Bimetallic platinum complexes have interesting luminescent properties and feature long-lasting vibrational coherence and ultrafast intersystem crossing (ISC) after photoexcitation. Ultrafast triplet formation is driven by very strong spin-orbit coupling in these platinum (II) systems, where relativistic theoretical approaches beyond first-order perturbation theory are desirable. Using a fully variational relativistic theoretical method recently developed by the authors, we investigate the origins of ultrafast ISC in the [Pt(ppy) (μ-tBu2pz)]2 complex (ppy = phenylpyridine, pz = pyrazolate). Spin-orbit coupling values, evaluated along a Born-Oppenheimer molecular dynamics trajectory, are used to propagate electronic populations in time. Using this technique, we estimate ultrafast ISC rates of 15–134 fs in this species for the possible ISC pathways into the three low-lying triplet states.
REFERENCES
1.
J. G.
Williams
, S.
Develay
, D. L.
Rochester
, and L.
Murphy
, “Optimising the luminescence of platinum(II) complexes and their application in organic light emitting devices (OLEDs)
,” Coord. Chem. Rev.
252
, 2596
–2611
(2008
).2.
C.-L.
Ho
, W.-Y.
Wong
, B.
Yao
, Z.
Xie
, L.
Wang
, and Z.
Lin
, “Synthesis, characterization, photophysics and electrophosphorescent applications of phosphorescent platinum cyclometalated complexes with 9-arylcarbazole moieties
,” J. Organomet. Chem.
694
, 2735
–2749
(2009
).3.
R. M.
van der Veen
, C. J.
Milne
, A.
El Nahhas
, F. A.
Lima
, V.-T.
Pham
, J.
Best
, J. A.
Weinstein
, C. N.
Borca
, R.
Abela
, C.
Bressler
, and M.
Chergui
, “Structural determination of a photochemically active diplatinum molecule by time-resolved EXAFS spectroscopy
,” Angew. Chem., Int. Ed.
48
, 2711
–2714
(2009
).4.
R. M.
van der Veen
, A.
Cannizzo
, F.
van Mourik
, A.
Vlček
, and M.
Chergui
, “Vibrational relaxation and intersystem crossing of binuclear metal complexes in solution
,” J. Am. Chem. Soc.
133
, 305
–315
(2011
).5.
D. M.
Roundhill
, H. B.
Gray
, and C. M.
Che
, “Pyrophosphito-bridged diplatinum chemistry
,” Acc. Chem. Res.
22
, 55
–61
(1989
).6.
I. V.
Novozhilova
, A. V.
Volkov
, and P.
Coppens
, “Theoretical analysis of the triplet excited state of the [Pt2(H2P2O5)4]4− ion and comparison with time-resolved x-ray and spectroscopic results
,” J. Am. Chem. Soc.
125
, 1079
–1087
(2003
).7.
G.
Levi
, M.
Pápai
, N. E.
Henriksen
, A. O.
Dohn
, and K. B.
Møller
, “Solution structure and ultrafast vibrational relaxation of the PtPOP complex revealed by ΔSCF-QM/MM direct dynamics simulations
,” J. Phys. Chem. C
122
, 7100
–7119
(2018
).8.
B.
Ma
, J.
Li
, P. I.
Djurovich
, M.
Yousufuddin
, R.
Bau
, and M. E.
Thompson
, “Synthetic control of Pt-Pt separation and photophysics of binuclear platinum complexes
,” J. Am. Chem. Soc.
127
, 28
–29
(2004
).9.
B.
Ma
, P. I.
Djurovich
, S.
Garon
, B.
Alleyne
, and M. E.
Thompson
, “Platinum binuclear complexes as phosphorescent dopants for monochromatic and white organic light-emitting diodes
,” Adv. Funct. Mater.
16
, 2438
–2446
(2006
).10.
A.
Chakraborty
, J. E.
Yarnell
, R. D.
Sommer
, S.
Roy
, and F. N.
Castellano
, “Excited-state processes of cyclometalated platinum(II) charge-transfer dimers bridged by hydroxypyridines
,” Inorg. Chem.
57
, 1298
–1310
(2018
).11.
J. V.
Lockard
, A. A.
