TY - JOUR
T1 - Rational Design of an Acetylenic Infrared Probe with Enhanced Dipole Strength and Increased Vibrational Lifetime
AU - Kossowska, Dorota
AU - Park, Kwanghee
AU - Park, Jun Young
AU - Lim, Chaiho
AU - Kwak, Kyungwon
AU - Cho, Minhaeng
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/5/25
Y1 - 2019/5/25
N2 - Developing infrared (IR) probes is of great interest in biomolecular imaging and spectroscopy. We report our attempt to improve the IR properties of alkyne-derivatized compounds. The vibrational properties of the alkyne (CC) stretch mode of aromatic silylacetylene 1 and aliphatic silylacetylene 2 were studied using Fourier transform infrared and femtosecond IR pump-probe spectroscopies. We find that the insertion of silicon at the position adjacent to the alkyne group, separating it from the compound's main body, causes an approximately 10-fold increase in the dipole strength of the CC stretch mode and a lengthening of its vibrational lifetime from 5.6 ps for the acetylenic compound without a silicon atom acting like a thermal insulator to 50.6 and 50.4 ps for 1 and 2, respectively. The enhanced dipole strength and the increased lifetime of 1 allowed us to measure the 2D IR spectra for long waiting times up to 450 ps, which suggests that the dynamic observation range of 2D IR spectroscopy with these IR probes can be extended into the subnanosecond range where protein skeletal movements occur.
AB - Developing infrared (IR) probes is of great interest in biomolecular imaging and spectroscopy. We report our attempt to improve the IR properties of alkyne-derivatized compounds. The vibrational properties of the alkyne (CC) stretch mode of aromatic silylacetylene 1 and aliphatic silylacetylene 2 were studied using Fourier transform infrared and femtosecond IR pump-probe spectroscopies. We find that the insertion of silicon at the position adjacent to the alkyne group, separating it from the compound's main body, causes an approximately 10-fold increase in the dipole strength of the CC stretch mode and a lengthening of its vibrational lifetime from 5.6 ps for the acetylenic compound without a silicon atom acting like a thermal insulator to 50.6 and 50.4 ps for 1 and 2, respectively. The enhanced dipole strength and the increased lifetime of 1 allowed us to measure the 2D IR spectra for long waiting times up to 450 ps, which suggests that the dynamic observation range of 2D IR spectroscopy with these IR probes can be extended into the subnanosecond range where protein skeletal movements occur.
UR - http://www.scopus.com/inward/record.url?scp=85070875346&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcb.9b04925
DO - 10.1021/acs.jpcb.9b04925
M3 - Article
C2 - 31129961
AN - SCOPUS:85070875346
VL - 123
SP - 6274
EP - 6281
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 29
ER -