Compound characterization data — Natasha R. Cornejo et al., 2026

Natasha R. Cornejo et al. “Broadening the view of aryl diazonium ion reactivity with proteins and DNA.” ChemRxiv (2026). https://doi.org/10.26434/chemrxiv.15004493/v2

Protein competition experiments with p-Br, m-yne, and H ADI, equine myoglobin (EM), human lysozyme (HL), and ribonuclease A (RA)
MS/MS reporting	Each experiment was run in triplicate; only significant modifications are shown
MS/MS, ribonuclease A	No ADI modifications were observed
MS/MS, m-yne ADI	Products consistent with arylation were observed on EM; HL-Y63-Az and EM-Y146-Ar were detected on different proteins; EM-Y146 was observed exclusively in its arylated form; EM displayed robust azo labeling at H24; an m-yne azo adduct was also observed at HL-Y63
MS/MS arylation qualifier	Arylation during electrospray ionization cannot be completely excluded
MS/MS, H ADI	HL Y38 and Y63 were modified by the unsubstituted ADI; HL H96 remained unlabeled
MS/MS, p-Br ADI	The only Br-derived modification detected corresponded to an arylation at EM-H64
MS/MS, peptide modification count	No peptide was observed with more than one modification

(E)-4-methyl-2-((4-nitrophenyl)diazenyl)phenol
¹H NMR (500 MHz, CDCl₃)	δ 12.43 (s, 1H), 8.41 – 8.36 (m, 2H), 8.03 – 7.97 (m, 2H), 7.78 (dd, J = 2.3, 1.0 Hz, 1H), 7.25 (d, J = 2.4 Hz, 1H), 6.97 (d, J = 8.5 Hz, 1H), 2.41 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 151.31, 136.74, 134.04, 130.30, 125.40, 123.15, 118.64, 31.34, 20.69
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₃H₁₁N₃O₃ 258.0800; found 258.0873

(E)-4-methyl-2-((4-nitrophenyl)diazenyl)-1H-imidazole
Identifier	p-NO₂ HC2
¹H NMR (400 MHz, DMSO)	δ 13.16 (s, 1H), 8.41 (dd, J = 9.1, 2.1 Hz, 3H), 8.04 – 7.96 (m, 3H), 7.25 (s, 1H), 2.30 (s, 3H), 2.26 (s, 1H)
¹³C NMR (101 MHz, DMSO)	δ 224.80, 155.77, 148.89, 125.23
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₉N₅O₂ 232.0756; found 232.0829

(E)-4-methyl-5-((4-nitrophenyl)diazenyl)-1H-imidazole
Identifier	p-NO₂ HC5
¹H NMR (400 MHz, DMSO)	δ 12.93 (s, 1H), 8.40 – 8.33 (m, 2H), 7.97 – 7.92 (m, 2H), 7.86 (s, 1H), 2.57 (s, 3H)
¹³C NMR (101 MHz, DMSO)	δ 156.75, 147.07, 125.04, 122.54
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₉N₅O₂ 232.0756; found 232.0829

4-methyl-2,5-bis((E)-(4-nitrophenyl)diazenyl)-1H-imidazole
Identifier	p-NO₂ HD
¹H NMR (400 MHz, DMSO)	δ 14.05 (s, 1H), 8.53 – 8.36 (m, 4H), 8.15 – 8.00 (m, 4H), 2.71 (s, 3H)
¹³C NMR (101 MHz, DMSO)	δ 228.78, 218.19, 125.39, 123.03
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₆H₁₂N₈O₄ 381.0892; found 381.10543

(E)-2-((4-bromophenyl)diazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.49 (s, 1H), 7.75 – 7.71 (m, 3H), 7.66 – 7.62 (m, 2H), 7.18 (dd, J = 8.4, 2.3 Hz, 1H), 6.93 (d, J = 8.4 Hz, 1H), 2.38 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 150.39, 149.36, 136.93, 134.61, 132.92, 132.22, 129.28, 125.19, 123.47, 117.81, 20.18
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₃H₁₁BrN₂O m/z: 291.0055; found value 291.0128

(E)-2-((4-bromophenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-Br HC2
¹H NMR (400 MHz, MeOD)	δ 7.88 – 7.78 (m, 2H), 7.78 – 7.66 (m, 2H), 7.12 – 7.04 (m, 1H), 2.33 (s, 3H)
¹³C NMR (101 MHz, MeOD)	δ 133.68, 125.35
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₉BrN₄ m/z: 265.0011; found value 265.0083

