Interchromophoric interactions in ionic 1,n-dicarbazolylalkanes

Masnovi, John; Krafcik, Randolph B.; Baker, Ronald J.; Towns, R. L. R.

doi:10.1021/j100368a053

Cited by 14 publications

(16 citation statements)

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“…The only notable discrepancy between the carbazole rings of (I) and (II) and that of carbazole is found in the C4a--C4b distance, which is 1.43 A for (I) and (II) ( Table 3) but 1.48 A for carbazole. This distance is 1.43A in the structure of dicarbazolylmethane (Masnovi et al, 1990) and 1.40 .& in the disordered carbazoletetracyanoethylene (1/2) complex (Masnovi et al, 1991). The conformations of (I) and (II) are shown in Fig.…”

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confidence: 94%

“…We found that spatial relationships in such model systems affect the electronic interactions between the carbazole groups (Masnovi, Krafcik, Baker & Towns, 1990). Therefore, we have undertaken singlecrystal X-ray structure determinations of (I) and of a higher analog, 1,5-di(9-carbazolyl)pentane (II), in order to establish the preferred relative orientation of the carbazole groups in these compounds.…”

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confidence: 99%

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Structures of 1,3-di(9-carbazolyl)propane and 1,5-di(9-carbazolyl)pentane. Polyvinylcarbazole model compounds

Baker¹,

Chen²,

Krafcik³

et al. 1991

Acta Crystallogr C

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confidence: 94%

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confidence: 99%

Structures of 1,3-di(9-carbazolyl)propane and 1,5-di(9-carbazolyl)pentane. Polyvinylcarbazole model compounds

Baker¹,

Chen²,

Krafcik³

et al. 1991

Acta Crystallogr C

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“…For the dicarbazolylalkanes, a minor process involving double hydrogen migration to the leaving iminium group was significant only for the n = 3 derivative and was taken as evidence for interaction between the two carbazole ring systems in the gas phase which was also strongest for this compound in solution 28…”

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confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…We have previously reported evidence for the association of anthracenes and their radical cations, which affects their properties and reactivity in solution 26–28. Due to differences in the stability of the radical ions, however, anthracenes behave differently than carbazoles 28, 29. In particular, anthracenes exhibit a greater tendency to mutually associate, as in excimers,30–32 which would be expected to resemble radical cation dimers in many respects.…”

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confidence: 99%

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Gaseous cation chemistry and chain‐length effects in electron ionization and collision‐induced dissociation mass spectraof symmetric 1,n‐bis(9‐anthracenyl)alkanes

Schildcrout

Masnovi

2011

J. Mass Spectrom.

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The behavior of the gaseous cations resulting from EI (30 and 70 eV) of the bichromophoric title compounds 1-5 (for n = 1-5, respectively) is examined by ion-trap mass spectrometry, including collision-induced dissociation (CID) with variation in collision energy. These results are compared with those from anthracene and 9-methylanthracene and with previously reported mass spectrometric results for 3 and dicarbazolylalkanes. Rather than using the kinetic method to obtain ion energetics where the fragmentation mechanism is clear, as commonly done, the method is used here with relative complementary-ion abundances from CID to test the proposed fragmentation mechanisms using B3LYP calculations of relative ionization energies and optimized geometries of ionic and neutral fragments. Hydrogen migrations are common, and skeletal rearrangements including formation of expanded, fused and spiro rings are proposed in several cases. Of the chain cleavages, α-homolysis giving C(15) H(11) (+) , likely as dibenzotropylium, is most important for each of 1-5 except 3, where β-cleavage to C(16) H(13) (+) dominates with a proposed methyldibenzotropylium structure. α-Cleavage was important also in the dicarbazolylalkanes. A previous inference of a McLafferty rearrangement to explain C(15) H(12) (+•) from 3 is not supported by the present results. The fragmentation behavior of 1-5 depends strongly on n and implies significant interchromophoric interaction between anthracenyl groups.

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