Angshuk Saha, Eduard Masferrer-Rius, Max T.G.M Derks, Abhinav Bairagi, Bowei Yuan, Martin Lutz, Daniel L.J. Broere, Jana Roithová, Robertus J.M. Klein Gebbink. “Bio-inspired manganese-catalyzed aromatic C–H hydroxylation leads to an intramolecular C(sp²)–C(sp²) coupling reaction: A product inhibition study in aromatic hydroxylation.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007624/v1

Complex 1a control in HFIP without aromatic substrate
UV–vis (1a 0.026 mM, room temperature), stepwise acetic acid addition 10, 30, 50 and 100 equiv. acetic acid: the solution remained colorless without changes in the spectra
UV–vis after H₂O₂ addition (reported in main paper) Broad shoulders around 420 nm; the solution became brown
UV–vis after H₂O₂ addition (reported in SI) 5 equiv. H₂O₂: peak around 420 nm; the solution changed from colorless to brown. No further color change after another portion of H₂O₂, 10 equiv. total
Main, p. 6; SI, pp. 8–9
Complex 1a during catalytic oxidation of propylbenzene with acetic acid in HFIP
In-situ UV–vis (0 °C; 1a 5 µmol; propylbenzene 0.5 mmol; acetic acid 1 mmol; H₂O₂ 0.5 mmol added over 60 min) Bands at 406, 450, 530 and 681 nm developed over time; minor absorption increase after 1 min; the 406 and 681 nm peaks began to develop after 13 min and the 530 nm peak after 21 min; after onset, the peaks developed at a similar rate. Changes were sharper and more defined than for 1b, especially at 400–500 nm, and the 530 and 681 nm peaks were slightly more intense than for 1b. The deep greenish-purple color developed faster than for 1b
Main, pp. 6–7; SI, pp. 10–11, 16
Complex 1b during catalytic oxidation of propylbenzene with acetic acid in HFIP
In-situ UV–vis (0 °C; 1b 5 µmol; propylbenzene 0.5 mmol; acetic acid 1 mmol; H₂O₂ 0.5 mmol added over 60 min) Bands at 406, 530 and 681 nm developed over time; the 450 nm band was not observed; no initial absorption change was observed; the 406, 530 and 681 nm peaks developed simultaneously after 23 min, eventually leading to the typical deep greenish-purple color
Main, pp. 6–7; SI, pp. 13–14, 16
Complex 1a during catalytic oxidation of propylbenzene with dichloroacetic acid in HFIP
In-situ UV–vis (0 °C; 1a 5 µmol; propylbenzene 0.5 mmol; dichloroacetic acid 1 mmol; H₂O₂ 0.5 mmol added over 60 min) Bands at 406, 450, 530 and 681 nm developed simultaneously after 27 min, leading to a deep greenish-purple solution
Main, p. 7; SI, pp. 11–12
Complex 1b during catalytic oxidation of propylbenzene with dichloroacetic acid in HFIP
In-situ UV–vis (0 °C; 1b 5 µmol; propylbenzene 0.5 mmol; dichloroacetic acid 1 mmol; H₂O₂ 0.5 mmol added over 60 min) No spectral bands were observed
Main, p. 7; SI, pp. 14–15
Complex 1a and acetic acid in HFIP
HRMS conditions Total flow 20 µL min⁻¹; 1a 0.375 mM; acetic acid 1.25 mM
