TY - JOUR
AU - Wyatt Zagorec-Marks
AU - Leah Dodson
AU - Patrick Weis
AU - Erik Schneider
AU - Manfred Kappes
AU - J. Mathias Weber
AB - We investigated the structural and spectroscopic properties of singly deprotonated biliverdin anions in vacuo, using a combination of cryogenic ion spectroscopy, ion mobility spectrometry, and density functional theory. The ion mobility results show that at least two conformers are populated, with the dominant conformer at 75–90% relative abundance. The vibrational NH stretching signatures are sensitive to the tetrapyrrole structure, and they indicate that the tetrapyrrole system is in a helical conformation, consistent with simulated ion mobility collision cross sections. The vibrational spectrum in the fingerprint region of this singly deprotonated species shows that the two propionate groups share the remaining acidic proton. The S1 band of the electronic spectrum in vacuo is broad, despite ion trap temperatures of 20 K during ion preparation, with a congested Franck–Condon envelope showing partially resolved vibrational features. The vertical transition exhibits a small solvatochromic red shift (−320 cm–1) in aqueous solution.
BT - Journal of the American Chemical Society
DA - 2021-10
DO - 10.1021/jacs.1c08701
IS - 42
M3 - doi: 10.1021/jacs.1c08701
N1 - doi: 10.1021/jacs.1c08701
N2 - We investigated the structural and spectroscopic properties of singly deprotonated biliverdin anions in vacuo, using a combination of cryogenic ion spectroscopy, ion mobility spectrometry, and density functional theory. The ion mobility results show that at least two conformers are populated, with the dominant conformer at 75–90% relative abundance. The vibrational NH stretching signatures are sensitive to the tetrapyrrole structure, and they indicate that the tetrapyrrole system is in a helical conformation, consistent with simulated ion mobility collision cross sections. The vibrational spectrum in the fingerprint region of this singly deprotonated species shows that the two propionate groups share the remaining acidic proton. The S1 band of the electronic spectrum in vacuo is broad, despite ion trap temperatures of 20 K during ion preparation, with a congested Franck–Condon envelope showing partially resolved vibrational features. The vertical transition exhibits a small solvatochromic red shift (−320 cm–1) in aqueous solution.
PB - American Chemical Society
PY - 2021
SN - 0002-7863
SP - 17778
EP - 17785
T2 - Journal of the American Chemical Society
TI - Intrinsic Structure and Electronic Spectrum of Deprotonated Biliverdin: Cryogenic Ion Spectroscopy and Ion Mobility
UR - https://doi.org/10.1021/jacs.1c08701
VL - 143
ER -