Editing Visible-Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N’- Bis(diphenylphosphino)-2,6-diaminopyridine Ligands

{{#doiinfobox: 10.1002/cssc.201901326}}
[[Category:Photocatalytic CO2 conversion to HCOOH]]

===Abstract===
====Summary====
A photochemical reduction of CO<sub>2</sub> to formic acid was shown using the ruthenium pincer complexes {{#moleculelink:|link=RQVVTEHURKEOIA-UHFFFAOYSA-M|image=false|width=300|height=200}} and {{#moleculelink:|link=XNTONGVEYKVCNE-UHFFFAOYSA-M|image=false|width=300|height=200}} as catalyst in combination with the ruthenium-based photosensitizer {{#moleculelink:|link=KLDYQWXVZLHTKT-UHFFFAOYSA-N|image=false|width=300|height=200}}. Turnover numbers (TONs) of 380 for formic acid were reached in dimethylformamide with complex {{#moleculelink:|link=XNTONGVEYKVCNE-UHFFFAOYSA-M|image=false|width=300|height=200}}. The experiments were conducted under visible-light irradiation (λ = 405 nm) using TEOA as sacrificial electron donor (see section SEDs below).
====Advances and special progress====
The authors report a novel molecular architecture for a ruthenium photocatalyst active in the reduction of CO<sub>2</sub> to formic acid, displaying competitive TONs and quantum yields up to 14%.

====Additional remarks====
===Content of the published article in detail===
The article contains results for the reduction of CO<sub>2</sub> to formic acid under visible-light catalysis using ruthenium complexes as catalysts. The catalytic system performs best (referring to the TON of formic acid production) with complex {{#moleculelink:|link=XNTONGVEYKVCNE-UHFFFAOYSA-M|image=false|width=300|height=200}} in dimethylformamide.
==== Catalyst====
<chemform smiles="C1C2N([*])P(C3C=CC=CC=3)(C3C=CC=CC=3)[Ru+]([C-]#[O+])([C-]#[O+])3P(C4C=CC=CC=4)(C4C=CC=CC=4)N([*])C(N=23)=CC=1.[Cl-]" inchikey="" inchi="" float="none" width="200" height="200" r1="H,Me">
  -INDIGO-01112413302D

