M. Blomenkemper et al. / Inorganica Chimica Acta 366 (2011) 76–80
79
3.66 (s, 2H, SCH2Ph), 2.70 (t, 2H, SCH2), 2.45 (t, 2H, NCH2), 1.64
(quint, 2H, CH2CH2CH2), 1.13 (NH2). 13C{1H} NMR (50.3 MHz,
CDCl3): d 138.0 (Ar-Cipso), 129.7, 128.9, 127.4 (Ar-C), 43.7 (SCH2Ph),
36.4 (SCH2), 36.1 (NCH2), 29.5 CH2CH2CH2.
ions, m/z): 496 [M+H]+. Anal. Calc. for C29H37NS3 (495.81): C, 70.25;
H, 7.52; N, 2.83. Found: C, 70.11; H, 7.68; N, 2.64%.
4.4.4. Synthesis of N,N,N-tris-(3-benzylmercaptopropyl)amine (6)
Ligand 6 was synthesized from 3-benzylmercaptopropylamine
1b (5.44 g, 30.0 mmol) and 3-benzylmercaptopropylbromide 2b
(14.71 g, 60.0 mmol). Yield: 13.32 g (26.1 mmol, 87%) of a colorless
oil. 1H NMR (300.1 MHz, CDCl3): d 7.10 (m, 15H, Ar-C), 3.72 (s, 6H,
SCH2Ph), 2.55–2.34 (m, 12H, NCH2 and SCH2), 1.74 (quint, 6H,
CH2CH2CH2). 13C{H} NMR (50.3 Hz, CDCl3): d 139.0 (Ar-Cipso),
129.9, 126.6 (Ar-C), 51.1 (NCH2), 38.7 (SCH2Ph), 33.2 (SCH2), 30.4
(CH2CH2CH2). MALDI-MS (TOF, positive ions, m/z): 510 [M+H]+.
Anal. Calc. for C30H39NS3 (509.84): C, 70.67; H, 7.71; N, 2.75. Found:
C, 70.52; H, 7.62; N 2.68%.
4.3.3. Synthesis of N,N-bis(2-benzylmercaptoethyl)amine (1c)
The product was synthesized from N,N-bis(2-chloropro-
pyl)amine hydrochloride (17.85 g, 100 mmol). Yield: 26.95 g,
(84.9 mmol, 85%) of a colorless oil (bp 180 °C at 0.07 mbar). 1H
NMR (200.1 MHz, CDCl3): d 7.28 (m, 10H, Ar-H) 3.66 (s, 4H,
SCH2Ph), 2.70 (t, 4H, SCH2), 2.45 (t, 4H, NCH2), 1.13 (s, 1H, NH).
13C{1H} NMR (50.3 MHz, CDCl3): d 138.0 (Ar-Cipso), 129.7, 128.9,
127.4 (Ar-C), 43.7 (SCH2Ph), 36.4 (SCH2), 36.1 (NCH2) ppm.
MALDI-MS (TOF, positive ions, m/z): 318 [M+H]+. Anal. Calc. for
C18H23NS2 (317.52): C, 68.09; H, 7.30; N, 4.41. Found: C, 67.01;
H, 7.32; N 4.46%.
4.5. General procedure for the synthesis of the copper(I) complexes
7–9
4.4. General procedure for the synthesis of ligands 3–6
Copper(I)tetrakisacetonitrile
tetrafluoroborate
(79 mg,
A sample of the
in 150 mL of acetonitrile and the appropriate amount of
-benzylmercaptoalkylbromide and potassium carbonate (40 g,
240 mmol for coupling to the primary amines 1a and 1b, 20 g,
120 mmol for coupling to the secondary amine 1c) were added.
