High resolution spectroscopy of several rovibronically excited bands of 5-cyanoindole – The effect of vibrational averaging

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The rotationally resolved electronic spectra of the origin bands of 3-cyanoindole, 3-cyanoindole(d1), and the 3-cyanoindole-(H2O)1 cluster have been measured and analyzed using evolutionary algorithms. For the monomer, permanent dipole moments of 5.90 D for the ground state, and of 5.35 D for the lowest excited singlet state have been obtained from electronic Stark spectroscopy. The orientation of the transition dipole moment is that of an 1Lb state for the monomer. The water moiety in the water cluster could be determined to be trans-linearly bound to the NH group of 3-cyanoindole, with an NHO hydrogen bond length of 201.9 pm in the electronic ground state. Like the 3-cyanoindole monomer, the 3-cyanoindole-water cluster also shows an 1Lb-like excited singlet state. The excited state lifetime of isolate 3-cyanoindole in the gas phase has been determined to be 9.8 ns, and that of 3-cyanoindole(d1) has been found to be 14.8 ns, while that of the 1 : 1 water cluster is considerably shorter (3.6 ns). The excited state lifetime of 3-cyanoindole(d1) in D2O solution has been found to be smaller than 20 ps.

Section: Introductionmentioning

confidence: 73%

Rotationally resolved electronic spectroscopy of 3-cyanoindole and the 3-cyanoindole–water complex

Schneider

Hebestreit

Lindic

et al. 2018

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“…Rotationally resolved electronic spectra of 5-cyanoindole have been presented. [34][35][36] From the comparison of the experimental findings to quantum chemical calculations at the coupled cluster level of theory, the lowest excited singlet state could be shown to be the 1 L a in contrast to most other indole derivatives, which have the 1 L b state as lowest excited state. 5-Cyanoindole(H 2 O) n with n = 0-2 has been investigated using UV-UV hole burning and IR-dip spectroscopy by Min et al 37 They found a different photodissociation pattern of the 5-cyanoindole-water clusters compared to the respective 3-cyanoindole-water clusters.…”

Section: Introductionmentioning

confidence: 99%

Structures, dipole moments and excited state lifetime of isolated 4-cyanoindole in its ground and lowest electronically excited singlet states

Hebestreit

Schneider

Lartian

et al. 2019

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“…Based on the direction of the transition dipole moments it was previously concluded that these bands strongly couple to the higher-lying L b state via Herzberg-Teller coupling. 9 The Duschinsky matrix is nearly diagonal for these modes, excluding strong mode mixing to be responsible for the observed deviations. While our Herzberg-Teller analysis shows that the intensity of the 350 cm À1 band can be explained by the additional contributions from the HT terms in eqn (4), the deviations of the bands at 875 and 884 cm À1 cannot be explained on the basis of Herzberg-Teller contributions to the FC spectrum.…”

Section: Discussionmentioning

confidence: 91%

“…8 Oeltermann et al deduced the structure of 5-cyanoindole in the ground and the lowest electronically excited singlet states using rotationally resolved electronic spectroscopy. 6 Higher vibronic bands of 5CI have been studied by Brand et al 9 While previous studies concentrated on the geometric structures in the different electronic states and the nature of the excited states, we seek to understand the coupling to other electronically excited states in the present contribution.…”

Section: Introductionmentioning

confidence: 99%

Determination of the geometry change of 5-cyanoindole upon electronic excitation from a combined Franck–Condon/rotational constants fit

Stuhlmann

Gräßle

Schmitt

2014

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The geometry change of 5-cyanoindole upon electronic excitation from the ground to the lowest excited singlet state has been determined from a combined fit of the rotational constant changes upon excitation and the vibronic intensities in various fluorescence emission spectra using the Franck-Condon principle. The so determined geometry change is compared to the results of ab initio calculations and points to an excited state geometry, which is La-like in the nomenclature of Platt. A mode selective coupling of vibronic bands to higher-lying excited states is discussed on the basis of Herzberg-Teller contributions to the Frank-Condon intensities.