HRMS, [Mn(II)(bpmcn)(OTf)]⁺ Observed m/z 528.1185; theoretical 528.1209; TfO = CF₃SO₃
HRMS, [Mn(II)(bpmcn)(OAc)]⁺ Observed m/z 438.1799; theoretical 438.1822; AcO = CH₃COO
Main, p. 9; SI, p. 19
Complex 1a, acetic acid and H₂O₂ in HFIP
HRMS conditions Total flow 25 µL min⁻¹; 1a 0.3 mM; acetic acid 1.00 mM; H₂O₂ 2.2 mM
HRMS, [Mn(II)(bpmcn)(OAc)]⁺ Observed m/z 438.1796; theoretical 438.1822; AcO = CH₃COO
HRMS, [Mn(II)(bpmcn)(OTf)]⁺ Observed m/z 528.1185; theoretical 528.1209; TfO = CF₃SO₃
HRMS, [Mn(III)(bpmcn)(HFIP-H)₂]⁺ Observed m/z 713.1532; theoretical 713.1552; HFIP-H = 1,1,1,3,3,3-hexafluoropropan-2-olate
Main, p. 10; SI, p. 19
Complex 1a, acetic acid, H₂O₂ and propylbenzene in HFIP after 1 min
HRMS conditions Total flow 25 µL min⁻¹; 1a 0.3 mM; acetic acid 1.00 mM; H₂O₂ 2.2 mM; propylbenzene 0.5 mM
HRMS, [Mn(II)(bpmcn)(OAc)]⁺ Observed m/z 438.1795; theoretical 438.1822
HRMS, [Mn(II)(bpmcn)(OTf)]⁺ Observed m/z 528.1185 in the full trace and 528.1186 in the higher-m/z trace; theoretical 528.1209
HRMS, [Mn(III)(bpmcn)(HFIP-H)₂]⁺ Observed m/z 713.1532; theoretical 713.1552; HFIP-H = 1,1,1,3,3,3-hexafluoropropan-2-olate
HRMS, [Mn(III)(bpmcn)(HFIP-H)(OAc)]⁺ Observed m/z 605.1737; theoretical 605.1753
HRMS, [Mn(III)(bpmcn)(HFIP-H)(OH)]⁺ Observed m/z 563.1628; theoretical 563.1647
HRMS, [Mn(III)(bpmcn)(HFIP-H)(para-propylphenolate)]⁺ Observed m/z 681.2410 in the main paper and CID report and 681.2412 in the spectrum annotation; theoretical 681.2430; based solely on the m/z ratio, the two isomeric complexes could not be distinguished
CID, mass-selected m/z 681.2410 Exclusive elimination of C₃H₇-C₆H₄-O˙, loss 135, and formation of [Mn(III)(bpmcn)(HFIP-H)]⁺ at m/z 546.1600, theoretical 546.1620
HRMS non-detection A signal corresponding to a manganese complex comprising two propylphenolate moieties was not identified
Main, p. 10; SI, pp. 19–20
Complex 1a, acetic acid, H₂O₂ and propylbenzene in HFIP after 4 min
HRMS conditions Total flow 25 µL min⁻¹; 1a 0.3 mM; acetic acid 1.00 mM; H₂O₂ 2.2 mM; propylbenzene 0.5 mM; all ingredients mixed for 4 min before injection
HRMS, [Mn(II)(bpmcn)(OAc)]⁺ Observed m/z 438.1793; theoretical 438.1822
HRMS, [Mn(III)(bpmcn)(HFIP-H)(F)]⁺ Observed m/z 565.1579; theoretical 565.1604
HRMS, [Mn(III)(bpmcn)(HFIP-H)₂]⁺ Observed m/z 713.1526 in the spectrum annotation and 713.1536 in the accompanying text; theoretical 713.1552
HRMS, [Mn(IV)(bpmcn)(2,2′-bi(para-propylphenolate))]²⁺ Observed m/z 323.6562 in the spectrum annotation and 323.6565 for the mass-selected ion; theoretical 323.6573
CID, mass-selected m/z 323.6565 Loss 134.0671 (z = 2), 2,2′-bi(para-propylphenolate), theoretical m/z 134.0750; formation of [Mn(bpmcn)]²⁺ at m/z 189.5894, theoretical 189.5841
Main, pp. 10–11; SI, pp. 20–21
