Synthetic Route for the Preparation of Nonsymmetric Metallo-salphen Complexes
FULL PAPER
Monoimine 10:
22.73 mmol)
A
and
mixture of 3,4-diaminopyridine (2.48 g,
3,5-di(tert-butyl)salicylaldehyde
(1.84 g, uct as a yellow-orange solid. Yield: 0.89 g (81%). 1H NMR
(300 MHz, [D6]acetone/5% [D5]pyridine): δ = 1.30 [s, H,
ish suspension was obtained, which was filtered to furnish the prod-
7.85 mmol) in MeOH (40 mL) was stirred at room temp. for 24 h.
Then the mixture was filtered and the product collected by fil-
tration and dried. Concentration of the mother liquor yielded a
second fraction of a yellow solid. Total yield: 1.73 g (68%). 1H
NMR (300 MHz, [D6]acetone): δ = 1.34 [s, 9 H, C(CH3)3], 1.46 [s, 6.3, JH,H = 2.1 Hz, 2 H, ArH), 7.44 (d, JH,H = 2.7 Hz, 1 H, pyr-
9 H, C(CH3)3], 5.60 (br. s, 2 H, NH2), 6.75 (d, JH,H = 5.7 Hz, 1
9
3
C(CH3)3], 1.53 [s, 9 H, C(CH3)3], 6.45 (t, JH,H = 7.8 Hz, 1 H,
3
ArH), 6.82 (d, 3JH,H = 8.4 Hz, 1 H, ArH), 6.94 (d, JH,H = 7.8 Hz,
4
3
1 H, Ar-H), 7.23 (d, JH,H = 2.7 Hz, 1 H, ArH), 7.36 (t, JH,H
=
4
4
3
4
3
H), 7.46 (d, JH,H = 2.7 Hz, 1 H, ArH), 7.84 (t, JH,H = 8.7 Hz, 1
H, pyr-H), 9.00 [s, 1 H, C(H)=N], 9.05 [s, 1 H, C(H)=N] ppm. The
OH proton was in exchange with residual water in the solvent.
13C{1H} NMR (75 MHz, [D6]DMSO/5% [D5]pyridine): δ = 29.40,
3
H, pyr-H), 7.51 (pseudo s, 2 H, ArH), 8.01 (d, JH,H = 5.4 Hz, 1
H, pyr-H), 8.11 (s, 1 H, pyr-H), 8.86 [s, 1 H, C(H)=N], 13.30 (s, 1
H, OH) ppm. 13C{1H} NMR (75 MHz, [D6]acetone): δ = 29.84,
31.81, 34.84, 35.68, 110.12, 119.83, 128.50, 128.71, 132.99, 137.15, 31.29, 33.53, 35.18, 113.16, 113.47, 116.75, 117.28, 118.21, 125.27,
140.24, 141.60, 148.76, 148.94, 158.73, 165.85 ppm. UV/Vis (tolu-
ene, c = 1.753 mg/50 mL): λmax (ε) = 365 nm (9400 mol–1 dm3 cm–1).
MS (LC-MS, direct inlet, CH3CN, APCI): m/z = 322 [M+ + H].
C20H27N3O (325.22): calcd. C 73.65, H 8.42, N 12.78; found C
73.81, H 8.36, N 12.91.
126.81, 127.73, 128.80, 129.74, 133.61, 139.19, 140.16, 140.71,
148.88, 159.24, 163.13, 164.11, 170.53 ppm. UV/Vis (DMF, c =
1.746 mg/50 mL): λmax (ε) = 414 nm (15500 mol–1 dm3 cm–1). MS
(LC-MS, direct inlet, CH3CN, APCI): m/z = 507 [M+ + H], 548
[M+ + H + CH3CN], 1017 [2M+ + H]. C28H30N2O3Zn (506.15):
calcd. C 66.21, H 5.95, N 5.52; found C 66.07, H 6.10, N 5.38.