(E)-5-((4-bromophenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-Br HC5
¹H NMR (400 MHz, MeOD)	δ 7.78 – 7.73 (m, 2H), 7.71 (s, 1H), 7.67 – 7.62 (m, 2H), 2.59 (s, 3H)
¹³C NMR (101 MHz, MeOD)	δ 133.35, 124.84
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₉BrN₄ m/z: 265.0011; found value 265.0083

2,5-bis((E)-(4-bromophenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-Br HD
¹H NMR (400 MHz, CDCl₃)	δ 7.88 – 7.72 (m, 4H), 7.63 (t, J = 9.6 Hz, 4H), 2.73 (s, 3H)
¹³C NMR (101 MHz, CDCl₃)	δ 132.88, 132.64, 125.08, 124.25, 29.83
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₉BrN₄ m/z: 448.9470; found value 448.9524

(E)-4-((2-hydroxy-5-methylphenyl)diazenyl)benzaldehyde
¹H NMR (500 MHz, CDCl₃)	δ 12.58 (s, 1H), 10.10 (s, 1H), 8.06 – 7.97 (m, 4H), 7.78 (dd, J = 2.3, 1.0 Hz, 1H), 7.23 (dd, J = 8.5, 2.3 Hz, 1H), 6.96 (d, J = 8.4 Hz, 1H), 2.40 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 191.74, 154.56, 151.22, 137.90, 137.78, 136.13, 123.09, 118.53, 31.33, 20.70
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₄H₁₂N₂O₂ m/z: 241.0899; found value 241.0975

(E)-4-((4-methyl-1H-imidazol-2-yl)diazenyl)benzaldehyde
Identifier	p-CHO HC2
¹H NMR (500 MHz, DMSO)	δ 13.03 (s, 1H), 10.09 (s, 1H), 8.09 (d, J = 2.5 Hz, 2H), 7.98 (d, J = 8.6 Hz, 2H), 7.20 (s, 1H), 2.29 (s, 3H), 2.25 (s, 1H)
¹³C NMR (126 MHz, DMSO)	δ 208.65, 130.91, 122.64
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₀N₄O m/z: 214.0855; found value = 215.09724

(E)-4-((4-methyl-1H-imidazol-5-yl)diazenyl)benzaldehyde
Identifier	p-CHO HC5
¹H NMR (500 MHz, DMSO)	δ 10.06 (s, 1H), 8.05 (d, J = 7.5 Hz, 2H), 7.93 (d, J = 8.1 Hz, 2H), 7.78 (s, 1H), 2.58 (s, 3H)
¹³C NMR (126 MHz, DMSO)	δ 130.79, 122.26
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₀N₄O m/z: 214.0885; found value = 215.0972

4,4'-((1E,1'E)-(4-methyl-1H-imidazole-2,5-diyl)bis(diazene-2,1-diyl))dibenzaldehyde
Identifier	p-CHO HD
¹H NMR (500 MHz, DMSO)	δ 10.08 (s, 1H), 10.05 (s, 1H), 8.09 (d, J = 8.1 Hz, 2H), 8.04 (d, J = 8.3 Hz, 2H), 7.99 (d, J = 8.2 Hz, 2H), 7.94 (d, J = 8.2 Hz, 2H), 2.60 (s, 3H)
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₈H₁₄N₆O₂ m/z: 346.1178; found value = 347.1251

3-ethynylbenzenediazonium tetrafluoroborate
¹H NMR (500 MHz, D₂O)	δ 8.69 (t, J = 1.9 Hz, 1H), 8.58 (ddd, J = 8.4, 2.2, 1.1 Hz, 1H), 8.37 (dt, J = 8.0, 1.4 Hz, 1H), 7.97 – 7.93 (m, 1H), 3.89 (s, 1H)
¹³C NMR (126 MHz, D₂O)	δ 144.90, 134.65, 132.02, 83.66

(E)-2-((3-ethynylphenyl)diazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.50 (s, 1H), 7.99 (t, J = 1.8 Hz, 1H), 7.85 (ddd, J = 8.0, 2.1, 1.1 Hz, 1H), 7.75 (dd, J = 2.3, 1.0 Hz, 1H), 7.58 (d, J = 7.6 Hz, 1H), 7.49 (d, J = 7.9 Hz, 1H), 7.18 (dd, J = 8.4, 2.3 Hz, 1H), 6.94 (d, J = 8.4 Hz, 1H), 3.16 (s, 1H), 2.39 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 150.06, 134.73, 133.82, 133.14, 132.46, 118.11, 20.45, 19.66
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₅H₁₂N₂O m/z: 237.0950; found 237.10224