Complex 1a, increased acetic acid and H₂O₂, and propylbenzene in HFIP after 5 min
HRMS conditions Total flow 25 µL min⁻¹; 1a 0.3 mM; acetic acid 1.00 mM; H₂O₂ 2.2 mM; propylbenzene 0.5 mM
HRMS, [Mn(II)(bpmcn)(OAc)]⁺ Observed m/z 438.1795 in the spectrum annotation and 438.1796 in the accompanying text; theoretical 438.1822
HRMS, [Mn(III)(bpmcn)(HFIP-H)(OAc)]⁺ Observed m/z 605.1735 in the spectrum annotation and 605.1737 in the accompanying text; theoretical 605.1753
HRMS, [Mn(III)(bpmcn)(HFIP-H)₂]⁺ Observed m/z 713.1528; theoretical 713.1552
HRMS, [Mn(IV)(bpmcn)(2,2′-bi(para-propylphenolate))]²⁺ Observed m/z 323.6563 in the spectrum annotation and 323.6565 for the mass-selected ion; theoretical 323.6573
CID, mass-selected m/z 323.6565 Loss 134.0671 (z = 2), 2,2′-bi(para-propylphenolate); formation of [Mn(bpmcn)]²⁺ at m/z 189.5894, theoretical 189.5841
Main, p. 11; SI, p. 22
Complex 1a catalytic reaction with acetic acid in HFIP, ion overview
HRMS, [Mn(II)(bpmcn)(HFIP-H)]⁺ Observed m/z 546.1599; theoretical 546.1620; HFIP-H = 1,1,1,3,3,3-hexafluoropropan-2-olate
HRMS non-detection The protonated ligand at m/z 325.2375 was not detected when acetic acid was used as the additive
Main, p. 12; SI, pp. 19, 23
Complex 1a catalytic reaction with and without para-cresol
HRMS, [Mn(III)(bpmcn)(HFIP-H)(para-propylphenolate)]⁺ (m/z 681.2410; para-cresol 2.66 equiv. relative to 1a in the starting mixture) Relative intensity decreased when para-cresol was present in the starting mixture
Main, pp. 11–12; SI, p. 27
Complex 1a catalytic reaction with dichloroacetic acid in HFIP
HRMS conditions 1a 0.375 mM; dichloroacetic acid 2 equiv.; HFIP
HRMS, [Mn(II)(bpmcn)(2,2-dichloroacetate)]⁺ Observed m/z 506.1013; theoretical 506.1042
HRMS, protonated ligand Observed m/z 325.2375; theoretical 323.2386
HRMS, m/z 522.0967 Could potentially correspond to [Mn(IV)(bpmcn)(O)(C₂HCl₂O₂)]⁺, theoretical 522.0991, or a Mn(II) species with peroxy acid formed from CHCl₂COOH
HRMS, [Mn(II)(bpmcn)(OTf)]⁺ Observed m/z 528.1183
HRMS non-detection with dichloroacetic acid Phenolate-bound manganese species were not detected
Main, p. 12; SI, p. 24
Complex 1b
HRMS conditions 1b 0.75 mM
HRMS, [Mn(II)(OTf)(tipsbpmcn)]⁺ Observed m/z 840.3881 in the spectrum annotation and 840.3880 in the figure caption; theoretical 840.3883
HRMS, [Mn(II)(HFIP-H)(tipsbpmcn)]⁺ Observed m/z 858.4292; theoretical 858.4295; HFIP-H = 1,1,1,3,3,3-hexafluoropropan-2-olate
SI, pp. 19, 25–26
Complex 1b catalytic reaction with acetic acid after 10 min
HRMS conditions H₂O₂ 11 mM in HFIP; propylbenzene 3.3 mM in HFIP; acetic acid 6.7 mM in HFIP; 1b stock 0.75 mM; 1000 µL 1b solution and 500 µL of each reagent solution added by syringe pumps over 1 min; spectrum after 10 min
HRMS, [Mn(II)(OAc)(tipsbpmcn)]⁺ Observed m/z 750.4507 in the spectrum annotation and 750.4490 in the figure caption and ion overview; theoretical 750.4496
