Using Ultrafast X‑ray Spectroscopy To Address
Questions in Ligand-Field Theory: The Excited State Spin and Structure
of [Fe(dcpp)2]2+
Posted on 2019-06-26 - 14:47
We
have employed a range of ultrafast X-ray spectroscopies in an
effort to characterize the lowest energy excited state of [Fe(dcpp)2]2+ (where dcpp is 2,6-(dicarboxypyridyl)pyridine).
This compound exhibits an unusually short excited-state lifetime for
a low-spin Fe(II) polypyridyl complex of 270 ps in a room-temperature
fluid solution, raising questions as to whether the ligand-field strength
of dcpp had pushed this system beyond the 5T2/3T1 crossing point and stabilizing the latter
as the lowest energy excited state. Kα and Kβ X-ray emission
spectroscopies have been used to unambiguously determine the quintet
spin multiplicity of the long-lived excited state, thereby establishing
the 5T2 state as the lowest energy excited state
of this compound. Geometric changes associated with the photoinduced
ligand-field state conversion have also been monitored with extended
X-ray absorption fine structure. The data show the typical average
Fe-ligand bond length elongation of ∼0.18 Å for a 5T2 state and suggest a high anisotropy of the primary
coordination sphere around the metal center in the excited 5T2 state, in stark contrast to the nearly perfect octahedral
symmetry that characterizes the low-spin 1A1 ground state structure. This study illustrates how the application
of time-resolved X-ray techniques can provide insights into the electronic
structures of moleculesin particular, transition metal complexesthat
are difficult if not impossible to obtain by other means.
CITE THIS COLLECTION
DataCite
3 Biotech
3D Printing in Medicine
3D Research
3D-Printed Materials and Systems
4OR
AAPG Bulletin
AAPS Open
AAPS PharmSciTech
Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg
ABI Technik (German)
Academic Medicine
Academic Pediatrics
Academic Psychiatry
Academic Questions
Academy of Management Discoveries
Academy of Management Journal
Academy of Management Learning and Education
Academy of Management Perspectives
Academy of Management Proceedings
Academy of Management Review
Britz, Alexander; Gawelda, Wojciech; Assefa, Tadesse A.; Jamula, Lindsey L.; Yarranton, Jonathan T.; Galler, Andreas; et al. (2019). Using Ultrafast X‑ray Spectroscopy To Address
Questions in Ligand-Field Theory: The Excited State Spin and Structure
of [Fe(dcpp)2]2+. ACS Publications. Collection. https://doi.org/10.1021/acs.inorgchem.9b01063
or
Select your citation style and then place your mouse over the citation text to select it.
SHARE
Usage metrics
Read the peer-reviewed publication
AUTHORS (28)
AB
Alexander Britz
WG
Wojciech Gawelda
TA
Tadesse A. Assefa
LJ
Lindsey L. Jamula
JY
Jonathan T. Yarranton
AG
Andreas Galler
DK
Dmitry Khakhulin
MD
Michael Diez
MH
Manuel Harder
GD
Gilles Doumy
AM
Anne Marie March
EB
Éva Bajnóczi
ZN
Zoltán Németh
MP
Mátyás Pápai
ER
Emese Rozsályi
DS
Dorottya Sárosiné Szemes
HC
Hana Cho
SM
Sriparna Mukherjee
CL
Chang Liu
TK
Tae Kyu Kim
KEYWORDS
270 psroom-temperature fluid solutionultrafast X-ray spectroscopiesLigand-Field Theoryexcited-state lifetimek αphotoinduced ligand-field state conversioncoordination sphereExcited State SpinFe-ligand bond length elongationlow-spin 1ligand-field strengthtime-resolved X-ray techniquesoctahedral symmetryAddress QuestionsK β X-ray emission spectroscopiesGeometric changes5 T 2 state1 ground state structureX-ray absorptiondata showmetal centercompound exhibits