ZnII-salphen Complex 11: A mixture of monoimine 1 (0.44 g,
1.36 mmol),
5-bromo-3-(tert-butyl)salicylaldehyde[20]
(0.35 g,
ZnII-salphen Complex 14: A yellow suspension of 2,4-dihydroxy-
1.36 mmol), Zn(OAc)2·2H2O (0.33 g, 1.50 mmol) and neat NEt3 benzaldehyde (0.22 g, 1.59 mmol), monoimine
1
(0.47 g,
(2 mL) in MeOH (40 mL) was stirred at room temp. for 68 h. Then
two volumes of H2O were added and the product collected by fil-
tration, dried and triturated with pentane to furnish an orange-
yellow solid. Yield: 0.50 g (60%). 1H NMR (300 MHz, [D6]ace-
1.45 mmol) and Zn(OAc)2·2H2O (0.35 g, 1.59 mmol) in MeOH
(40 mL) was stirred at room temp. for 18 h. Hereafter, water was
added to precipitate the product, which was washed with pentane
and isolated by filtration. Drying in vacuo afforded a yellow solid.
tone): δ = 1.31 [s, 9 H, C(CH3)3], 1.51 [s, 9 H, C(CH3)3], 1.53 [s, 9 Yield: 0.51 g (69%). 1H NMR (300 MHz, [D6]acetone/5% [D5]pyri-
4
4
H, C(CH3)3], 7.26 (d, JH,H = 2.7 Hz, 1 H, ArH), 7.29 (d, JH,H
=
=
dine): δ = 1.30 [s, 9 H, C(CH3)3], 1.49 [s, 9 H, C(CH3)3], 6.13 (d,
4
4
4
2.7 Hz, 1 H, ArH), 7.37–7.40 (m, 2 H, ArH), 7.45 (d, JH,H
3JH,H = 8.7, JH,H = 8.7 Hz, 1 H, ArH), 6.26 (d, JH,H = 2.4 Hz, 1
4
2.7 Hz, 1 H, ArH), 7.93–7.96 (m, 2 H, ArH), 9.05 [s, 1 H, C(H)=N], H, ArH), 7.21–7.30 (m, 4 H, Ar-H), 7.42 (d, JH,H = 2.7 Hz, 1 H,
9.12 [s, 1 H, C(H)=N] ppm. 13C{1H} NMR (75 MHz, [D6]acetone): ArH), 7.72–7.76 (m, 2 H, ArH), 8.85 [s, 1 H, C(H)=N], 8.96 [s, 1
δ = 30.00, 30.15, 34.40, 36.23, 103.74, 116.53, 116.70, 119.25,
121.89, 127.38, 128.11, 129.94, 130.35, 133.67, 134.79, 136.09,
140.23, 141.04, 142.25, 145.86, 162.13, 163.65, 171.92, 172.08 ppm.
H, C(H)=N] ppm. The OH proton was in exchange with residual
water in the solvent which appeared as a broad signal at δ =
3.01 ppm. 13C{1H} NMR (75 MHz, [D6]DMSO/10% [D5]pyri-
dine): δ = 29.63, 30.69, 31.41, 33.61, 35.29, 105.12, 107.06, 113.89,
UV/Vis (toluene,
c = 0.814 mg/50 mL): λmax (ε) = 427 nm
(17000 mol–1 dm3 cm–1). MS (LC-MS, direct inlet, CH3CN, APCI): 115.92, 116.39, 118.37, 123.48, 123.80, 124.13, 126.25, 126.80,
m/z = 627 [M+ + H], 668 [M+ + H + CH3CN], 707 [M+ + H +
2CH3CN]. C32H37BrN2O2Zn (624.13): calcd. C 61.30, H 5.95, N
4.47; found C 61.39, H 6.05, N 4.55.
128.49, 129.66, 133.34, 136.58, 138.20, 139.74, 140.01, 140.76,
148.44, 148.81, 149.15, 161.15, 164.11, 170.50, 174.77 ppm. UV/Vis
(toluene,
c
=
1.888 mg/50 mL): λmax (ε)
=
398 nm
(15800 mol–1 dm3 cm–1). MS (LC-MS, direct inlet, CH3CN, APCI):
m/z = 505 [M+ + H], 546 [M+ + H + CH3CN], 1017 [2M+ + H].
C28H30N2O3Zn·3.5H2O (506.15 for complex without H2O): calcd.
C 58.90, H 6.53, N 4.91; found C 58.73, H 6.51, N 4.83.
ZnII-salphen Complex 12: A mixture of monoimine 2 (0.65 g,
1.81 mmol), 3-(tert-butyl)salicylaldehyde (0.33 g, 1.85 mmol),
Zn(OAc)2·2H2O (0.42 g, 1.91 mmol) and neat NEt3 (1 mL) in
MeOH (40 mL) was stirred at room temp. for 41 h. Then the prod-
uct was collected by filtration and dried to furnish a yellow solid.
