respect, allowing for well-defined reductive or oxidative chemistry, depending on
the type of backbone and redox-active fragments incorporated. The reversible
storage of electrons or ‘holes’ (i.e. oxidizing equivalents) into an organic (pincer)
backbone allows not only for transformations that would otherwise be very difficult
or impossible but modulating the ligand oxidation state and, in effect the ligand field
strength associated with it, also impacts, e.g. the Lewis acidity of or the induced spin
state at the metal centre. These strategies have already been utilized for both selected
stoichiometric and catalytic applications. It is deemed only a matter of time before
new ligand designs will appear that may not only prove useful to investigate
questions related to electronic structure of metal complexes but also be useful for
other (catalytic) transformations, perhaps even excluding the need for transition
metals altogether.
References
1. Li H, Gonçalves TP, Lupp D, Huang K-W (2019) ACS Catal 9:1619–1629
2. Verhoeven DGA, Moret M-E (2016) Dalton Trans 45:15762–15778
3. Khusnutdinova JR, Milstein D (2015) Angew Chem Int Ed 54:12236–12273
4. van der Vlugt JI (2012) Eur J Inorg Chem:363–375
5. van der Vlugt JI, Reek JNH (2009) Angew Chem Int Ed 48:8832–8846
6. Khan FF, Chowdhury AD, Lahiri GK (2020) Eur J Inorg Chem:11381–11146
7. van der Vlugt JI (2019) Chem A Eur J 25:2651–2662
8. Luca OR, Crabtree RH (2013) Chem Soc Rev 42:1440–1459
9. Praneeth VKK, Ringenberg MR, Ward Angew TR (2012) Chem Int Ed 51:10228–10234
10. Lyaskovskyy V, de Bruin B (2012) ACS Catal 2:270–279
11. Kaim W (2012) Eur J Inorg Chem:343–348
12. Chaudhuri P, Nazari Verani C, Bill E, Bothe E, Weyhermüller T, Wieghardt K (2001) J Am
Chem Soc 123:2213–2223
13. Jørgensen CK (1966) Coord Chem Rev 1:164–178
14. Kaim W, Schwederski B (2010) Coord Chem Rev 254:1580–1588
15. Nikolaevskaya EN, Druzhkov NO, Syroeshkin MA, Egorov MP (2020) Coord Chem Rev
417:213353.1–213353.18
16. Caulton KG (2012) Eur J Inorg Chem:435–443
17. Alyea EC, Ferguson G, Restivo RJ (1975) Inorg Chem 14:2491–2495
18. Small BL, Brookhart M, Bennett AMA (1998) J Am Chem Soc 120:4049–4050
19. Britovsek GJP, Gibson VC, Kimberley BS, Maddox PJ, McTavish SJ, Solan GA, White AJP,
Williams DJ (1998) Chem Commun:849–850
20. Gibson VC, Redshaw C, Solan GA (2007) Chem Rev 107:1745–1776
21. Small BL (2015) Acc Chem Res 48:2599–2611
22. de Bruin B, Bill E, Bothe E, Weyhermüller T, Wieghardt K (2000) Inorg Chem 39:2936–2947
23. Budzelaar PHM, de Bruin B, Gal AW, Wieghardt K, van Lenthe JH (2001) Inorg Chem
40:4649–4655
24. Braun JD, Gray PA, Sidhu BK, Nemez DB, Herbert DE (2020) Dalton Trans. https://doi.org/
10.1039/d0dt00543f
25. Darmon JM, Turner ZR, Lobkovsky E, Chirik PJ (2012) Organometallics 31:2275–2285
26. Sandoval JJ, Melero C, Palma P, Álvarez E, Rodríguez-Delgado A, CÁmpora J (2016)
Organometallics 35:3336–3343
Redox-Active Pincer Ligands
173
the type of backbone and redox-active fragments incorporated. The reversible
storage of electrons or ‘holes’ (i.e. oxidizing equivalents) into an organic (pincer)
backbone allows not only for transformations that would otherwise be very difficult
or impossible but modulating the ligand oxidation state and, in effect the ligand field
strength associated with it, also impacts, e.g. the Lewis acidity of or the induced spin
state at the metal centre. These strategies have already been utilized for both selected
stoichiometric and catalytic applications. It is deemed only a matter of time before
new ligand designs will appear that may not only prove useful to investigate
questions related to electronic structure of metal complexes but also be useful for
other (catalytic) transformations, perhaps even excluding the need for transition
metals altogether.
References
1. Li H, Gonçalves TP, Lupp D, Huang K-W (2019) ACS Catal 9:1619–1629
2. Verhoeven DGA, Moret M-E (2016) Dalton Trans 45:15762–15778
3. Khusnutdinova JR, Milstein D (2015) Angew Chem Int Ed 54:12236–12273
4. van der Vlugt JI (2012) Eur J Inorg Chem:363–375
5. van der Vlugt JI, Reek JNH (2009) Angew Chem Int Ed 48:8832–8846
6. Khan FF, Chowdhury AD, Lahiri GK (2020) Eur J Inorg Chem:11381–11146
7. van der Vlugt JI (2019) Chem A Eur J 25:2651–2662
8. Luca OR, Crabtree RH (2013) Chem Soc Rev 42:1440–1459
9. Praneeth VKK, Ringenberg MR, Ward Angew TR (2012) Chem Int Ed 51:10228–10234
10. Lyaskovskyy V, de Bruin B (2012) ACS Catal 2:270–279
11. Kaim W (2012) Eur J Inorg Chem:343–348
12. Chaudhuri P, Nazari Verani C, Bill E, Bothe E, Weyhermüller T, Wieghardt K (2001) J Am
Chem Soc 123:2213–2223
13. Jørgensen CK (1966) Coord Chem Rev 1:164–178
14. Kaim W, Schwederski B (2010) Coord Chem Rev 254:1580–1588
15. Nikolaevskaya EN, Druzhkov NO, Syroeshkin MA, Egorov MP (2020) Coord Chem Rev
417:213353.1–213353.18
16. Caulton KG (2012) Eur J Inorg Chem:435–443
17. Alyea EC, Ferguson G, Restivo RJ (1975) Inorg Chem 14:2491–2495
18. Small BL, Brookhart M, Bennett AMA (1998) J Am Chem Soc 120:4049–4050
19. Britovsek GJP, Gibson VC, Kimberley BS, Maddox PJ, McTavish SJ, Solan GA, White AJP,
Williams DJ (1998) Chem Commun:849–850
20. Gibson VC, Redshaw C, Solan GA (2007) Chem Rev 107:1745–1776
21. Small BL (2015) Acc Chem Res 48:2599–2611
22. de Bruin B, Bill E, Bothe E, Weyhermüller T, Wieghardt K (2000) Inorg Chem 39:2936–2947
23. Budzelaar PHM, de Bruin B, Gal AW, Wieghardt K, van Lenthe JH (2001) Inorg Chem
40:4649–4655
24. Braun JD, Gray PA, Sidhu BK, Nemez DB, Herbert DE (2020) Dalton Trans. https://doi.org/
10.1039/d0dt00543f
25. Darmon JM, Turner ZR, Lobkovsky E, Chirik PJ (2012) Organometallics 31:2275–2285
26. Sandoval JJ, Melero C, Palma P, Álvarez E, Rodríguez-Delgado A, CÁmpora J (2016)
Organometallics 35:3336–3343
Redox-Active Pincer Ligands
173