CHEMMEDCHEM
FULL PAPERS
4H, H5 and H7 of quinoline of pq), 7.21–7.14 (m, 3H, H5’ of bpy
and H4 of phenyl ring of pq), 7.02–6.93 (m, 3H, H3 of phenyl ring
of bpy-DA-Boc and H6 of quinoline of pq), 6.79 (t, J=7.5 Hz, 2H,
H5 of phenyl ring of pq), 6.52–6.49 (m, 2H, H6 of phenyl ring of
pq), 6.21 (dd, J=8.4, 2.8 Hz, 1H, H4 of phenyl ring of bpy-DA-Boc),
5.76 (d, J=2.4 Hz, 1H, H6 of phenyl ring of bpy-DA-Boc), 4.51 (s,
2H, CH2NH), 3.63 (s, 3H, OCH3), 2.42 (s, 3H, CH3 of bpy), 1.49 ppm
(s, 9H, CH3 of Boc); MS (ESI+): m/z (%): 1022 (100) [MꢁPF6ꢁ]+.
DA-Boc)](PF6). Complex 2a was isolated as brown crystals (170 mg,
88%): H NMR (400 MHz, [D4]methanol, 298 K, TMS): d=8.68 (s, 1H,
1
H3 of bpy), 8.54 (s, 1H, H3’ of bpy), 8.12 (d, J=8,4 Hz, 2H, H3 of
pyridyl ring of ppy), 7.92–7.81 (m, 6H, H5 and H6 of bpy, H4 of pyr-
idyl ring, H3 of phenyl ring of ppy), 7.63 (d, J=5.6 Hz, 1H, H5’ of
bpy), 7.59–7.55 (m, 2H, H6 of pyridyl ring of ppy), 7.37 (d, J=
5.6 Hz, 1H, H6’ of bpy), 7.07–7.00 (m, 4H, H5 of pyridyl ring, H4 of
phenyl ring of ppy), 6.88 (t, J=7.2 Hz, 2H, H5 of phenyl ring of
ppy), 6.72 (d, J=8.4 Hz, 1H, H3 of phenyl ring of bpy-DA), 6.29 (d,
J=7.6 Hz, 2H, H6 of phenyl ring of ppy), 6.16 (dd, J=8.4, 2.4 Hz,
1H, H4 of phenyl ring of bpy-DA), 5.93 (d, J=2.4 Hz, 1H, H6 of
phenyl ring of bpy-DA), 4.61 (s, 2H, CH2NH), 3.56 (s, 3H, OCH3),
2.57 ppm (s, 3H, CH3 of bpy); 13C NMR (100 MHz, [D6]DMSO, 298 K,
TMS): d=21.4, 46.6, 55.4, 98.9, 101.6, 115.7, 120.5, 122.6, 123.9,
124.2, 124.3, 125.5, 126.0, 127.3, 129.6, 129.8, 130.7, 131.5, 137.2,
139.2, 144.2, 149.0, 149.2, 149.6, 150.0, 151.1, 152.0, 153.0, 154.ꢁ9,
[Ir(pqe)2(bpy-DA-Boc)](PF6): The synthetic procedure was per-
formed as described for [Ir(ppy)2(bpy-DA-Boc)](PF6); however, [Ir2-
(pqe)4Cl2] (499 mg, 0.33 mmol) was used instead of [Ir2(pq)4Cl2].
The crude product was purified by column chromatography on
silica gel using n-hexane/EtOAc (1:2, v/v) as the eluent and subse-
quently recrystallized from CH2Cl2/Et2O to afford the complex as
1
deep red crystals (404 mg, 95%): H NMR (400 MHz, [D4]methanol,
298 K, TMS): d=8.78 (s, 1H, H3 of quinoline of pqe), 8.74 (s, 1H, H3
of quinoline of pqe), 8.54 (d, J=8.6 Hz, H5 of quinoline of pqe),
8.49 (d, J=8.8 Hz, 1H, H5 of quinoline of pqe), 8.31 (s, 1H, H3 of
bpy), 8.24–8.18 (m, 3H, H3 of phenyl ring of pqe, H3’ of bpy), 8.08
(d, J=6.0 Hz, 1H, H6 of bpy), 8.02 (d, J=6.0 Hz, 1H, H6’ of bpy),
7.59–7.57 (m, 2H, H8 of quinoline of pqe, H5 of bpy), 7.47–7.34 (m,
4H, H6 and H8 of quinoline of pqe, H5’ of bpy), 7.20 (t, J=7.6 Hz,
1H, H4 of phenyl of pqe), 6.86–6.82 (m, 1H, H7 of quinoline of
pqe), 6.96–6.92 (m, 1H, H7 of quinoline of pqe, H3 of phenyl ring
of bpy-DA-Boc), 6.84 (t, J=7.6 Hz, 2H, H5 of phenyl ring of pqe),
6.55 (dd, J=7.2, 2.4 Hz, 2H, H6 of phenyl ring of pqe), 6.19 (dd, J=
8.4, 2.4 Hz, 1H, H4 of phenyl ring of bpy-DA-Boc), 5.75 (d, J=
2.8 Hz, 1H, H6 of phenyl ring of bpy-DA-Boc), 4.51 (s, 2H, CH2NH),
4.13 (s, 3H, CO2CH3), 4.11(s, 3H, CO2CH3), 3.60 (s, 3H, OCH3), 2.42 (s,
3H, CH3 of bpy), 1.48 ppm (s, 9H, CH3 of Boc); MS (ESI+): m/z (%):
1137 (100) [MꢁPF6ꢁ]+.