Yield: 0.99 g (94%). 1H NMR (300 MHz, [D6]acetone): δ = 1.31 [s,
ZnII-salphen Complex 15: A mixture of monoimine 4 (0.42 g,
1.29 mmol), 3-(tert-butyl)salicylaldehyde (0.24 g, 1.35 mmol) and
9 H, C(CH3)3], 1.51 [s, 9 H, C(CH3)3], 1.53 [s, 9 H, C(CH3)3], 6.49 Zn(OAc)2·2H2O (0.33 g, 1.50 mmol) in MeOH (40 mL) was stirred
4
(t, 3JH,H = 7.2 Hz, 1 H, ArH), 7.24 (d, JH,H = 2.7 Hz, 1 H, ArH),
at room temp. for 3 d. Then the product was collected by filtration
4
7.29–7.33 (m, 2 H, ArH), 7.36 (d, JH,H = 2.1 Hz, 1 H, ArH), 7.45
to furnish an orange-red solid (178.6 mg, 25%). 1H NMR
(d, 4JH,H = 2.7 Hz, 1 H, ArH), 7.93 (d, 3JH,H = 5.7 Hz, 1 H, ArH), (300 MHz, [D6]acetone): δ = 1.33 [s, 9 H, C(CH3)3], 1.53 [s, 9 H,
3
7.95 (s, 1 H, ArH), 9.10 [s, 1 H, C(H)=N], 9.11 [s, 1 H, C(H)=N] C(CH3)3], 1.58 [s, 9 H, C(CH3)3], 6.53 (t, JH,H = 7.2 Hz, 1 H,
ppm. 13C{1H} NMR (75 MHz, [D2]dichloromethane/5% [D5]pyri-
dine): δ = 29.80, 29.90, 31.65, 34.30, 35.87, 36.11, 113.41, 116.50,
117.35, 118.56, 119.80, 127.02, 129.72, 130.42, 131.90, 132.47,
134.80, 135.04, 139.57, 141.58, 142.64, 143.42, 163.24, 163.38,
172.02, 173.90 ppm. UV/Vis (toluene, c = 0.728 mg/50 mL): λmax
ArH), 7.31–7.37 (m, 3 H, ArH), 7.52 (d, 4JH,H = 2.7 Hz, 1 H, ArH),
3
3
7.75 (d, JH,H = 6.0 Hz, 1 H, pyr-Hmeta), 8.46 (d, JH,H = 5.7 Hz,
1 H, pyr-Hortho), 8.61 (s, 1 H, pyr-Hortho), 9.16 [s, 1 H, C(H)=N],
9.28 [s, 1 H, C(H)=N] ppm. 13C{1H} NMR (75 MHz, [D2]dichloro-
methane/30% [D5]pyridine): δ = 29.72, 29.85, 31.52, 34.12, 35.74,
(ε) = 429 nm (20700 mol–1 dm3 cm–1). MS (LC-MS, direct inlet, 36.01, 109.84, 113.67, 118.69, 119.66, 129.74, 130.40, 132.52,
CH3CN, APCI): m/z = 583 [M+ + H], 622 [M+ + H + CH3CN], 661 135.06, 139.10, 142.55, 143.52, 146.19, 147.69, 163.71, 164.89,
[M+ + H + 2CH3CN]. C32H37ClN2O2Zn·H2O (580.18 for complex
without H2O): calcd. C 64.00, H 6.55, N 4.66; found C 63.85, H
6.78, N 4.51.
172.08, 174.90 ppm. UV/Vis (DMF, c = 1.294 mg/50 mL): λmax (ε)
=
426 nm (20900 mol–1 dm3 cm–1). MS (LC-MS, direct inlet,
CH3CN, APCI): m/z = 547 [M+ + H], 588 [M+ + H + CH3CN],
626 [M+ + H + 2CH3CN]. C31H37N3O2Zn (547.22): calcd. C 67.82,
H 6.79, N 7.65; found C 68.64, H 6.66, N 7.72.
ZnII-salphen Complex 13: A green suspension of 2,3-dihydroxy-
benzaldehyde (0.30 g, 2.17 mmol), monoimine
2.19 mmol) and Zn(OAc)2·2H2O (0.48 g, 2.19 mmol) in MeOH
1
(0.71 g,
ZnII-salphen Complex 16: A mixture of 2,3-diaminonaphthalene
(40 mL) was stirred at room temp. for 24 h. In due course, a yellow-
(0.42 g,
2.65 mmol),
3-(tert-butyl)salicylaldehyde
(1.10 g,
Eur. J. Inorg. Chem. 2005, 4626–4634
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4631