Conformational structures of 3-cyanoindole-(H2O) (n= 0–2): Franck–Condon simulations

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

“…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. 38,39 Using TD-DFT with the LC-BLYP, M06-2X, and B3LYP functionals, the same energetic order of the lowest pp* states was found compared to calculations using the second-order approximate coupled cluster singles and doubles model (CC2). 34 In 3-cyanoindole, the order of the 1 L a and 1 L b states is reversed again, the 1 L b state being the lower one as determined by rotationally resolved electronic Stark spectroscopy.…”

“…40 The water clusters of 3-cyanoindole(H 2 O) n with n = 1, 2 have been studied in the group of Choi by UV-UV hole burning and IR-dip spectroscopy. 38,39 Based on the comparison of the IR-dip spectra with the results of normal mode analyses and a Franck-Condon analysis of the mass-selected R2P spectra of 3-cyanoindole(H 2 O) n with n = 1, 2 they deduced a linearly bound water moiety with an N-HÁ Á ÁOH 2 binding motif. This structure was confirmed by the rotational constants from rotationally resolved electronic spectroscopy.…”

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

“…It could be shown that the lowest excited singlet state has 1 L b character, while the excitation in the n = 1 and n = 2 water clusters is to the 1 L a state. 3 Ahn et al 26 investigated 3-cyanoindole and several 3-cyanoindolewater clusters, using mass-selected resonant two-photon ionization (R2PI) and UV-UV hole-burning (UVHB) spectroscopy. Assignments of the different cluster structures were made on the basis of a Franck-Condon analysis of the vibronic spectra.…”

Spectroscopic and theoretical studies of jet‐cooled 3‐cyanoindole ammonia clusters in the gas phase

“…5,7,[11][12][13][14][15] These gas phase spectroscopic results extensively studied by experimentally and theoretically played an important role in determining the excited-state properties of the indole molecular systems. 13,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Cyanoindole having a cyano group, an electronwithdrawing group, has provided much interest in electronic emission studies. 24,[31][32][33][34] Depending on the position of the cyano group in the pyrrole ring or the benzene ring of the indole, the spectroscopic properties of the excited state and molecular functions are affected significantly due to the changes in the electron density of cyanoindoles.…”

“…Substituted indole-solvent clusters with water, ammonia, and alcohol in the gas phase have been studied by resonant two-photon ionization (R2PI) spectroscopy. 13,20,25,27 Moreover, some cyanoindoles and their water clusters have been investigated by rotationally resolved electronic spectroscopy and theoretical calculations by Schmitt et al [22][23][24]30 In our previous report, we investigated the conformationally resolved structures of 3CI monomer and its water clusters in the excited state by using mass-selected one-color resonant two-photon ionization (1C-R2PI) and ultraviolet-ultraviolet hole-burning (UV-UV HB) spectroscopy in molecular beams. As a result, there was only a single conformer observed in the 3CI monomer study, and the mass-selected R2PI spectrum of 3CI-water clusters showed a 1:1 water cluster and a 1:2 water cluster through the 3CI 1:1 water cluster cation mass channel due to the photofragmentation by the loss of one water molecule after the photoionization.…”