(E)-2-((3-ethynylphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	m-yne-HC2
¹H NMR (400 MHz, MeOD)	δ 7.99 (t, J = 1.8 Hz, 1H), 7.92 (dt, J = 8.0, 1.6 Hz, 1H), 7.62 – 7.49 (m, 2H), 7.12 – 7.05 (m, 1H), 3.63 (s, 1H), 2.34 (s, 3H)
¹³C NMR (101 MHz, MeOD)	δ 127.13, 123.95
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₂H₁₀N₄ 211.0905; found 211.0978

(E)-5-((3-ethynylphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	m-yne HC5
¹H NMR (500 MHz, MeOD)	δ 7.89 (s, 1H), 7.84 (d, J = 7.8 Hz, 1H), 7.72 (s, 1H), 7.53 – 7.45 (m, 2H), 3.58 (s, 1H), 2.61 (s, 3H)
¹³C NMR (126 MHz, MeOD)	δ 132.75, 128.97, 125.00, 123.27, 122.24, 82.35, 77.95
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₂H₁₀N₄ 211.0905; found 211.0978

2,5-bis((E)-(3-ethynylphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	m-yne HD
¹H NMR (500 MHz, DMSO)	δ 7.97 – 7.87 (m, 4H), 7.70 (d, J = 1.5 Hz, 1H), 7.67 (d, J = 7.8 Hz, 1H), 7.59 (dd, J = 5.2, 1.2 Hz, 2H), 4.40 (s, 1H), 4.34 (s, 1H), 2.67 (s, 3H)
¹³C NMR (126 MHz, DMSO)	δ 131.59, 129.98, 125.16, 124.48, 123.14, 82.44, 81.69, 59.80, 48.63, 20.81, 14.12
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₂₀H₁₄N₆ 339.1280; found 339.1353

(E)-4-methyl-2-(phenyldiazenyl)phenol
¹H NMR (500 MHz, CDCl₃)	δ 12.71 (s, 1H), 7.88 – 7.85 (m, 2H), 7.76 (dd, J = 2.2, 1.0 Hz, 1H), 7.52 (dt, J = 10.4, 8.2 Hz, 4H), 7.17 (dd, J = 8.4, 2.3 Hz, 1H), 6.94 (d, J = 8.4 Hz, 1H), 2.39 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 151.04, 150.91, 137.45, 134.69, 133.41, 131.43, 129.74, 129.61, 122.59, 118.26, 20.71
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₃H₁₂N₂O m/z: 213.0950; found value 213.1022

(E)-4-methyl-2-(phenyldiazenyl)-1H-imidazole
Identifier	H HC2
¹H NMR (400 MHz, MeOD)	δ 7.94 – 7.87 (m, 2H), 7.57 – 7.46 (m, 3H), 7.06 – 7.02 (m, 1H), 2.32 (d, J = 0.9 Hz, 3H)
¹³C NMR (101 MHz, MeOD)	δ 152.49, 131.19, 128.94, 122.37
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₁₀N₄ m/z: 187.0905; found value 187.0978

(E)-4-methyl-5-(phenyldiazenyl)-1H-imidazole
Identifier	H HC5
¹H NMR (400 MHz, MeOD)	δ 7.85 (dd, J = 7.6, 1.7 Hz, 2H), 7.70 (s, 1H), 7.49 (dd, J = 8.4, 6.7 Hz, 2H), 7.44 – 7.38 (m, 1H), 2.60 (s, 3H)
¹³C NMR (101 MHz, MeOD)	δ 129.67, 128.72, 121.82
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₀H₁₀N₄ m/z: 187.0905; found value 187.0978

4-methyl-2,5-bis((E)-phenyldiazenyl)-1H-imidazole
Identifier	Bn HD
¹H NMR (400 MHz, CDCl₃)	δ 8.08 – 7.86 (m, 4H), 7.60 – 7.40 (m, 6H), 2.76 (s, 3H)
¹³C NMR (101 MHz, CDCl₃)	δ 181.31, 152.90, 129.38, 122.69, 29.71
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₆H₁₄N₆ m/z: 291.1280; found value 291.1353

(E)-2-((4-(hydroxymethyl)phenyl)diazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.69 (s, 1H), 7.89 – 7.85 (m, 2H), 7.75 (dd, J = 2.3, 0.9 Hz, 1H), 7.54 – 7.50 (m, 2H), 7.18 – 7.15 (m, 1H), 6.94 (d, J = 8.4 Hz, 1H), 4.80 (s, 2H), 2.39 (d, J = 0.7 Hz, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 229.06, 150.62, 144.08, 134.44, 133.13, 127.79, 122.53, 117.99, 29.85, 20.47
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₄H₁₄N₂O₂ m/z: 243.1055; found value 243.1128