Rachford
, G.
Smolentsev
, A. B.
Stickrath
, X.
Wang
, X.
Zhang
, K.
Atenkoffer
, G.
Jennings
, A.
Soldatov
, A. L.
Rheingold
, F. N.
Castellano
, and L. X.
Chen
, “Triplet excited state distortions in a pyrazolate bridged platinum dimer measured by x-ray transient absorption spectroscopy
,” J. Phys. Chem. A
114
, 12780
–12787
(2010
).12.
S.
Cho
, M. W.
Mara
, X.
Wang
, J. V.
Lockard
, A. A.
Rachford
, F. N.
Castellano
, and L. X.
Chen
, “Coherence in metal–metal-to-ligand-charge-transfer excited states of a dimetallic complex investigated by ultrafast transient absorption anisotropy
,” J. Phys. Chem. A
115
, 3990
–3996
(2011
).13.
S. E.
Brown-Xu
, M. S. J.
Kelley
, K. A.
Fransted
, A.
Chakraborty
, G. C.
Schatz
, F. N.
Castellano
, and L. X.
Chen
, “Tunable excited-state properties and dynamics as a function of Pt–Pt distance in pyrazolate-bridged Pt(II) dimers
,” J. Phys. Chem. A
120
, 543
–550
(2016
).14.
P.
Kim
, M. S.
Kelley
, A.
Chakraborty
, N. L.
Wong
, R. P.
Van Duyne
, G. C.
Schatz
, F. N.
Castellano
, and L. X.
Chen
, “Coherent vibrational wavepacket dynamics in platinum(II) dimers and their implications
,” J. Phys. Chem. C
122
, 14195
–14204
(2018
).15.
D. B.
Lingerfelt
, P. J.
Lestrange
, J. J.
Radler
, S. E.
Brown-Xu
, P.
Kim
, F. N.
Castellano
, L. X.
Chen
, and X.
Li
, “Can excited state electronic coherence Be tuned via molecular structural modification? A first-principles quantum electronic dynamics study of pyrazolate-bridged Pt(II) dimers
,” J. Phys. Chem. A
121
, 1932
–1939
(2017
).16.
J. J.
Radler
, D. B.
Lingerfelt
, F. N.
Castellano
, L. X.
Chen
, and X.
Li
, “Role of vibrational dynamics on excited-state electronic coherence in a binuclear platinum complex
,” J. Phys. Chem. A
122
, 5071
–5077
(2018
).17.
C. M.
Marian
, “Spin-orbit coupling and intersystem crossing in molecules
,” Wiley Interdiscip. Rev.: Comput. Mol. Sci.
2
, 187
–203
(2012
).18.
T. J.
Penfold
, E.
Gindensperger
, C.
Daniel
, and C. M.
Marian
, “Spin-vibronic mechanism for intersystem crossing
,” Chem. Rev.
118
, 6975
–7025
(2018
).19.
A. J. S.
Valentine
and X.
Li
, “Toward the evaluation of intersystem crossing rates with variational relativistic methods
,” J. Chem. Phys.
151
, 084107
(2019
).20.
K. G.
Dyall
and K.
Fægri
, Jr., Introduction to Relativistic Quantum Chemistry
(Oxford University Press
, 2007
).21.
22.
W.
Kutzelnigg
and W.
Liu
, “Quasirelativistic theory equivalent to fully relativistic theory
,” J. Chem. Phys.
123
, 241102
(2005
).23.
W.
Liu
and D.
Peng
, “Infinite-order quasirelativistic density functional method based on the exact matrix quasirelativistic theory
,” J. Chem. Phys.
125
, 044102
(2006
).24.
D.
Peng
, W.
Liu
, Y.
Xiao
, and L.
Cheng
, “Making four- and two-component relativistic density functional methods fully equivalent based on the idea of ‘from atoms to molecule
,’” J. Chem. Phys.
127
, 104106
(2007
).25.
M.
Ilias
and T.
Saue
, “An infinite-order relativistic Hamiltonian by a simple one-step transformation
,” J. Chem. Phys.
126
, 064102
(2007
).26.
W.
Liu
and D.
