S. Harringer, et al.
Inorganica Chimica Acta 513 (2020) 119919
3
3
3
methanol (10 mL). In order to deprotonate the ligand, the solution was
stirred under argon atmosphere at RT for 20 min. The respective di-
meric metal precursor (0.91 eq.) was added and the resulting dark
colored mixture was stirred at RT or 40 °C for 5–30 min (depending on
the complex). Afterwards, the solvent was evaporated under reduced
pressure and the crude product was dissolved in dichloromethane. In
order to remove by-products, the solution was filtrated and the filtrate
was concentrated in vacuo. Precipitation or crystallization from DCM/
EtOAc afforded the desired products in moderate to good yields
2H, Hc), 5.93 (d, J (H,H) = 6 Hz, 2H, Hc), 6.08 (d, J (H,H) = 6 Hz,
3
2H, Hd), 7.38 (d, J (H,H) = 6 Hz, 2H, H6), 7.54 (d, J (H,H) = 6 Hz,
1
3
2H, H5) ppm; C NMR (125.75 MHz, D O, 25 °C): δ = 12.8 (C1), 17.9
2
(Ca), 21.3 (Cg), 22.0 (Cg), 30.3 (Cf), 44.7 (C7), 72.2 (Cc), 75.4 (Cd),
75.5 (Cc), 78.0(Cd), 94.4 (Cb), 98.8 (Ce), 128.1 (C5), 129.2 (C6), 136.8
(C2), 142.3 (C4), 172.7 (C3) ppm.
2.3.3. Preparation of chlorido[1,2-dimethyl-3-oxo-κO-pyridine-4(1H)-
5
selonato-κSe](η -1,2,3,4,5-pentamethylcyclopentadienyl)rhodium(III) (5a)
(40–73%).
For the synthesis of complexes 3b, 4b, and 6b please see the re-
spective section in the electronic supporting information.
The synthesis was performed according to the general complexation
protocol using ligand 2a (50 mg, 0.247 mmol, 1 equiv), sodium methoxide
5
(16 mg, 0.297 mmol, 1.2 equiv) and bis[dichlorido(η -1,2,3,4,5-penta-
methyl-cyclopentadienyl)rhodium(III)] (69 mg, 0.111 mmol, 0.9 equiv) and
a reaction time of 2.0 h. The product was isolated as a red solid. Yield:
2
.3.1. Preparation of chlorido[1,2-dimethyl-3-oxo-κO-pyridine-4(1H)-
6
+
+
selonato-κSe](η -p-cymene)-ruthenium(II) (3a)
50 mg (43%). ESI-HR-MS m/z found (calculated): [M] 440.0002
The synthesis was performed according to the general complexation
protocol using ligand 2a (106 mg, 0.527 mmol, 1 equiv), sodium
(439.9995). Elemental analysis calcd (%) for C17
H
23ClNORhSe·2H O: C
2
40.06, H 5.14, N 2.75; found: C 40.28, H 5.51, N 2.76.
6
1
methoxide (31 mg, 0.580 mmol, 1.1 equiv) and bis[dichlorido(η -p-
Monomer 5a: H NMR (500.10 MHz, d
6
-DMSO, 25 °C): δ = 1.71 (s,
cymene)ruthenium(II)] (161 mg, 0.263 mmol, 0.90 equiv) and a reac-
tion time of 5 min. The product was isolated as red crystals. Yield:
15H, CH , Cp*), 2.46 (s, 3H, H1), 3.88 (s, 3H, H7), 7.48–7.55 (m, 2H,
3
13
H5, H6) ppm; C NMR (125.75 MHz, d
6
-DMSO, 25 °C): δ = 8.7 (CH ,
3
+
+
1
20 mg (48%). ESI-HR-MS m/z found (calculated): [M] 437.9912
Cp*), 11.9 (C1), 44.7 (C7), 96.3 (C, Cp*), 124.6 (C5), 128.9 (C6), 136.0
(
437.9913). Elemental analysis calcd (%) for C17
H
22ClNORuSe·1.5 H
2
O:
(C2), 141.4 (C4), 169.8 (C3) ppm.
C 40.93, H 5.05, N 2.81; found: C 40.83, H 4.96, N 2.93.
