The electronic spectrum of pyrrole in the vapour and crystal

Bavia, M.; Bertinelli, F.; Taliani, C.; Zauli, C.

doi:10.1080/00268977600100361

Cited by 74 publications

(68 citation statements)

References 13 publications

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“…7,14 -16 The lowest-energy band has an intensity maximum near 6.0 eV while the second energy has it near 7.5 eV. That most of the intensity of the latter can be attributed to the presence of high-lying valence excited states has been supported both experimentally 11,[15][16][17][18] and theoretically. 7,[9][10][11][12] In the same energy range a number of Rydberg transitions have also been identified.…”

Section: Introductionmentioning

confidence: 50%

“…The experimental absorption spectrum of pyrrole has two intense bands 11,[13][14][15][16][17][18][19] ͑see previous papers for earlier references͒. 7,14 -16 The lowest-energy band has an intensity maximum near 6.0 eV while the second energy has it near 7.5 eV.…”

Section: Introductionmentioning

confidence: 99%

“…The dipole-forbidden character of the lowest electronic transition in pyrrole was firmly established in our previous work 7 and the assignment was supported by most of the previous 7,[20][21][22] and most recent theoretical studies, [9][10][11][12] in agreement with earlier analyses. 15,16 However, for the lowest-energy band recorded in the energy range 5.5-6.5 eV one can find in the theoretical literature ͑not in the experimental one͒ as many arguments in favor of the Rydberg character of the band as about its valence nature ͑for historical details the reader is referred to previous references͒. 7,[10][11][12]15 In the traditional interpretation of the pyrrole spectrum, 15 the intensity of the lowestenergy band is associated with the presence in this region of the 1 B 2 valence excited state of * character.…”

Section: Introductionmentioning

confidence: 99%

“…There is agreement between theory and experiment regarding the nature and placement of the lowest singlet excited state of pyrrole. The character of the peak detected at 5.22 eV 13,[15][16][17] has been clearly determined to be of Rydberg nature, corresponding to a transition to the 1 1 A 2 (3s) Rydberg state. The dipole-forbidden character of the lowest electronic transition in pyrrole was firmly established in our previous work 7 and the assignment was supported by most of the previous 7,[20][21][22] and most recent theoretical studies, [9][10][11][12] in agreement with earlier analyses.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical characterization of the lowest-energy absorption band of pyrrole

Roos

Malmqvist

Molina

et al. 2002

The Journal of Chemical Physics

122

145

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The lowest-energy band of the electronic spectrum of pyrrole has been studied with vibrational resolution by using multiconfigurational second-order perturbation theory ͑CASPT2͒ and its multistate extension ͑MS-CASPT2͒ in conjunction with large atomic natural orbital-type basis sets including Rydberg functions. The obtained results provide a consistent picture of the recorded spectrum in the energy region 5.5-6.5 eV and confirm that the bulk of the intensity of the band arises from a * intravalence transition, in contradiction to recent theoretical claims. Computed band origins for the 3s,3p Rydberg electronic transitions are in agreement with the available experimental data, although new assignments are suggested. As illustrated in the paper, the proper treatment of the valence-Rydberg mixing is particularly challenging for ab initio methodologies and can be seen as the main source of deviation among the recent theoretical results as regards the position of the low-lying valence excited states of pyrrole.

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Section: Introductionmentioning

confidence: 50%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theoretical characterization of the lowest-energy absorption band of pyrrole

Roos

Malmqvist

Molina

et al. 2002

The Journal of Chemical Physics

122

145

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“…4,5 The second absorption band had been attributed to the presence of highlying excited valence states. 3,4,12,18 The simultaneous occurrence of many overlapping Rydberg series and valence excited states is responsible for the complex structure of the electronic spectrum of pyrrole. 19 These overlapping and valenceÀRydberg mixing interactions make the theoretical calculations of excited states challenging.…”

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confidence: 99%

Femtosecond Multiphoton Ionization of Pyrrole

Liu

Wang

2011

J. Phys. Chem. A

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Pyrrole is one of the simplest six-π-electron five-membered heteroatomic aromatic molecules, which plays an important role in organometallic materials, pesticides, organic polymers, and biologically active compounds. 1 For these reasons, pyrrole and its derivatives have attracted great attention in past decades, both experimentally and theoretically. 2À17 After excitation, pyrrole shows a rich photochemistry, which is still not well understood in full detail.It is well-known that there are two dominant bands in the ultraviolet absorption spectrum of pyrrole below the first ionization threshold. 2,17 These two absorption bands have been assigned to excitations of two bright ππ* states of symmetry, 1B 2 and 1A 1 , centered at 6.0 and 7.5 eV, respectively. 5,17 Despite extensive theoretical research, the interpretation is still not verified. A number of low-lying Rydberg transitions are expected to be interleaved in the first absorption band region. 4,5 The second absorption band had been attributed to the presence of highlying excited valence states. 3,4,12,18 The simultaneous occurrence of many overlapping Rydberg series and valence excited states is responsible for the complex structure of the electronic spectrum of pyrrole. 19 These overlapping and valenceÀRydberg mixing interactions make the theoretical calculations of excited states challenging. 5,17À19 There is another relative weak and sharp absorption band, centered at about 6.8 eV, which has been assigned to Rydberg transition to 4B 1 (1a 2 3d) state (6.78 eV). 5 Two nearby bands, at 6.798 and 7.02 eV, were assigned to the excitation of the 2A 2 (1a 2 4s) and 5A 1 (2b 1 3p) Rydberg states. 4,5 In the most recent calculation, transitions ascribed to several excited states, such as 2B 2 , 4B 1 , and 3A 2 , were reported to be 6.58, 6.65, and 6.7 eV, respectively, which is close to this absorption band. 17 In the REMPI spectrum, a transition at 6.798 eV was ten times more intense than 6.781 eV (3d origin), which was ascribed to the excitation of a valence state 1A 1 (ππ*). 4,5 However, these optically allowed transitions were not observed in the nanosecond (1 + 1) REMPI spectra from 390 to 310 nm in a cold molecular beam experiment, which was supposed to be due to ultrafast deactivation via conical intersections with the dissociative 1A 2 (πσ*) and 1B 1 (πσ*) states. 20 The REMPI spectral features indicated that 2 + 1 resonance ionization in this region proceeded via Rydberg orbitals. 4,20 More recent work has focused on the role of NÀH bond dissociation in the deactivation of low excited states of pyrrole. 19,21À25 The observation of prompt NÀH photodissociation 22,23 was ascribed to dynamics occurring in the 1 πσ* states (with symmetry A 2 and B 1 ), which lie below the principal absorptions to 1 ππ* states. An ab initio study 21 suggested that S 1 r S 0 transitions should be absent from the REMPI spectrum due to either dissociation of 1 ππ* states via conical intersections with 1 πσ* states or internal conversion to the ground state. Recent time-depe...

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Physical and Theoretical Aspects of 1H‐Pyrroles

Chadwick

1990

Chemistry of Heterocyclic Compounds: A Series of Monographs

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The electronic spectrum of pyrrole in the vapour and crystal

Cited by 74 publications

References 13 publications

Theoretical characterization of the lowest-energy absorption band of pyrrole

Theoretical characterization of the lowest-energy absorption band of pyrrole

Femtosecond Multiphoton Ionization of Pyrrole

Physical and Theoretical Aspects of 1H‐Pyrroles

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