Peng
, “Exact two-component Hamiltonians revisited
,” J. Chem. Phys.
131
, 031104
(2009
).27.
W.
Liu
, “Ideas of relativistic quantum chemistry
,” Mol. Phys.
108
, 1679
–1706
(2010
).28.
T.
Saue
, “Relativistic Hamiltonians for chemistry: A primer
,” ChemPhysChem
12
, 3077
–3094
(2011
).29.
Z.
Li
, Y.
Xiao
, and W.
Liu
, “On the spin separation of algebraic two-component relativistic Hamiltonians
,” J. Chem. Phys.
137
, 154114
(2012
).30.
D.
Peng
, N.
Middendorf
, F.
Weigend
, and M.
Reiher
, “An efficient implementation of two-component relativistic exact-decoupling methods for large molecules
,” J. Chem. Phys.
138
, 184105
(2013
).31.
F.
Egidi
, J. J.
Goings
, M. J.
Frisch
, and X.
Li
, “Direct atomic-orbital-based relativistic two-component linear response method for calculating excited-state fine structures
,” J. Chem. Theory Comput.
12
, 3711
–3718
(2016
).32.
J. J.
Goings
, J. M.
Kasper
, F.
Egidi
, S.
Sun
, and X.
Li
, “Real time propagation of the exact two component time-dependent density functional theory
,” J. Chem. Phys.
145
, 104107
(2016
).33.
L.
Konecny
, M.
Kadek
, S.
Komorovsky
, O. L.
Malkina
, K.
Ruud
, and M.
Repisky
, “Acceleration of relativistic electron dynamics by means of X2C transformation: Application to the calculation of nonlinear optical properties
,” J. Chem. Theory Comput.
12
, 5823
–5833
(2016
).34.
F.
Egidi
, S.
Sun
, J. J.
Goings
, G.
Scalmani
, M. J.
Frisch
, and X.
Li
, “Two-component non-collinear time-dependent spin density functional theory for excited state calculations
,” J. Chem. Theory Comput.
13
, 2591
–2603
(2017
).35.
J. M.
Kasper
, P. J.
Lestrange
, T. F.
Stetina
, and X.
Li
, “Modeling L2,3-edge x-ray absorption spectroscopy with real-time exact two-component relativistic time-dependent density functional theory
,” J. Chem. Theory Comput.
14
, 1998
–2006
(2018
).36.
A.
Petrone
, D. B.
Williams-Young
, S.
Sun
, T. F.
Stetina
, and X.
Li
, “An efficient implementation of two-component relativistic density functional theory with torque-free auxiliary variables
,” Eur. Phys. J. B
91
, 169
(2018
).37.
J. C.
Boettger
, “Approximate two-electron spin-orbit coupling term for density-functional-theory DFT calculations using the Douglas-Kroll-Hess transformation
,” Phys. Rev. B
62
, 7809
–7815
(2000
).38.
M. J.
Frisch
, G. W.
Trucks
, H. B.
Schlegel
, G. E.
Scuseria
, M. A.
Robb
, J. R.
Cheeseman
, G.
Scalmani
, V.
Barone
, G. A.
Petersson
, H.
Nakatsuji
, X.
Li
, M.
Caricato
, A. V.
Marenich
, J.
Bloino
, B. G.
Janesko
, R.
Gomperts
, B.
Mennucci
, H. P.
Hratchian
, J. V.
Ortiz
, A. F.
Izmaylov
, J. L.
Sonnenberg
, D.
Williams-Young
, F.
Ding
, F.
Lipparini
, F.
Egidi
, J.
Goings
, B.
Peng
, A.
Petrone
, T.
Henderson
, D.
Ranasinghe
, V. G.
Zakrzewski
, J.
Gao
, N.
Rega
, G.
Zheng
, W.
Liang
, M.
Hada
, M.
Ehara
, K.
Toyota
, R.
Fukuda
, J.
Hasegawa
, M.
Ishida
, T.
Nakajima
, Y.
Honda
, O.
Kitao
, H.
Nakai
, T.
Vreven
, K.
Throssell
, J. A.
Montgomery
, Jr., J. E.
Peralta
, F.
Ogliaro
, M. J.
Bearpark
, J. J.
