Top Organomet Chem (2020) 67: 191–226
https://doi.org/10.1007/3418_2020_49
# Springer Nature Switzerland AG 2020
Published online: 27 June 2020
Dealing with Spin States in Computational
Organometallic Catalysis
Marcel Swart
Contents
1 General Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
2 Spin States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
2.1 Where Do They Come From, Where Do They Go? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
3 Quantum Chemistry and Spin States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
3.1 Density Functional Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
3.2 Wavefunction Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
3.3 Combining Wavefunctions and Density Functionals: MC-PDFT and DMRG-PDFT 203
3.4 Methods Put to the Test: Recent Benchmark Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
4 Multi-state Reactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
4.1 Exchange-Enhanced Reactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
5 Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
5.1 C-H Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
5.2 Intradiol vs. Extradiol Selectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
5.3 Catalase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
6 Conclusions and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Abstract The present chapter gives an overview of the intriguing effects that spin
states have on catalysis and how this can (and cannot) be understood at present. For
instance, highly reactive transition-metal complexes are often too fast to be trapped
for characterization by spectroscopy and/or crystallography. While significant
advances have been made in theory with improved density functional approximations and more efficient wavefunction methods, these have not yet progressed to the
point of being robust general-purpose chemical tools. Recent developments in the
application of spectroscopy and theory on catalytically (in)active transition-metal
complexes are discussed together with future perspectives.
M. Swart (*)
IQCC and Department of Chemistry, Universitat de Girona, Girona, Spain
ICREA, Barcelona, Spain
e-mail: marcel.swart@gmail.com
https://doi.org/10.1007/3418_2020_49
# Springer Nature Switzerland AG 2020
Published online: 27 June 2020
Dealing with Spin States in Computational
Organometallic Catalysis
Marcel Swart
Contents
1 General Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
2 Spin States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
2.1 Where Do They Come From, Where Do They Go? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
3 Quantum Chemistry and Spin States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
3.1 Density Functional Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
3.2 Wavefunction Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
3.3 Combining Wavefunctions and Density Functionals: MC-PDFT and DMRG-PDFT 203
3.4 Methods Put to the Test: Recent Benchmark Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
4 Multi-state Reactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
4.1 Exchange-Enhanced Reactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
5 Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
5.1 C-H Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
5.2 Intradiol vs. Extradiol Selectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
5.3 Catalase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
6 Conclusions and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Abstract The present chapter gives an overview of the intriguing effects that spin
states have on catalysis and how this can (and cannot) be understood at present. For
instance, highly reactive transition-metal complexes are often too fast to be trapped
for characterization by spectroscopy and/or crystallography. While significant
advances have been made in theory with improved density functional approximations and more efficient wavefunction methods, these have not yet progressed to the
point of being robust general-purpose chemical tools. Recent developments in the
application of spectroscopy and theory on catalytically (in)active transition-metal
complexes are discussed together with future perspectives.
M. Swart (*)
IQCC and Department of Chemistry, Universitat de Girona, Girona, Spain
ICREA, Barcelona, Spain
e-mail: marcel.swart@gmail.com