155.4, 155.7, 167.3, 167.4 ppm; IR (KBr): n˜ =3421 (NꢁH), 843 (PF6
)
cmꢁ1; MS (ESI+): m/z (%): 822 (100) [MꢁPF6ꢁ]+; Anal. calcd for
IrC41H36N6OPF6·0.5(CH3CH2)2O: C 51.49, H 4.12, N 8.38, found: C
51.39, H 4.10, N 8.52.
[Ir(pq)2(bpy-DA)](PF6) (3a): The synthetic procedure was per-
formed as described for complex 1a; however, [Ir(pq)2(bpy-DA-
Boc)](PF6) (190 mg, 0.17 mmol) was used instead of [Ir(dfppy)2(bpy-
DA-Boc)](PF6). Complex 3a was isolated as reddish brown crystals
(130 mg, 75%): 1H NMR (300 MHz, [D4]methanol, 298 K, TMS): d=
8.35 (d, J=4.8 Hz, 4H, H3 of quinoline and H3 of phenyl ring of
pq), 8.28 (s, 1H, H3 of bpy), 8.15–8.08 (m, 4H, H4 of quinoline of
pq, H3’ and H6 of bpy), 8.03 (d, J=5.7 Hz, 1H, H6’ of bpy), 7.81–
7.76 (m, 2H, H8 of quinoline of pq), 7.52 (d, J=5.4 Hz, 1H, H5 of
bpy), 7.42–7.28 (m, 4H, H5 and H7 of quinoline of pq), 7.21 (d, J=
9.0 Hz, 1H, H5’ of bpy), 7.15–7.10 (m, 2H, H4 of phenyl ring of pq),
7.04–6.86 (m, 2H, H6 of quinoline of pq), 6.78–6.78 (m, 2H, H5 of
phenyl ring of pq), 6.68 (d, J=8.7 Hz, H3 of phenyl ring of bpy-DA),
6.49 (d, J=8.1 Hz, 2H, H6 of phenyl ring of pq), 6.15 (dd, J=8.1,
2.4 Hz, 1H, H4 of phenyl ring of bpy-DA), 5.74 (d, J=2.7 Hz, 1H, H6
of phenyl ring of bpy-DA), 4.46 (s, 2H, CH2NH), 3.56 (s, 3H, OCH3),
2.40 ppm (s, 3H, CH3 of bpy); 13C NMR (100 MHz, [D6]DMSO, 298 K,
TMS): d=21.2, 55.3, 98.9, 101.1, 115.71, 118.7, 123.1, 124.3, 124.6,
125.1, 127.2, 127.9, 128.2, 129.6, 129.8, 131.0, 134.1, 136.8, 140.8,
146.2, 146.3, 147.1, 147.4, 151.7, 152.1, 152.9, 155.0, 155.2, 155.3,
170.2, 170.3 ppm; IR (KBr): n˜ =3448 cmꢁ1 (NꢁH), 845 (PF6ꢁ); MS
(ESI+): m/z (%): 922 (100) [MꢁPF6ꢁ]+; Anal. calcd for
IrC49H40N6OPF6·H2O·(CH3CH2)2O: C 54.96, H 4.53, N 7.26, found: C
54.97, H 4.57, N 7.45.