HRMS, [Mn(III)(tipsbpmcn)(HFIP-H)(OTf)]⁺ Observed m/z 1007.3828 in the spectrum annotation and 1007.382 in the ion overview; theoretical 1007.381
HRMS, [Mn(tipsbpmcn)(HFIP-H)₂]⁺ Observed m/z 1025.422; theoretical 1025.423
HRMS, [Mn(IV)(2,2′-bi(para-propylphenolate))(tipsbpmcn)]²⁺ Observed m/z 479.7915; theoretical 479.7908
SI, pp. 25–27
[Mn(Cl)₂(bpmcn)]
Identifier 2a
ESI-MS calcd. m/z for 2a [Mn(II)(L)(Cl)]⁺: 414.1, found 414.0
FT-IR (ATR), ν (cm⁻¹; w = weak, m = medium, o = strong) 2935 (m), 1601 (o), 1572 (m), 1479 (m), 1439 (m), 1371 (m), 1310 (o), 1257 (o), 766 (o)
Single-crystal XRD, formula and formula weight C₂₀H₂₈Cl₂MnN₄; Fw = 450.30
Single-crystal XRD, crystal Colourless block, 0.27 × 0.26 × 0.15 mm³
Single-crystal XRD, crystal system and space group Tetragonal, P4₃2₁2 (no. 96)
Single-crystal XRD, unit cell a = b = 9.18005(18), c = 23.8700(5) Å; V = 2011.61(9) ų; Z = 4; Dₓ = 1.487 g cm⁻³; μ = 0.94 mm⁻¹
Single-crystal XRD, data collection λ = 0.71073 Å; 150(2) K; (sin θ/λ)ₘₐₓ = 0.65 Å⁻¹; absorption-correction range 0.69–0.75
Single-crystal XRD, reflections 17508 measured, 2303 unique, 2162 observed [I>2σ(I)]; Rᵢₙₜ = 0.032
Single-crystal XRD, refinement 125 parameters, no restraints; R₁/wR₂ [I>2σ(I)] = 0.0197/0.0486; R₁/wR₂ [all reflections] = 0.0217/0.0497; S = 1.046; Flack x = 0.009(19); residual electron density −0.14 to 0.24 e Å⁻³
CV (CH₃CN, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺) OCP = −0.093 V; reversible Mn(II)/Mn(III) redox couple, Eₚ,ₐ = 0.37 V, iₚ,ₐ/iₚ,꜀ = 1.04, ΔEₚ = 150 mV
Main, p. 17; SI, pp. 3, 28, 31, 36, 46
[Mn(OAc)₂(bpmcn)]
Identifier 2b
ESI-MS calcd. m/z for 2b [Mn(II)(L)(OAc)]⁺: 438.18, found 437.9
ESI-MS (CH₃CN) Theoretical m/z = 438.1; experimental m/z = 437.4
FT-IR (ATR), ν (cm⁻¹; w = weak, m = medium, o = strong) 2934 (m), 1621 (m), 1591 (m), 1569 (m), 1440 (m), 1376 (o), 1324 (o), 1306 (m)
Single-crystal XRD, formula and formula weight C₂₄H₃₄MnN₄O₄·CH₃CN; Fw = 538.54
Single-crystal XRD, crystal Colourless block, 0.43 × 0.18 × 0.16 mm³
Single-crystal XRD, crystal system and space group Monoclinic, P2₁/c (no. 14)
Single-crystal XRD, unit cell a = 8.23022(19), b = 12.2525(4), c = 26.6282(8) Å; β = 96.623(2)°; V = 2667.30(13) ų; Z = 4; Dₓ = 1.341 g cm⁻³; μ = 0.54 mm⁻¹
Single-crystal XRD, data collection λ = 0.71073 Å; 150(2) K; (sin θ/λ)ₘₐₓ = 0.65 Å⁻¹; absorption-correction range 0.66–0.75
Single-crystal XRD, reflections 50193 measured, 6126 unique, 5205 observed [I>2σ(I)]; Rᵢₙₜ = 0.034
Single-crystal XRD, refinement One acetate ligand refined with a disorder model; 343 parameters, 62 restraints; R₁/wR₂ [I>2σ(I)] = 0.0324/0.0857; R₁/wR₂ [all reflections] = 0.0393/0.0886; S = 1.086; residual electron density −0.30 to 0.65 e Å⁻³
