multi-reference (RMR) coupled-cluster (CC) method with singles and doubles (RMR CCSD) that employs a modest size MR CISD wave function as an external source of the most important (primary) triples and quadruples to account for nondynamic correlation effects in the presence of quasi-degeneracy, as well as by its perturbatively corrected version for the secondary triples, the RMR CCSD(T) method. The resulting energies are compared with those obtained by the standard single-reference (SR) CCSD and CCSD(T) approaches. In all cases, we used both the ccpVDZ basis set, as well as its restricted version cc-pVDZ* with deleted p-functions on hydrogens. Once the optimal geometry for each isomer was found, we computed the energy of the lowest-lying singlet and triplet states using the above mentioned CC methods, as well as the implied singlet-triplet splittings. These results enabled us to classify the isomers into three groups according to their stability and to determine, whenever possible, the spin multiplicity of the ground state. Finally, we point out the relationship between the extent of the diradical character of naphthyne isomers, the degree of their MR nature, the distance separating the radical centers, and, finally, the size of the largest doubly-excited cluster amplitude in their CC wave functions.Résumé : On a examiné les énergétiques de tous les isomères possibles du biradical du didéhydronaphtalène (naphtalyne ou naphtyne) en faisant appel à la méthode des agrégats couplés (AC) à multiréférence réduite (MRR) avec des simples et des doubles (MRR ACSD) qui utilise une fonction d'onde de taille modeste (MR CISD) comme source externe des triples et quadruples les plus importants (primaires) afin de tenir compte des effets de corrélation non dynamique en présence de quasi-dégénérescence; on a aussi fait appel à sa version corrigée d'un point de vue des perturbations pour les triples secondaires, la méthode MRR ACSD(T). On a comparé les énergies ainsi obtenues avec celles obtenues par les approches à ré-férence simple ACSD (RS) et ACSD(T). Dans tous les cas, on a utilisé l'ensemble de base cc-pVDZ ainsi que la version restreinte cc-pVDZ* desquelles les fonctions p de l'hydrogène ont été éliminées. Une fois que la géométrie optimale de chaque isomère a été trouvée, on a calculé les états singulet et triplet de plus basse énergie en utilisant les méthodes d'agrégats couplés mentionnées plus haut et on a aussi calculé la sèparation des niveaux de singulet et triplet qu'ils impliquent. Ces résultats permettent de classifier les isomères en trois groupes suivant leur stabilité et de déterminer, lorsque cela est possible, la multiplicité de spin de l'état fondamental. Enfin, on signale la relation entre le degré du caractère biradicalaire des isomères du naphtyne, le degré de leur nature de multiréférence, la distance qui sépare les centres radicalaires et enfin la taille de l'am...

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“…Die erste Matrixisolation von 2,3‐Didehydronaphthalin ( 10 ) wurde 1995 von Weltner et al beschrieben34 und in jüngster Zeit von Sato et al abschließend untersucht 35. 36 Durch Photolyse der Anhydride 11 und 12 sind 9 und 10 in guten Ausbeuten zugänglich, wenn die Photolysebedingungen sorgfältig gewählt werden 36. Besonders bemerkenswert sind erneut die Unterschiede der beiden Isomere im Vergleich zu 2 : Während 9 (analog zum Grundkörper, siehe Schema ) photochemisch zum Cyclopentadienylidenketen 13 carbonyliert wird (anders als 2 allerdings irreversibel), bleibt die Photocarbonylierung von 10 zu 14 völlig aus (Schema ) 36.…”

Section: Ortho‐didehydroaromatenunclassified