  0  0  0  0  0  0  0  0  0  0  0 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 42 47 0 0 0
M  V30 BEGIN ATOM
M  V30 1 Cl 10.925 -1.975 0.0 0 CHG=-1
M  V30 2 C 7.95985 -2.27507 0.0 0
M  V30 3 C 9.69015 -2.27459 0.0 0
M  V30 4 C 8.82664 -1.77497 0.0 0
M  V30 5 C 9.69015 -3.27553 0.0 0
M  V30 6 C 7.95985 -3.28002 0.0 0
M  V30 7 N 8.82882 -3.77503 0.0 0
M  V30 8 N 7.09528 -3.78253 0.0 0
M  V30 9 N 10.5567 -3.7747 0.0 0
M  V30 10 P 7.09528 -4.78253 0.0 0
M  V30 11 P 10.5567 -4.7747 0.0 0
M  V30 12 R# 11.4227 -3.2747 0.0 0 RGROUPS=(1 1)
M  V30 13 R# 6.22925 -3.28253 0.0 0 RGROUPS=(1 1)
M  V30 14 Ru 8.825 -4.85 0.0 0 CHG=1
M  V30 15 C 11.5226 -4.51588 0.0 0
M  V30 16 C 6.12935 -4.52371 0.0 0
M  V30 17 C 12.745 -3.29121 0.0 0
M  V30 18 C 11.7813 -3.54917 0.0 0
M  V30 19 C 13.4532 -3.99851 0.0 0
M  V30 20 C 12.2337 -5.22601 0.0 0
M  V30 21 C 13.198 -4.96093 0.0 0
M  V30 22 C 4.45844 -4.97313 0.0 0
M  V30 23 C 5.42201 -5.23159 0.0 0
M  V30 24 C 4.19873 -4.00647 0.0 0
M  V30 25 C 5.8686 -3.55318 0.0 0
M  V30 26 C 4.90095 -3.30059 0.0 0
M  V30 27 C 6.59528 -5.64856 0.0 0
M  V30 28 C 6.59693 -7.37886 0.0 0
M  V30 29 C 7.09597 -6.51501 0.0 0
M  V30 30 C 5.59598 -7.37953 0.0 0
M  V30 31 C 5.59033 -5.64923 0.0 0
M  V30 32 C 5.0959 -6.51853 0.0 0
M  V30 33 C 11.0567 -5.64073 0.0 0
M  V30 34 C 12.556 -6.50445 0.0 0
M  V30 35 C 12.0574 -5.64034 0.0 0
M  V30 36 C 12.0561 -7.37163 0.0 0
M  V30 37 C 10.5548 -6.51137 0.0 0
M  V30 38 C 11.0604 -7.37421 0.0 0
M  V30 39 C 8.225 -5.96603 0.0 0 CHG=-1
M  V30 40 C 9.45 -5.96603 0.0 0 CHG=-1
M  V30 41 O 7.725 -6.83205 0.0 0 CHG=1
M  V30 42 O 9.95 -6.83205 0.0 0 CHG=1
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 2 4 2
M  V30 2 2 5 3
M  V30 3 1 2 6
M  V30 4 1 3 4
M  V30 5 2 6 7
M  V30 6 1 7 5
M  V30 7 1 6 8
M  V30 8 1 5 9
M  V30 9 1 8 10
M  V30 10 1 9 11
M  V30 11 1 9 12
M  V30 12 1 8 13
M  V30 13 10 10 14
M  V30 14 10 7 14
M  V30 15 10 11 14
M  V30 16 1 11 15
M  V30 17 1 10 16
M  V30 18 2 18 15
M  V30 19 2 19 17
M  V30 20 1 15 20
M  V30 21 1 17 18
M  V30 22 2 20 21
M  V30 23 1 21 19
M  V30 24 2 23 16
M  V30 25 2 24 22
M  V30 26 1 16 25
M  V30 27 1 22 23
M  V30 28 2 25 26
M  V30 29 1 26 24
M  V30 30 1 10 27
M  V30 31 2 29 27
M  V30 32 2 30 28
M  V30 33 1 27 31
M  V30 34 1 28 29
M  V30 35 2 31 32
M  V30 36 1 32 30
M  V30 37 1 11 33
M  V30 38 2 35 33
M  V30 39 2 36 34
M  V30 40 1 33 37
M  V30 41 1 34 35
M  V30 42 2 37 38
M  V30 43 1 38 36
M  V30 44 10 14 39
M  V30 45 10 14 40
M  V30 46 3 39 41
M  V30 47 3 40 42
M  V30 END BOND
M  V30 END CTAB
M  END
</chemform>

====Photosensitizer====
<chemform smiles="C1C=CN2[Ru+2]3(N4=CC=CC=C4C4=CC=CC=N43)(N3=CC=CC=C3C=2C=1)1N2C(C3N1=CC=CC=3)=CC=CC=2.[P-](F)(F)(F)(F)(F)F.[P-](F)(F)(F)(F)(F)F" inchi="1S/3C10H8N2.2F6P.Ru/c3*1-3-7-11-9(5-1)10-6-2-4-8-12-10;2*1-7(2,3,4,5)6;/h3*1-8H;;;/q;;;2*-1;+2" inchikey="KLDYQWXVZLHTKT-UHFFFAOYSA-N" height="200px" width="300px" float="none">
  -INDIGO-11272316292D