(E)-(4-((4-methyl-1H-imidazol-2-yl)diazenyl)phenyl)methanol
Identifier	p-CH₂OH HC2
¹H NMR (400 MHz, MeOD)	δ 7.91 (d, J = 8.4 Hz, 2H), 7.53 (d, J = 8.5 Hz, 2H), 7.04 (d, J = 1.0 Hz, 1H), 4.69 (s, 2H), 2.33 (s, 3H)
¹³C NMR (101 MHz, MeOD)	δ 171.81, 128.59, 123.86, 49.64, 49.42, 49.21, 49.00, 48.79, 48.57, 48.36
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₂N₄O m/z: 217.10839

(E)-4-methyl-2-(p-tolyldiazenyl)phenol
¹H NMR (500 MHz, CDCl₃)	δ 12.74 (s, 1H), 7.79 – 7.75 (m, 2H), 7.74 – 7.71 (m, 1H), 7.33 – 7.29 (m, 2H), 7.15 (dd, J = 8.4, 2.3 Hz, 1H), 6.92 (d, J = 8.4 Hz, 1H), 2.44 (s, 3H), 2.38 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 150.49, 148.69, 141.72, 137.00, 133.88, 132.79, 130.02, 129.12, 122.15, 117.80, 21.53, 20.33
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₄H₁₄N₂O m/z: 227.1106; found value 227.1179

(E)-4-methyl-2-(p-tolyldiazenyl)-1H-imidazole
Identifier	p-Me HC2
¹H NMR (600 MHz, DMSO)	δ 7.75 – 7.71 (m, 2H, H3), 7.38 (d, J = 8.1 Hz, 2H, H5), 7.05 (s, 1H, H4’), 2.39 (s, 3H, H2), 2.25 (s, 2H, H1), 2.22 (s, 1H, H1’)
¹³C NMR (151 MHz, DMSO)	δ 154.12 (C9), 153.68 (C9’), 150.23 (C8), 141.48 (C7’), 141.25 (C7), 140.26 (C6’), 130.56 (C6), 130.10 (C5), 129.86 (C4), 122.15 (C3), 116.67 (C4’), 21.08 (C2), 13.95 (C1’), 10.10 (C1)
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₂N₄ m/z: 201.1062; found value 201.1135

(E)-4-methyl-5-(p-tolyldiazenyl)-1H-imidazole
Identifier	p-Me HC5
¹H NMR (500 MHz, MeOD)	δ 7.74 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 7.9 Hz, 2H), 2.58 (s, 1H), 2.40 (s, 1H)
¹³C NMR (126 MHz, MeOD)	δ 177.66, 141.68, 136.94, 130.67, 123.18, 28.78, 21.37
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₂N₄ m/z: 201.1062; found value 201.1135

4-methyl-2,5-bis((E)-p-tolyldiazenyl)-1H-imidazole
Identifier	p-Me HD
¹H NMR (500 MHz, CDCl₃)	δ 7.93 – 7.90 (m, 3H), 7.79 (d, J = 8.2 Hz, 2H), 7.32 (dd, J = 16.0, 8.0 Hz, 6H), 2.74 (s, 3H), 2.45 (s, 3H), 2.44 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 130.23, 123.81, 122.74, 21.73, 13.11
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₈H₁₈N₆ m/z: 319.1593; found value 319.1666

(E)-2-((4-methoxyphenyl)diazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.68 (s, 1H), 7.87 – 7.82 (m, 2H), 7.70 (dd, J = 2.3, 1.0 Hz, 1H), 7.12 (dd, J = 8.6, 2.3 Hz, 1H), 7.04 – 6.99 (m, 2H), 6.91 (d, J = 8.4 Hz, 1H), 3.90 (s, 3H), 2.38 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 161.99, 150.25, 144.71, 136.83, 133.28, 132.34, 128.95, 123.84, 117.59, 114.43, 55.53, 20.22
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₄H₁₄N₂O₂ m/z: 243.1055; found value 243.1128

(E)-2-((4-methoxyphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-OMe HC2
¹H NMR (500 MHz, CDCl₃)	δ 7.91 (d, J = 8.9 Hz, 2H), 7.03 – 6.94 (m, 3H), 3.89 (s, 3H), 2.36 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 162.64, 146.64, 125.16, 114.54, 55.77. 29.85
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₂N₄O m/z: 217.1011; found value 217.1084