Heyd
, E. N.
Brothers
, K. N.
Kudin
, V. N.
Staroverov
, T. A.
Keith
, R.
Kobayashi
, J.
Normand
, K.
Raghavachari
, A. P.
Rendell
, J. C.
Burant
, S. S.
Iyengar
, J.
Tomasi
, M.
Cossi
, J. M.
Millam
, M.
Klene
, C.
Adamo
, R.
Cammi
, J. W.
Ochterski
, R. L.
Martin
, K.
Morokuma
, O.
Farkas
, J. B.
Foresman
, and D. J.
Fox
, gaussian 16, Revision B.01, Gaussian, Inc.
, Wallingford, CT
, 2016
.39.
X.
Li
and M. J.
Frisch
, “Energy-represented direct inversion in the iterative subspace within a hybrid geometry optimization method
,” J. Chem. Theory Comput.
2
, 835
–839
(2006
).40.
T.
Yanai
, D. P.
Tew
, and N. C.
Handy
, “A new hybrid exchange–correlation functional using the coulomb-attenuating method (CAM-B3LYP)
,” Chem. Phys. Lett.
393
, 51
–57
(2004
).41.
P. J.
Hay
and W. R.
Wadt
, “Ab initio effective core potentials for molecular calculations. Potentials for potassium to gold including the outermost core orbitals
,” J. Chem. Phys.
82
, 299
–310
(1985
).42.
A. J.
Atkins
and L.
González
, “Trajectory surface-hopping dynamics including intersystem crossing in [Ru(bpy)3]2+
,” J. Phys. Chem. Lett.
8
, 3840
–3845
(2017
).43.
T.
Noro
, M.
Sekiya
, and T.
Koga
, “Segmented contracted basis sets for atoms H through Xe: Sapporo-(DK)-nZP sets (n = D, T, Q)
,” Theor. Chem. Acc.
131
, 1124
(2012
).44.
R. L.
Martin
, “Natural transition orbitals
,” J. Chem. Phys.
118
, 4775
–4777
(2003
).45.
A. V.
Luzanov
and O. A.
Zhikol
, “Electron invariants and excited state structural analysis for electronic transitions within CIS, RPA, and TDDFT models
,” Int. J. Quantum Chem.
110
, 902
–924
(2010
).46.
F.
Plasser
and H.
Lischka
, “Analysis of excitonic and charge transfer interactions from quantum chemical calculations
,” J. Chem. Theory Comput.
8
, 2777
–2789
(2012
).47.
F.
Plasser
, M.
Wormit
, and A.
Dreuw
, “New tools for the systematic analysis and visualization of electronic excitations. I. Formalism
,” J. Chem. Phys.
141
, 024106
(2014
).48.
M. A.
El-Sayed
, “Spin-orbit coupling and the radiationless processes in nitrogen heterocyclics
,” J. Chem. Phys.
38
, 2834
–2838
(1963
).49.
X.
Li
, J. M.
Millam
, and H. B.
Schlegel
, “Ab initio molecular dynamics studies of the photodissociation of formaldehyde, H2CO → H2 + CO: Direct classical trajectory calculations by MP2 and density functional theory
,” J. Chem. Phys.
113
, 10062
–10067
(2000
).50.
X.
Li
, J. M.
Millam
, and H. B.
Schlegel
, “Glyoxal photodissociation. An ab initio direct classical trajectory study of C2H2O2 → H2 + 2CO
,” J. Chem. Phys.
114
, 8897
–8904
(2001
).51.
G.
Granucci
, M.
Persico
, and A.
Toniolo
, “Direct semiclassical simulation of photochemical processes with semiempirical wave functions
,” J. Chem. Phys.
114
, 10608
–10615
(2001
).52.
F.
Plasser
, G.
Granucci
, J.
Pittner
, M.
Barbatti
, M.
Persico
, and H.
Lischka
, “Surface hopping dynamics using a locally diabatic formalism: Charge transfer in the ethylene dimer cation and excited state dynamics in the 2-pyridone dimer
,” J. Chem. Phys.
137
, 22A514
(2012
).© 2019 Author(s).
2019
Author(s)
You do not currently have access to this content.