  0  0  0  0  0  0  0  0  0  0  0 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 51 57 0 0 0
M  V30 BEGIN ATOM
M  V30 1 C 8.40037 -1.10079 0.0 0
M  V30 2 C 9.26594 -2.59904 0.0 0
M  V30 3 C 9.26687 -1.6014 0.0 0
M  V30 4 N 8.3991 -3.09951 0.0 0
M  V30 5 C 7.53006 -1.60327 0.0 0
M  V30 6 C 7.53586 -2.60333 0.0 0
M  V30 7 C 10.132 -3.09904 0.0 0
M  V30 8 C 11.8623 -3.09739 0.0 0
M  V30 9 C 10.9984 -2.59835 0.0 0
M  V30 10 C 11.8629 -4.09833 0.0 0
M  V30 11 N 10.1326 -4.10398 0.0 0
M  V30 12 C 11.0019 -4.59841 0.0 0
M  V30 13 N 10.1848 -6.15007 0.0 0
M  V30 14 C 11.9152 -6.14959 0.0 0
M  V30 15 C 11.0516 -5.64997 0.0 0
M  V30 16 C 11.9152 -7.15053 0.0 0
M  V30 17 C 10.1848 -7.15502 0.0 0
M  V30 18 C 11.0538 -7.65003 0.0 0
M  V30 19 C 9.31882 -7.65502 0.0 0
M  V30 20 C 8.4551 -9.15433 0.0 0
M  V30 21 C 9.31921 -8.65573 0.0 0
M  V30 22 C 7.58792 -8.65444 0.0 0
M  V30 23 N 8.44818 -7.15313 0.0 0
M  V30 24 C 7.58534 -7.65875 0.0 0
M  V30 25 C 4.83485 -6.20007 0.0 0
M  V30 26 N 6.56515 -6.19959 0.0 0
M  V30 27 C 5.70164 -5.69997 0.0 0
M  V30 28 C 6.56515 -7.20053 0.0 0
M  V30 29 C 4.83485 -7.20502 0.0 0
M  V30 30 C 5.70382 -7.70003 0.0 0
M  V30 31 C 5.70164 -4.69997 0.0 0
M  V30 32 C 4.83506 -3.20231 0.0 0
M  V30 33 C 4.8348 -4.19994 0.0 0
M  V30 34 C 5.70157 -2.70125 0.0 0
M  V30 35 N 6.57161 -4.19691 0.0 0
M  V30 36 C 6.56515 -3.19686 0.0 0
M  V30 37 Ru 8.44661 -5.11294 0.0 0 CHG=2
M  V30 38 P 14.442 -2.725 0.0 0 CHG=-1
M  V30 39 F 15.308 -2.225 0.0 0
M  V30 40 F 13.576 -2.225 0.0 0
M  V30 41 F 14.442 -3.725 0.0 0
M  V30 42 F 15.308 -3.225 0.0 0
M  V30 43 F 14.442 -1.725 0.0 0
M  V30 44 F 13.576 -3.225 0.0 0
M  V30 45 P 14.5 -5.675 0.0 0 CHG=-1
M  V30 46 F 15.366 -5.175 0.0 0
M  V30 47 F 13.634 -5.175 0.0 0
M  V30 48 F 14.5 -6.675 0.0 0
M  V30 49 F 15.366 -6.175 0.0 0
M  V30 50 F 14.5 -4.675 0.0 0
M  V30 51 F 13.634 -6.175 0.0 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 2 3 1
M  V30 2 2 4 2
M  V30 3 1 1 5
M  V30 4 1 2 3
M  V30 5 2 5 6
M  V30 6 1 6 4
M  V30 7 1 2 7
M  V30 8 2 9 7
M  V30 9 2 10 8
M  V30 10 1 7 11
M  V30 11 1 8 9
M  V30 12 2 11 12
M  V30 13 1 12 10
M  V30 14 2 15 13
M  V30 15 2 16 14
M  V30 16 1 13 17
M  V30 17 1 14 15
M  V30 18 2 17 18
M  V30 19 1 18 16
M  V30 20 1 17 19
M  V30 21 2 21 19
M  V30 22 2 22 20
M  V30 23 1 19 23
M  V30 24 1 20 21
M  V30 25 2 23 24
M  V30 26 1 24 22
M  V30 27 2 27 25
M  V30 28 2 28 26
M  V30 29 1 25 29
M  V30 30 1 26 27
M  V30 31 2 29 30
M  V30 32 1 30 28
M  V30 33 1 27 31
M  V30 34 2 33 31
M  V30 35 2 34 32
M  V30 36 1 31 35
M  V30 37 1 32 33
M  V30 38 2 35 36
M  V30 39 1 36 34
M  V30 40 10 35 37
M  V30 41 10 37 26
M  V30 42 10 37 4
M  V30 43 10 11 37
M  V30 44 10 37 13
M  V30 45 10 23 37
M  V30 46 1 38 39
M  V30 47 1 38 40
M  V30 48 1 38 41
M  V30 49 1 38 42
M  V30 50 1 38 43
M  V30 51 1 38 44
M  V30 52 1 45 46
M  V30 53 1 45 47
M  V30 54 1 45 48
M  V30 55 1 45 49
M  V30 56 1 45 50
M  V30 57 1 45 51
M  V30 END BOND
M  V30 END CTAB
M  END
</chemform>

====Investigation====
{{#experimentlist:|form=Photocatalytic_CO2_conversion_experiments|name=Table 1}}
==== Sacrificial electron donor ====
In this study, the experiments were done with the sacrificial electron donors TEOA ([[Molecule:100507|100507]]).
====Additives====
In this study, no additives were tested.