Dimer 5a*(trace isomeric mixtures have been observed in the D
2
O
1
1
Monomer 3a: H NMR (500.10 MHz, d
6
-DMSO, 25 °C): δ = 1.18 (d,
NMR): H NMR (500.10 MHz, D
2
O, 25 °C): δ = 1.18 (s, 15H, CH
3
, Cp*),
3
3
J (H,H) = 7 Hz, 3H, Hg), 2.12 (s, 3H, H1), 2.42 (s, 3H, Ha), 2.64–2.72
2.59 (s, 3H, H1), 3.97 (s, 3H, H7), 7.55 (d, J (H,H) = 6 Hz, 1H, H5),
3
3
3
13
(
m, J (H,H) = 7 Hz, 1H, Hf), 3.86 (s, 3H, H7), 5.86 (d,
J
7.75 (d, J (H,H) = 6 Hz, 1H, H6) ppm; C NMR (125.75 MHz, D O,
2
3
(
H,H) = 6 Hz, 2H, Hd), 6.03 (d, J (H,H) = 6 Hz, 2H, Hc), 7.50 (s, 2H,
25 °C): δ = 7.5 (CH3, Cp*), 13.4 (C1), 45.4 (C7), 96.2 (C, Cp*), 127.7
(C5), 129.8 (C6), 141.8 (C2), 144.0 (C4), 169.9 (C3) ppm.
1
3
H5, H6) ppm; C NMR (125.75 MHz, d
6
-DMSO, 25 °C): δ = 12.3 (C1),
1
7.7 (Ca), 22.2 (Cg), 30.4 (Cf), 43.8 (C7), 82.4 (Cd), 82.9 (Cd), 86.9
(
(
Cc), 88.4 (Cc), 102.4 (Cb), 106.3 (Ce), 124.0 (C5), 128.8 (C6), 138.8
C2), 150.1 (C4), 167.9 (C3) ppm.
2.3.4. Preparation of chlorido[1,2-dimethyl-3-oxo-κO-pyridine-4(1H)-
5
selonato-κSe](η -1,2,3,4,5-pentamethylcyclopentadienyl)iridium(III) (6a)
Dimer 3a* (isomeric mixtures have been observed in the D
2
O NMR
The synthesis was performed according to the general complexation
1
3
in a 1:3 ratio): H NMR (500.10 MHz, D
2
O, 25 °C): δ = 1.04 (d,
J
protocol using ligand 2a (50 mg, 0.247 mmol, 1 equiv), sodium methoxide
3
5
(
H,H) = 7 Hz, 6H, Hg), 1.16 (d, J(H,H) = 7 Hz, 6H, Hg), 2.16 (s, 6H,
(16 mg, 0.297 mmol, 1.2 equiv) and bis[dichlorido(η -1,2,3,4,5-penta-
3
H1), 2.29 (s, 6H, Ha), 2.70–2.73 (m, J (H,H) = 7 Hz, 2H, Hf), 3.88 (s,
methyl-cyclopentadienyl)iridium(III)] (78 mg, 0.0973 mmol, 0.9 equiv) and
a reaction time of 25 min. The product was isolated as orange crystals.
3
3
6
2
2
2
H, H7), 5.42 (d, J (H,H) = 6 Hz, 2H, Hd), 5.50 (d, J (H,H) = 6 Hz,
3
3
+
+
H, Hc), 5.65 (d, J (H,H) = 6 Hz, 2H, Hc), 5.81 (d, J (H,H) = 6 Hz,
Yield: 102 mg (74%). ESI-HR-MS m/z found (calculated): [M] 530.0559
3
3
H, Hd), 7.33 (d, J (H,H) = 6 Hz, 2H, H5), 7.42 (d, J (H,H) = 6 Hz,
(530.0568). Elemental analysis calcd (%) for C17
H
23ClIrNOSe·0.7 H O: C
2
1
3
H, H6) ppm; C NMR (125.75 MHz, D
2
O, 25 °C): δ = 12.6 (C1), 17.8
35.47, H 4.10, N 2.43; found: C 35.71, H 4.31, N 2.62.
1
(
Ca), 21.0 (Cg), 21.8 (Cg), 30.2 (Cf), 44.8 (C7), 79.9 (Cd), 83.5 (Cd),
Monomer 6a: H NMR (500.10 MHz, d
6
-DMSO, 25 °C): δ = 1.65 (s,
1
3
8
1
4.1 (Cc), 85.5 (Cc), 101.4 (Cb), 106.6 (Ce), 126.1 (C5), 128.4 (C6),
37.0 (C2), 141.9 (C4), 171.5 (C3) ppm.
