PdII Complexes with Benzimidazolin-2-ylidene and Phosphane Ligands
131.3, 128.6, 128.3, 125.7, 123.4, 122.9, 122.1, 111.5, 111.2, 111.0
trans-Dibromido[N-(2-methoxyethyl)-NЈ-(2,3,5,6-tetramethyl-
[Ar-C and PPh2(2-py)-C and C6(CH3)5], 71.5 (NCH2CH2OCH3), benzyl)benzimidazolin-2-ylidene](tricyclohexylphosphane)palladium
5 9. 1 (N C H 2 C H 2 OC H 3 ) , 5 1 . 6 [ C H 2 C 6 H ( C H 3 ) 4 ] , 4 9 . 1 (5b): The complex was prepared as described for 3b using 2b and
1
(NCH2CH2OCH3), 20.6 [m-C6H(CH3)4], 16.6 [o-C6H(CH3)4] ppm. PCy3. Yield: 0.80 g, 92.0%. H NMR (400 MHz, CDCl3): δ = 7.48
31P NMR (162.0 MHz, CDCl3): δ = 26.6 ppm. MS (MALDI): m/z
= 771 [M – Br]+. C38H40Br2N3OPPd (851.9): calcd. C 53.57, H
4.73, N 4.93; found C 53.62, H 4.85, N 4.98.
(d, J = 4 Hz, 1 H, Ar-H), 7.11 (t, J = 4.1 Hz, 1 H, Ar-H), 6.85 (t,
J = 4.1 Hz, 1 H, Ar-H), 6.25 (d, J = 4.1 Hz, 1 H, Ar-H), 6.18 [s, 1
H, CH2C6H(CH3)4], 6.06 [s, 2 H, CH2C6H(CH3)4], 4.94 (t, J =
3 Hz, 2 H, NCH2 CH2 OCH3 ), 4.17 (t, J = 3.2 Hz, 2 H,
NCH2CH2OCH3), 3.38 (s, 3 H, NCH2CH2OCH3), 2.54 (m, 3 H,
PCy3-H), 2.33 [s, 6 H, o-C6H(CH3)4], 2.27 [s, 6 H, m-C6H(CH3)4],
2.05–167 (m, 14 H, PCy3-H), 1.30–1.20 (m, 16 H, PCy3-H) ppm.
cis-Dibromido[N,NЈ-bis(pentamethylbenzyl)benzimidazolin-2-ylid-
ene](diphenyl-2-pyridylphosphane)palladium (4c): The complex was
prepared as described for 3a by using 2c and PPh2(2-py). Yield:
1
0.90 g, 93.0%. H NMR (400 MHz, CDCl3): δ = 7.95 [br. m, 4 H,
2
13C NMR (100 MHz, CDCl3): δ = 180.3 (d, JC,P = 174.7 Hz,
PPh2(2-py)-H], 7.45 [d, J = 0.8 Hz, 6 H, PPh2(2-py)-H], 7.13 [s, 1
H, PPh2(2-py)-H], 6.83 [br. m, 3 H, PPh2(2-py)-H], 6.58 (s, 2 H,
Ar-H), 6.50 (d, J = 3.2 Hz, 2 H, Ar-H), 5.81 (d, J = 3.2 Hz, 2 H,
Ar-H), 5.29–5.22 [m, 4 H, CH2C6(CH3)5], 2.27 [s, 12 H, o-C6-
(CH3)5], 2.18 [s, 12 H, m-C6(CH3)5], 2.03 [s, 6 H, p-C6(CH3)5] ppm.
NCN), 135.9, 134.8, 133.0, 128.6, 128.1 122.6, 122.1, 111.6, 111.4,
110.7 [Ar-C and C6H(CH3)4], 71.1 (NCH2CH2OCH3), 59.0
(NCH2CH2OCH3), 51.7 [CH2C6(CH3)5], 47.8 (NCH2CH2OCH3),
1
2
32.2 (d, JP,C = 20.0 Hz, PCy3-C), 30.0 (PCy3-C), 27.9 (d, JP,C
=
1
9.1 Hz, PCy3-C), 26.9, 26.7, 26.1 (PCy3-C), 17.7 [m-C6H(CH3)4],
17.2 [o-C6H(CH3)4] ppm. 31P NMR (162.0 MHz, CDCl3): δ =
21.6 ppm. MS (MALDI): m/z = 789 [M – Br]+. C39H59Br2N2OPPd
(869.10): calcd. C 53.90, H 6.84, N 3.22; found C 53.81, H 6.83, N
3.24.