[Ir(dfppy)2(bpy-DA)](PF6) (1a): TFA (1 mL) was slowly added to
a CH2Cl2 solution (10 mL) of [Ir(dfppy)2(bpy-DA-Boc)](PF6) (196 mg,
0.17 mmol), and the resultant mixture was stirred in the dark for
2 h. The solution was neutralized by addition of NH4OH. The mix-
ture was extracted with CH2Cl2 (2ꢁ100 mL). The combined organic
layer was washed with saturated aq NaCl (50 mL), dried over
MgSO4, and evaporated to dryness. The residual solid was dis-
solved in CH2Cl2/MeOH (30 mL, 1:1, v/v) containing KPF6 (34.9 mg,
0.19 mmol) and stirred for 2 h. The solvent was removed in vacuo
and the solid was recrystallized from CH2Cl2/Et2O yielding complex
1a as light brown crystals (146 mg, 82%): 1H NMR (400 MHz,
[D4]methanol, 298 K, TMS): d=8.71 (s, 1H, H3 of bpy), 8.59 (s, 1H,
H3’ of bpy), 8.36 (d, J=8.7 Hz, 2H, H6 of pyridyl ring of dfppy),
7.98–7.91 (m, 3H, H5 of pyridyl ring of dfppy and H6 of bpy), 7.84
(d, J=5.1 Hz, 1H, H6’ of bpy), 7.68–7.62 (m, 3H, H3 of pyridyl ring
of dfppy, H5 of bpy), 7.44 (d, J=5.1 Hz, 1H, H5’ of bpy), 7.14–7.10
(m, 2H, H4 of pyridyl ring of dfppy), 6.73–6.65 (m, 3H, H3 of
phenyl ring of bpy-DA, H6 of phenyl ring of dfppy), 6.15 (dd, J=
8.4, 2.7 Hz, 1H, H4 of phenyl ring of bpy-DA), 5.90 (d, J=2.7 Hz,
1H, H6 of phenyl ring of bpy-DA), 5.72–5.68 (m, 2H, H4 of phenyl
ring of dfppy), 4.63, (s, 2H, CH2NH), 3.50 (s, 3H, OCH3), 2.58 ppm (s,
3H, CH3 of bpy); 13C NMR (100 MHz, [D6]DMSO, 298 K, TMS): d=
21.4, 46.3, 55.4, 98.9, 99.4, 101.5, 113.6, 123.7, 123.9, 124.1, 124.9,
126.32, 127.7, 128.0, 130.1, 140.5, 149.8, 149.9, 150.5, 152.7, 155.2,
155.3, 155.4, 155.5, 159.9, 162.1, 163.2, 163.3, 164.5 ppm; IR (KBr):
n˜ =3423 cmꢁ1 (NꢁH), 845 (PF6ꢁ); MS (ESI+): m/z (%): 894 (100)
[MꢁPF6ꢁ]+; Anal. calcd for IrC41H32N6OPF10·CH3OH: C 47.15, H 3.39,
N 7.85, found: C 47.38, H 3.63, N 7.72.
[Ir(pqe)2(bpy-DA)](PF6) (4a): The synthetic procedure was per-
formed as described for complex 1a; however, [Ir(pqe)2(bpy-DA-
Boc)](PF6) (404 mg, 0.32 mmol) was used instead of [Ir(dfppy)2(bpy-
DA-Boc)](PF6). Complex 4a was isolated as a brown solid (334 mg,
1
90%): H NMR (400 MHz, [D4]methanol, 298 K, TMS): d=8.87 (s, 1H,
H3 of quinoline of pqe), 8.74 (s, 1H, H3 of quinoline of pqe), 8.55
(d, J=8.4 Hz, 1H, H5 of quinoline of pqe), 8.49 (d, J=8.4 Hz, 1H,
H5 of quinoline of pqe), 8.30 (s, 1H, H3 of bpy), 8.23 (t, J=6.8 Hz,
H3 of phenyl ring of pqe), 8.13 (s, 1H, H3’ of bpy), 8.09 (d, J=
5.6 Hz, 1H, H6 of bpy), 8.04 (d, J=5.6 Hz, 1H, H6’ of bpy), 7.60–
7.58 (m, 2H, H8 of quinoline of pqe, H5 of bpy), 7.48–7.34 (m, 4H,
H6 and H8 of quinoline of pqe, H5’ of bpy), 7.12 (t, J=7.2 Hz, 2H,
H4 of phenyl ring of pqe), 7.10–7.06 (m, 1H, H7 of quinoline of
pqe), 6.93–6.83 (m, 3H, H7 of quinolone, H5 of phenyl ring of pqe),
6.69 (d, J=8.4 Hz, 1H, H3 of phenyl ring of bpy-DA), 6.55 (d, J=
7.6 Hz, 2H, H6 of phenyl ring of pqe), 6.15 (dd, J=8.4, 2.4 Hz, 1H,
H4 of phenyl ring of bpy-DA), 5.76 (d, J=2.8 Hz, 1H, H6 of phenyl
ring of bpy-DA), 4.49 (s, 2H, CH2NH), 4.13 (s, 3H, CO2CH3), 4.12 (s,
[Ir(ppy)2(bpy-DA)](PF6) (2a): The synthetic procedure was per-
formed as described for complex 1a; however, [Ir(ppy)2(bpy-DA-
Boc)](PF6) (210 mg, 0.20 mmol) was used instead of [Ir(dfppy)2(bpy-
ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemMedChem 2014, 9, 1316 – 1329 1325