15H, CH
3
, Cp*), 3.58 (s, 3H, H7), 7.50–7.54 (m, 2H, H5, H6) ppm;
C
NMR (125.75 MHz, d
6
-DMSO, 25 °C): δ = 8.4 (CH3,Cp*), 12.7 (C1), 43.8
(
C7), 92.1 (C, Cp*), 95.1 (C, Cp*), 124.3 (C5), 129.8 (C6), 135.0 (C2),
2
.3.2. Preparation of chlorido[1,2-dimethyl-3-(oxo-κO)-pyridine-4(1H)-
139.1 (C4), 168.5 (C3) ppm. H1 signal under DMSO peak
6
1
selonato-κSe](η -p-cymene)osmium(II) (4a)
Dimer 6a*: H NMR (500.10 MHz, D
2
O, 25 °C): δ = 1.25 (s, 15H,
The synthesis was performed according to the general complexation
CH
3
, Cp*), 1.65 (s, 15H, CH
3
, Cp*), 2.12 (s, 3H, H1), 2.75 (s, 3H, H1),
3
3
protocol using 2a (112 mg, 0.554 mmol, 1 equiv), sodium methoxide
3.96 (s, 3H, H7), 4.06 (s, 3H, H7), 7.38 (d, J (H,H) = 6 Hz, 1H, H5),
6
3
(
33 mg, 0.610 mmol, 1.1 equiv) and bis[dichlorido(η -p-cymene)os-
7.48 (d, J (H,H) = 6 Hz, 1H, H5), 7.70 (d, J (H,H) = 6 Hz, 1H, H6)
3 13
mium(II)] (217 mg, 0.277 mmol, 1 equiv) and a reaction time of
0 min. The product was isolated as an orange solid. Yield: 124 mg
ppm, 7.83 (d, J (H,H) = 6 Hz, 1H, H6) ppm; C NMR (125.75 MHz,
1
D O, 25 °C): δ = 7.3 (CH3,Cp*), 7.8 (CH3,Cp*), 12.1 (C1), 13.4 (C1), 44.6
2
-
-
(
40%). ESI-HR-MS m/z found (calculated): [M] 526.0451 (526.0463).
(C7), 45.4 (C7), 89.5 (CCp*), 90.2 (CCp*), 126.9 (C5), 127.5 (C5), 128.6
(C6), 130.8 (C6), 134.7 (C2), 140.8 (C2), 142.0 (C4), 144.1 (C4), 170.3
(C3), 171.1 (C3) ppm.
Elemental analysis calcd (%) for C17
H
22ClNOOsSe·H
2
O: C 35.26, H
4
.18, N 2.42; found: C 35.38, H 4.21, N 2.25.
1
Monomer 4a: H NMR (500.10 MHz, d
6
-DMSO, 25 °C): δ = 1.20 (d,
3
J(H,H) = 7 Hz, 6H, Hg), 2.21 (s, 3H, Ha), 2.47 (s, 3H, H1), 2.60–2.70
2.4. Experimental procedure for stability investigations via UV/Vis
3
3
3
(
(
(
m, J (H,H) = 7 Hz, 1H, Hf), 3.88 (s, 3H, H7), 5.97 (d,
J
3
H,H) = 5 Hz, 2H, Hc), 6.15 (d, J (H,H) = 5 Hz, 2H, Hd), 7.55 (d, J
UV/Vis spectra were recorded to investigate complex’ stability in
PBS buffered solution at a pH of 7.6. Solutions were prepared via di-
lution of a stock solution (10 mM complex in DMSO) with PBS buffer
until an absorption around 1.0 was reached in the resulting spectra.
3
13
H,H) = 6 Hz, 1H, H6), 7.60 (d, J (H,H) = 6 Hz, 1H, H5) ppm;
C
NMR (125.75 MHz, d
6
-DMSO, 25 °C): δ = 12.4 (C1), 17.7 (Ca), 22.5
(
Cg), 30.4 (Cf), 43.7 (C7), 78.9 (Cc), 81.0 (Cd), 95.1 (Cb), 98.4 (Ce),
1
23.6 (C5), 129.6 (C6), 138.5 (C2), 151.0 (C4), 169.1 (C3) ppm.
Dimer 4a*(trace isomeric mixtures have been observed in the D
2
O
3
2.5. Experimental procedure for stability investigations in aqueous solution
via UHPLC runs
1
NMR): H NMR (500.10 MHz, D
2
O, 25 °C): δ = 1.03 (d,
J
3
(
H,H) = 6 Hz, 6H, Hg), 1.18 (d, J (H,H) = 6 Hz, 6H, Hg), 2.27 (s, 6H,
3
H1), 2.34 (s, 6H, Ha), 2.59–2.67 (m, J (H,H) = 7 Hz, 2H, Hf), 3.90 (s,
Stock solutions containing the desired complex in DMSO (5 mM)
were diluted with phosphate buffer to a final concentration of 50 µM
3
3
6
H, H7), 5.74 (d, J (H,H) = 6 Hz, 2H, Hd), 5.82 (d, J (H,H) = 6 Hz,
3