CV (CH₃CN, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺) OCP = −0.275 V
SI, pp. 3, 29, 31–32, 36, 47
[Mn(O-C₆H₄-Me)₂(bpmcn)]
Identifier 2c
ESI-MS calcd. m/z for C₃₄H₄₂MnN₄O₂ [Mn(II)(L)(OC₆H₄-Me)]⁺: 486.2, found 485.4
FT-IR (ATR), ν (cm⁻¹; w = weak, m = medium, o = strong) 2935 (m), 1601 (o), 1506 (o), 1499 (o), 1441 (m), 1311 (m), 1162 (m), 1098 (m), 825 (o), 760 (o)
Single-crystal XRD, formula and formula weight C₃₄H₄₂MnN₄O₂·CH₂Cl₂; Fw = 678.58
Single-crystal XRD, crystal Pale yellow plate, 0.62 × 0.26 × 0.07 mm³
Single-crystal XRD, crystal system and space group Monoclinic, P2₁/c (no. 14)
Single-crystal XRD, unit cell a = 9.2909(7), b = 14.7137(8), c = 25.2822(13) Å; β = 95.377(3)°; V = 3440.9(3) ų; Z = 4; Dₓ = 1.310 g cm⁻³; μ = 0.58 mm⁻¹
Single-crystal XRD, data collection λ = 0.71073 Å; 150(2) K; (sin θ/λ)ₘₐₓ = 0.65 Å⁻¹; twinned with a twofold rotation about hkl = (0,0,1); absorption-correction range 0.54–0.75
Single-crystal XRD, reflections 66384 measured, 8008 unique, 5076 observed [I>2σ(I)]; Rᵢₙₜ = 0.104
Single-crystal XRD, refinement 402 parameters, no restraints; R₁/wR₂ [I>2σ(I)] = 0.0584/0.1223; R₁/wR₂ [all reflections] = 0.1148/0.1428; S = 1.015; BASF = 0.1368(9); residual electron density −0.39 to 0.65 e Å⁻³
CV (CH₃CN, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺; −1.8 to +1.2 V) OCP = −0.629 V; irreversible oxidation events a, Eₚ,ₐ = −0.28 V; b, +0.25 V; c, 0.5 V; d, 0.8 V; events a–d were not coupled to a reduction wave
Main, pp. 16–17; SI, pp. 3, 29, 32, 37, 48
[Mn(O-C₆H₄-NO₂)₂(bpmcn)]
Identifier 2d
ESI-MS calcd. m/z for C₃₂H₃₆MnN₆O₆ [Mn(II)(L)(OC₆H₄-NO₂)(NCCH₃)]⁺: 558.2, found 557.2
ESI-MS (CH₃CN) Theoretical m/z = 557.2; experimental m/z = 558.2
FT-IR (ATR), ν (cm⁻¹; w = weak, m = medium, o = strong) 1581 (o), 1496 (m), 1463 (m), 1251 (m), 1166 (o), 1107 (o), 1025 (m), 855 (o), 644 (o)
Single-crystal XRD, formula and formula weight C₃₂H₃₆MnN₆O₆; Fw = 655.61
Single-crystal XRD, crystal Red needle, 0.38 × 0.10 × 0.07 mm³
Single-crystal XRD, crystal system and space group Orthorhombic, P2₁2₁2₁ (no. 19)
Single-crystal XRD, unit cell a = 13.2755(13), b = 14.1393(14), c = 17.607(2) Å; V = 3304.9(6) ų; Z = 4; Dₓ = 1.318 g cm⁻³; μ = 0.45 mm⁻¹
Single-crystal XRD, data collection λ = 0.71073 Å; 150(2) K; (sin θ/λ)ₘₐₓ = 0.61 Å⁻¹; reflections were smeared out; two orientation matrices related by a 4.1° rotation; absorption-correction range 0.44–0.75
Single-crystal XRD, reflections 36754 measured, 6342 unique, 3722 observed [I>2σ(I)]; Rᵢₙₜ = 0.112
Single-crystal XRD, refinement One pyridine moiety refined with a disorder model; 455 parameters, 116 restraints; R₁/wR₂ [I>2σ(I)] = 0.0866/0.2073; R₁/wR₂ [all reflections] = 0.1553/0.2439; S = 1.054; Flack x = 0.04(3); residual electron density −0.50 to 1.04 e Å⁻³
CV (THF, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺) OCP = −1.28 V