(E)-5-((4-methoxyphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-OMe HC5
¹H NMR (500 MHz, MeOD)	δ 7.86 – 7.80 (m, 2H), 7.65 (s, 1H), 7.05 – 6.99 (m, 2H), 3.86 (s, 3H), 2.56 (s, 3H)
¹³C NMR (126 MHz, MeOD)	δ 213.40, 161.51, 147.26, 135.28, 123.47, 113.83, 54.65, 9.19
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₁H₁₂N₄O m/z: 217.1011; found value 217.1084

2,5-bis((E)-(4-methoxyphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	p-OMe HD
¹H NMR (500 MHz, CDCl₃)	δ 7.99 (d, J = 8.8 Hz, 2H), 7.87 (d, J = 9.0 Hz, 2H), 7.02 (dd, J = 10.9, 8.1 Hz, 4H), 3.91 (s, 3H), 3.90 (s, 3H), 2.71 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 162.08, 125.90, 124.55, 114.77, 114.58, 55.86, 55.77, 29.85, 13.06
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₈H₁₈N₆O₂ m/z: 351.1491; found value 351.1564

(E)-2-(mesityldiazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.81 (s, 1H), 7.73 (dd, J = 2.4, 0.9 Hz, 1H), 7.16 (dd, J = 8.4, 2.3 Hz, 1H), 6.97 (s, 2H), 6.94 (d, J = 8.4 Hz, 1H), 2.43 (s, 6H), 2.39 (s, 3H), 2.34 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 150.33, 139.69, 137.60, 134.17, 133.19, 132.42, 130.83, 129.42, 118.22, 21.53, 20.72, 20.32
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₆H₁₈N₂O m/z: 255.1419; found value 255.1492

(E)-2-(mesityldiazenyl)-4-methyl-1H-imidazole
Identifier	2,4,6-Me₃ HC2
¹H NMR (500 MHz, CDCl₃)	δ 7.64 (s, 1H), 6.92 (s, 2H), 2.59 (s, 3H), 2.37 (s, 6H), 2.31 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 130.09, 21.10, 19.61
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₃H₁₆N₄ m/z: 229.1375; found value: 229.1448

2,5-bis((E)-mesityldiazenyl)-4-methyl-1H-imidazole
Identifier	2,4,6-Me₃ HD
¹H NMR (500 MHz, CDCl₃)	δ 6.94 (s, 4H), 2.56 (s, 3H), 2.37 (s, 12H), 2.31 (s, 6H)
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₂₂H₂₆N₆ m/z: 375.2291; found value = 375.2295

(E)-2-((4-bromo-2,6-dimethylphenyl)diazenyl)-4-methylphenol
¹H NMR (500 MHz, CDCl₃)	δ 12.49 (s, 1H), 7.73 (dd, J = 2.3, 0.9 Hz, 1H), 7.32 (s, 2H), 7.20 (dd, J = 8.4, 2.2 Hz, 1H), 6.95 (d, J = 8.4 Hz, 1H), 2.40 (s, 6H), 2.39 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 149.92, 134.59, 133.68, 133.00, 132.32, 129.32, 117.97, 20.31, 19.52
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₁₅H₁₅BrN₂O m/z: 321.0347; found value 321.0420

(E)-2-((4-bromo-2,6-dimethylphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	4-Br-2,6-Me₂ HC2
¹H NMR (500 MHz, MeOD)	δ 7.71 (s, 1H), 7.27 (s, 2H), 2.55 (s, 3H), 2.31 (s, 6H)
¹³C NMR (126 MHz, MeOD)	δ 131.24, 17.58
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₂₀H₂₀BrN₄ m/z: 293.0323; found value = 293.0396

2,5-bis((E)-(4-bromo-2,6-dimethylphenyl)diazenyl)-4-methyl-1H-imidazole
Identifier	4-Br-2,6-Me₂ HD
¹H NMR (500 MHz, DMSO)	δ 13.34 (s, 1H), 7.48 (s, 2H), 7.40 (s, 2H), 2.60 (s, 3H), 2.40 (s, 6H), 2.31 (s, 6H)
¹³C NMR (126 MHz, DMSO)	δ 131.85, 131.45, 18.78, 18.53
HRMS (ESI)	m/z: [M + H]⁺ calculated for C₂₀H₂₀Br₂N₆ m/z: 503.0096; found value = 503.0189