TY - JOUR
T1 - Excited-State Switching in Rhenium(I) Bipyridyl Complexes with Donor-Donor and Donor-Acceptor Substituents
AU - Sutton, Joshua J.
AU - Preston, Dan
AU - Traber, Philipp
AU - Steinmetzer, Johannes
AU - Wu, Xue
AU - Kayal, Surajit
AU - Sun, Xue Z.
AU - Crowley, James D.
AU - George, Michael W.
AU - Kupfer, Stephan
AU - Gordon, Keith C.
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/6/23
Y1 - 2021/6/23
N2 - The optical properties of two Re(CO)3(bpy)Cl complexes in which the bpy is substituted with two donor (triphenylamine, TPA, ReTPA2) as well as both donor (TPA) and acceptor (benzothiadiazole, BTD, ReTPA-BTD) groups are presented. For ReTPA2 the absorption spectra show intense intraligand charge-transfer (ILCT) bands at 460 nm with small solvatochromic behavior; for ReTPA-BTD the ILCT transitions are weaker. These transitions are assigned as TPA → bpy transitions as supported by resonance Raman data and TDDFT calculations. The excited-state spectroscopy shows the presence of two emissive states for both complexes. The intensity of these emission signals is modulated by solvent. Time-resolved infrared spectroscopy definitively assigns the excited states present in CH2Cl2 to be MLCT in nature, and in MeCN the excited states are ILCT in nature. DFT calculations indicated this switching with solvent is governed by access to states controlled by spin-orbit coupling, which is sufficiently different in the two solvents, allowing to select out each of the charge-transfer states.
AB - The optical properties of two Re(CO)3(bpy)Cl complexes in which the bpy is substituted with two donor (triphenylamine, TPA, ReTPA2) as well as both donor (TPA) and acceptor (benzothiadiazole, BTD, ReTPA-BTD) groups are presented. For ReTPA2 the absorption spectra show intense intraligand charge-transfer (ILCT) bands at 460 nm with small solvatochromic behavior; for ReTPA-BTD the ILCT transitions are weaker. These transitions are assigned as TPA → bpy transitions as supported by resonance Raman data and TDDFT calculations. The excited-state spectroscopy shows the presence of two emissive states for both complexes. The intensity of these emission signals is modulated by solvent. Time-resolved infrared spectroscopy definitively assigns the excited states present in CH2Cl2 to be MLCT in nature, and in MeCN the excited states are ILCT in nature. DFT calculations indicated this switching with solvent is governed by access to states controlled by spin-orbit coupling, which is sufficiently different in the two solvents, allowing to select out each of the charge-transfer states.
UR - http://www.scopus.com/inward/record.url?scp=85108691014&partnerID=8YFLogxK
U2 - 10.1021/jacs.1c02755
DO - 10.1021/jacs.1c02755
M3 - Article
C2 - 34111929
AN - SCOPUS:85108691014
SN - 0002-7863
VL - 143
SP - 9082
EP - 9093
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 24
ER -