SI, pp. 3, 30, 32–33, 37, 48
[Mn(O-C₆H₄)₂(bpmcn)]
Identifier 2e
ESI-MS calcd. m/z for C₃₂H₃₆MnN₄O₂ [Mn(III)(L)(OC₆H₄)₂]⁺: 563.2, found 562.9
FT-IR (ATR), ν (cm⁻¹; w = weak, m = medium, o = strong) 1586 (m), 1571 (m), 1480 (m), 1436 (o), 1375 (o), 1107 (o), 1300 (m), 1038 (o), 918 (o), 750 (o)
Single-crystal XRD, formula and formula weight C₃₂H₃₆MnN₄O₂; Fw = 563.59
Single-crystal XRD, crystal Yellow block, 0.36 × 0.27 × 0.16 mm³
Single-crystal XRD, crystal system and space group Tetragonal, P4₁2₁2 (no. 92)
Single-crystal XRD, unit cell a = b = 11.53914(8), c = 21.33243(18) Å; V = 2840.45(5) ų; Z = 4; Dₓ = 1.318 g cm⁻³; μ = 0.50 mm⁻¹
Single-crystal XRD, data collection λ = 0.71073 Å; 150(2) K; (sin θ/λ)ₘₐₓ = 0.70 Å⁻¹; absorption-correction range 0.71–0.75
Single-crystal XRD, reflections 68502 measured, 4147 unique, 4010 observed [I>2σ(I)]; Rᵢₙₜ = 0.031
Single-crystal XRD, refinement 178 parameters, no restraints; R₁/wR₂ [I>2σ(I)] = 0.0216/0.0573; R₁/wR₂ [all reflections] = 0.0226/0.0577; S = 1.071; Flack x = −0.005(3); residual electron density −0.19 to 0.24 e Å⁻³
CV (THF, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺) OCP = −1.24 V; two quasi-reversible peaks were observed
Main, p. 17; SI, pp. 3, 30–31, 33, 37, 49
Complex 1a
CV (CH₃CN, 0.1 M [n-Bu₄N]PF₆, 100 mV s⁻¹, room temperature, N₂, vs. Fc/Fc⁺) OCP = 0.28 V
EC-ESI-MS control without triethylamine (100 µM in HFIP, N₂ at 0.2 bar; CV −0.1 to 1 V at 5 mV s⁻¹ and fixed potential 0.5 V) No changes in the spectrum were observed during CV or at the fixed potential
SI, pp. 36, 38
Single-crystal XRD series for complexes 2a–2e
Coordination geometry The manganese ion adopts a distorted octahedral coordination geometry with a typical cis-α conformation; four coordination sites are occupied by nitrogen atoms of the tetradentate aminopyridine and the remaining two by anionic ligands in cis orientation
Single-crystal XRD, deposition numbers CCDC 2559971–2559975
Selected bond length (Å), Mn1-N1/N1/N1/N11/N1 (axial) 2a 2.27; 2b 2.29; 2c 2.28; 2d 2.25; 2e 2.26
Selected bond length (Å), Mn1-N2/N2/N2/N21/N2 (equatorial) 2a 2.38; 2b 2.38; 2c 2.40; 2d 2.37; 2e 2.32
Selected bond length (Å), Mn1-N2/N3/N3/N31/N2 (equatorial) 2a 2.38; 2b 2.35; 2c 2.38; 2d 2.35; 2e 2.32
Selected bond length (Å), Mn1-N1/N4/N4/N41/N1 (axial) 2a 2.27; 2b 2.28; 2c 2.28; 2d 2.25; 2e 2.26
Selected bond length (Å), Mn1-O1/O2/O12/O1 2a –; 2b 2.07; 2c 2.06; 2d 2.10; 2e 2.05
Selected bond length (Å), Mn1-O3A/O1/O13/O1 2a –; 2b 2.08; 2c 2.05; 2d 2.09; 2e 2.05
Selected bond length (Å), Mn1-Cl1 2a 2.45; 2b –; 2c –; 2d –; 2e –
Selected bond angle (°), N1/N1/N1/N11/N1-Mn1-N2/N2/N2/N21/N2 2a 72.76; 2b 73.71; 2c 71.94; 2d 74.29; 2e 74.03
Selected bond angle (°), N2/N3/N3/N31/N2-Mn1-N1/N4/N4/N41/N1 2a 72.76; 2b 72.36; 2c 73.56; 2d 74.95; 2e 74.03