13C NMR (100 MHz, CDCl3): δ = 173.9 (NCN), 149.6 [d, JP,C
=
3
16.1 Hz, PPh2(2-py)-C], 136.8 [d, JP, C = 9.1 Hz, PPh2(2-py)-C],
136.4, 135.6, 134.9, 133.2, 131.6 [Ar-C and PPh2(2-py)-C and
2
C6(CH3)5], 128.9 [d, JP,C = 10.7 Hz, PPh2(2-py)-C], 127.5, 122.2,
111.4 [Ar-C, PPh2(2-py)-C], 52.3 [CH2C6(CH3)5], 17.6 [p-C6-
(CH3)5], 17.5 [m-C6(CH3)5], 17.0 [o-C6(CH3)5] ppm. 31P NMR
(162.0 MHz, CDCl3): δ = 27.3 ppm. MS (MALDI): m/z = 888 [M –
Br]+. C48H52Br2N3PPd (968.14): calcd. C 59.55, H 5.41, N 4.34;
found C 59.71, H 5.43, N 4.29.
trans-Dibromido[N,NЈ-bis(pentamethylbenzyl)benzimidazolin-2-yl-
idene](tricyclohexylphosphane)palladium (5c): The complex was pre-
pared as described for 3b by using 2c and PCy3. Yield: 0.91 g,
92.0%. 1H NMR (400 MHz, CDCl3): δ = 6.68 (m, 2 H, Ar-H),
6.22 (m, 2 H, Ar-H), 6.18 [s, 4 H, CH2C6(CH3)5], 2.58 (m, 3 H,
PCy3-H), 2.37 [s, 12 H, o-C6(CH3)5], 2.33 [s, 6 H, p-C6(CH3)5], 2.27
[s, 12 H, m-C6(CH3)5], 2.07 (m, 6 H, PCy3-H), 1.83–1.68 (m, 15 H,
PCy3-H), 1.31 (m, 9 H, PCy3-H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 179.6 (d, 2JC,P = 175.4 Hz, NCN), 136.0, 135.7, 135.1,
133.2, 128.6, 122.1, 111.6 [Ar-C and C6(CH3)5], 52.3 [CH2C6-
cis-Dibromido[N,NЈ-bis(2,3,5,6-tetramethylbenzyl)benzimidazolin-2-
ylidene](diphenyl-2-pyridylphosphane)palladium (4d): The complex
was prepared as described for 3a by using 2d and PPh2(2-py). Yield:
1
0.85 g, 90.0%. H NMR (400 MHz, CDCl3): δ = 7.94 [br. m, 4 H,
PPh2(2-py)-H], 7.49 [d, J = 0.7 Hz, 6 H, PPh2(2-py)-H], 7.12 [s, 1
H, PPh2(2-py)-H], 6.90 [br. m, 3 H, PPh2(2-py)-H], 6.53 [s, 2 H,
CH2C6H(CH3)4], 6.50 (d, J = 3.0 Hz, 2 H, Ar-H), 5.83 (d, J =
3.0 Hz, 2 H, Ar-H), 5.27–5.20 [m, 4 H, CH2C6H(CH3)4], 2.25 [s,
12 H, o-C6H(CH3)4], 2.19 [s, 12 H, m-C6(CH3)5] ppm. 13C NMR
1
(CH3)5], 32.6 (d, JP,C = 19.1 Hz, PCy3-C), 30.4 (PCy3-C), 27.9 (d,
2JP,C = 9.9 Hz, PCy3-C), 26.9, 26.7, 26.0 (PCy3-C), 18.5 [p-C6-
(CH3)5], 17.5 [m-C6(CH3)5], 17.1 [o-C6(CH3)5] ppm. 31P NMR
(162.0 MHz, CDCl3): δ = 22.9 ppm. MS (MALDI): m/z = 906 [M –
Br]+. C49H71Br2N2PPd (985.30): calcd. C 59.73, H 7.26, N 2.84;
found C 59.81, H 7.23, N 2.79.
1
(100 MHz, CDCl3): δ = 172.9 (NCN), 149.7 [d, JP,C = 16.0 Hz,
3
PPh2(2-py)-C], 136.3 [d, JP,C = 9.3 Hz, PPh2(2-py)-C], 136.1,
135.2, 134.7, 134.2, 132.0 [Ar-C and PPh2(2-py)-C and C6H-
2
(CH3)4-C], 128.9 [d, JP,C = 10.0 Hz, PPh2(2-py)-C], 127.6, 121.9,
trans-Dibromido[N,NЈ-bis(2,3,5,6-tetramethylbenzyl)benzimidazolin-
2-ylidene](tricyclohexylphosphane)palladium (5d): The complex was
prepared as described for 3b by using 2d and PCy3. Yield: 0.88 g,
92.0%. 1H NMR (400 MHz, CDCl3): δ = 6.67 (m, 2 H, Ar-H),
6.22 (m, 2 H, Ar-H), 6.18 [s, 2 H, CH2C6H(CH3)4], 6.08 [s, 4 H,
CH2C6H(CH3)4], 2.56 (m, 3 H, PCy3-H), 2.35 [s, 12 H, o-C6H-
(CH3)4], 2.28 [s, 12 H, m-C6H(CH3)4], 2.03 (m, 6 H, PCy3-H), 1.83–
1.67 (m, 15 H, PCy3-H), 1.31 (m, 9 H, PCy3-H) ppm. 13C NMR
111.1 [Ar-C and PPh2 (2-py)-C and C6H(CH3 )4 -C], 52.0
[CH2C6H(CH3)4], 17.6 [m-C6H(CH3)5], 17.1 [o-C6H(CH3)4] ppm.