Selected bond angle (°), N2/N2/N2/N21/N2-Mn1-N3/N3/N3/N31/N2 2a 74.26; 2b 75.23; 2c 74.88; 2d 75.48; 2e 77.80
Selected bond angle (°), N2/N2/N2/N21/N2-Mn1-N1/N4/N4/N41/N1 2a 91.83; 2b 91.25; 2c 97.41; 2d 97.20; 2e 96.70
Selected bond angle (°), O1/O2/O12/O1-Mn1-O3A/O1/O13/O1 2a –; 2b 93.19; 2c 113.84; 2d 112.43; 2e 99.12
Selected bond angle (°), O3A/O1/O13/O1-Mn1-N1/N4/N4/N41/N1 2a –; 2b 89.47; 2c 97.15; 2d 92.45; 2e 92.42
Selected bond angle (°), O1/O2/O12/O1-Mn1-N1/N1/N11/N1 2a –; 2b 92.05; 2c 98.94; 2d 96.42; 2e 92.42
Selected bond angle (°), Cl1-Mn1-Cl1 2a 101.56; 2b –; 2c –; 2d –; 2e –
Main, pp. 16, 24; SI, pp. 34–35
Complex 1a, para-cresol and triethylamine electrochemical series
EC-ESI-MS conditions (CH₃CN) Complex 1a, para-cresol 2 equiv. and triethylamine 3 equiv
EC-ESI-MS conditions (HFIP) Complex 1a 0.3 µmol, para-cresol 0.6 µmol (2 equiv.) and triethylamine 2 equiv
EC-ESI-MS, [Mn(III)(bpmcn)(2,2′-bi(para-cresolate))]⁺ Observed m/z 591.2531; theoretical 591.2526; identity further confirmed by the isotopic pattern
Chronoamperometry-EC-ESI-MS (0.4–1.6 V) The m/z 591.2531 peak decomposed with increasing potential; above 1.2 V it was depleted; a corresponding high-valent Mn(IV) species and the oxidation product were not observed
Main, p. 20; SI, pp. 38–40
Complex 1a, 2,2′-dihydroxybiphenyl and triethylamine electrochemical series
EC-ESI-MS conditions (CH₃CN, N₂) Complex 1a, 2,2′-dihydroxybiphenyl 1.5 equiv. and triethylamine 3 equiv
EC-ESI-MS conditions (HFIP) Complex 1a 0.3 µmol, 2,2′-dihydroxybiphenyl 0.45 µmol (1.5 equiv.) and triethylamine 3 equiv
EC-ESI-MS at 0.5 V, [Mn(III)(bpmcn)(2,2′-biphenolate)]⁺ Observed m/z 563.2204; theoretical 563.2213; identity further confirmed by the isotopic pattern
EC-ESI-MS at 0.75 V, [Mn(IV)(bpmcn)(2,2′-biphenolate)]²⁺ Observed as a dominant species at m/z 281.6101; theoretical 281.6104; z = 2; remained stable under these conditions; identity further confirmed by the isotopic pattern
EC-ESI-MS at 1.0 V, m/z 281.6101 The same peak was detected but was less stable
CID of [Mn(IV)(bpmcn)(2,2′-biphenolate)]²⁺ (m/z 281.6100, 15 eV) Product ion m/z 189.5872, loss −92.0229; product ion m/z 198.5913, loss −83.0188
Main, pp. 20–21; SI, pp. 40–43
Mass-selected [Mn(IV)(bpmcn)(2,2′-biphenolate)]²⁺
IRPD (m/z 281.6) Three distinct bands above 1500 cm⁻¹, assigned to aromatic-ring C=C vibrations; two broad bands between 1400 and 1500 cm⁻¹, assigned to C–H deformation bands; many weak, broad bands below 1400 cm⁻¹
VisPD (m/z 281.6) No fragmentation was observed in the visible range
Main, p. 22; SI, p. 44
[Mn(IV)(tipsbpmcn)(2,2′-bi(para-propylphenolate))]²⁺
VisPD, mass-selected ion (m/z 479.8) Broad absorption over the visible range; the experimental spectrum also depends on the wavelength-dependent laser power