31P NMR (162.0 MHz, CDCl3): δ = 27.8 ppm. MS (MALDI): m/z
= 860 [M – Br]+. C46H48Br2N3PPd (940.1): calcd. C 58.77, H 5.15,
N 4.47; found C 58.71, H 5.18, N 4.46.
trans-Dibromido[N-(2-methoxyethyl)-NЈ-(pentamethylbenzyl)benz-
imidazolin-2-ylidene](tricyclohexylphosphane)palladium (5a): The
complex was prepared as described for 3a by using 2a and PCy3.
2
(100 MHz, CDCl3): δ = 180.0 (d, JC,P = 175.4 Hz, NCN), 136.0,
1
Yield: 0.83 g, 94.0%. H NMR (400 MHz, CDCl3): δ = 7.44 (d, J
135.6, 135.0, 133.4, 128.3, 122.9, 111.5 [Ar-C and C6H(CH3)4], 52.0
= 2.0 Hz, 1 H, Ar-H), 7.09 (t, J = 1.9 Hz, 1 H, Ar-H), 6.84 (t, J =
2.0 Hz, 1 H, Ar-H), 6.21 (d, J = 2.1 Hz, 1 H, Ar-H), 6.06 [s, 4 H,
CH2C6(CH3)5], 4.92 (t, J = 1.3 Hz, 2 H, NCH2CH2OCH3), 4.16 (t,
J = 1.3 Hz, 2 H, NCH2CH2OCH3), 3.37 (s, 3 H, NCH2CH2OCH3),
2.56 (m, 3 H, PCy3-H), 2.32 [s, 6 H, o-C6(CH3)5], 2.26 [s, 6 H, m-
C6(CH3)5], 2.06 [s, 3 H, p-C6(CH3)5], 1.81–1.68 (m, 14 H, PCy3-H),
1.30–1.20 (m, 16 H, PCy3-H) ppm. 13C NMR (100 MHz,CDCl3):
1
[CH2C6H(CH3)4], 32.3 (d, JP,C = 19.0 Hz, PCy3-C), 30.2 (PCy3-
C), 27.9 (d, 2JP,C = 9.7 Hz, PCy3-C), 26.7, 26.5, 26.1 (PCy3-C), 18.5
[m-C6H(CH3)4], 17.1 [o-C6H(CH3)4] ppm. 31P NMR (162.0 MHz,
CDCl3): δ = 22.3 ppm. MS (MALDI): m/z = 877 [M – Br]+.
C49H71Br2N2PPd (957.25): calcd. C 58.97, H 7.05, N 2.93; found
C 58.96, H 7.03, N 3.00.
2
δ = 179.4 (d, JC,P = 174.7 Hz, NCN), 136.2, 136.1, 136.0, 135.2,
Bromido[N-(2-methoxyethyl)-NЈ-(pentamethylbenzyl)benzimid-
133.3, 128.4, 122.8, 122.4, 111.8, 111.0 [Ar-C and C6(CH3)5], 71.4
azolin-2-ylidene][1,2-bis(diphenylphosphanyl)ethane]palladium (6a):
(NCH2CH2OCH3), 59.3 (NCH2CH2OCH3), 52.0 [CH2C6(CH3)5], The complex was prepared as described for 3a by using 2a and
48.1 (NCH2CH2OCH3), 32.6 (d, JP,C = 19.0 Hz, PCy3-C), 30.4 PPh2CH2CH2PPh2. Yield: 0.85 g, 85.0%. 1H NMR (400 MHz,
1
(PCy3-C), 27.9 (d, 2JP,C = 10.7 Hz, PCy3-C), 26.9, 26.5, 25.8 (PCy3- CDCl3): δ = 8.13 (m, 2 H, Ph-H), 8.08 (m, 4 H, Ph-H), 7.91 (m, 2
C), 17.9 [p-C6(CH3)5], 17.5 [m-C6(CH3)5], 17.1 [o-C6(CH3)5] ppm. H, Ph-H), 7.66 (m, 2 H, Ar-H), 7.60–7.21 (m, 13 H, Ar-H, Ph-H),
31P NMR (162.0 MHz, CDCl3): δ = 23.4 ppm. (MALDI): m/z =
803 [M – Br]+. C40H61Br2N2OPPd (883.12): calcd. C 54.40, H 6.96,
N 3.17; found C 54.51, H 6.83, N 3.19.
6.90 (t, J = 1.2 Hz, 1 H, Ar-H), 5.93 [s, 1 H, CHHC6(CH3)5], 5.00
[s, 1 H, CHHC6(CH3)5], 4.88 (t, J = 1.2 Hz, 2 H, NCH2CH2OCH3),
4.23 (t, J = 1.2 Hz, 2 H, NCH2CH2OCH3), 3.86–3.72 (m, 2 H,
Eur. J. Inorg. Chem. 2009, 285–294
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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