The reaction mixture was heated under reflux for 16 h and after
removal of the solvent in vacuo the ligands were purified by column
chromatography (aluminum oxide, THF/n-hexane 1:1).
x
-benzylmercaptoalkylamine was dissolved
0.25 mmol) was dissolved in 15 mL of acetone. To this solution
was added a solution of one of the tripidal ligands 4–6 (0.25 mmol)
in 10 mL of acetone. The reaction mixture was stirred for 30 min at
ambient temperature. Subsequently, diethyl ether (50 mL) was
added dropwise and the precipitated colorless solid was collected
by filtration and dried in vacuo.
x
4.5.1. Synthesis of [Cu(4)](BF4) (7)
The complex was prepared from ligand 4 (120 mg, 0.25 mmol).
Crystals suitable for an X-ray diffraction study were obtained by
slow diffusion of diethyl ether into a solution of the complex in
acetone. Yield: 147 mg (0.23 mmol, 92%) of a colorless solid. 1H
4.4.1. Synthesis of N,N,N-tris(2-benzylmercaptoethyl)amine (3)
The published procedure for the preparation of 3 [17] was al-
tered to avoid the highly toxic and carcinogenic starting material
N,N,N-tris(2-chloroethyl)amine (‘‘N-Lost”). Ligand 3 was synthe-
sized from N,N-bis(2-benzylmercaptoethyl)amine 1c (4.92 g,
15.5 mmol) and 2-benzylmercaptoethylbromide 2a (3.58 g,
15.5 mmol). Yield: 6.92 g (14.8 mmol, 95%) of a colorless oil. 1H
NMR (300.1 MHz, CDCl3): d 7.10 (m, 15H, Ar-H), 3.72 (s, 6H,
SCH2Ph), 2.55 (t, 6H, NCH2), 2.34 (t, 6H, SCH2). 13C{H} NMR (CDCl3,
50.3 MHz): d 139.0 (Ar-Cipso), 129.9, 128.8, 127.5 (Ar-C), 51.1
(NCH2), 39.2 (SCH2Ph), 38.7 (SCH2). MALDI-MS (TOF, positive ions,
m/z): 468 [M+H]+. Anal. Calc. for C27H33NS3 (467.76): C, 69.33; H,
7.11; N, 2.99. Found: C, 69.20; H, 7.33; N 3.22%.
NMR (300.1 MHz, [D6]acetone):
d 7.48–7.32 (m, 15H, Ar-H),
4.16–4.08 (m, 6H, SCH2Ph), 3.14–2.80 (m, 12H, NCH2 and SCH2),
2.06(quint, 2H, CH2CH2CH2). 13C{1H} NMR (50.3 MHz, [D6]acetone:
d 136.8 (Ar-Cipso), 129.5, 126.8 (Ar-C) 59.7 (NCH2CH2CH2SCH2Ph),
52.4 (NCH2CH2SCH2Ph), 38.8 (NCH2CH2S), 38.2 (NCH2CH2CH2S),
33.5 (NCH2CH2S), 33.4 (NCH2CH2CH2S), 24.3 (NCH2CH2CH2S). MAL-
DI-MS (TOF, positive ions, m/z): 632 [M+H]+. Anal. Calc. for
C28H35NBCuF4S3 (632.15): C, 53.20; H, 5.58; N, 2.22. Found: C,
53.72; H, 5.26; N, 2.48%.
4.5.2. Synthesis of [Cu(5)](BF4) (8)
4.4.2. Synthesis of N,N-bis(2-benzylmercaptoethyl)-N-(3-
benzylmercaptopropyl)amine (4)
The complex was prepared from ligand 5 (124 mg, 0.25 mmol).
Yield: 140 mg (0.22 mmol, 88%) of a colorless solid. 1H NMR
(300.1 MHz, [D6]acetone): d 7.51–7.32 (m, 15H, Ar-H), 4.13–4.00
(m, 6H, SCH2Ph), 3.09–2.82 (m, 12H, NCH2 and SCH2), 2.04 (quint,
4H, CH2CH2CH2). 13C{1H} NMR (50.3 MHz, [D6]: d 136.2 (Ar-Cipso),
130.1, 126.4 (Ar-C), 59.5 (NCH2CH2CH2SCH2Ph), 54.7 (NCH2CH2-
SCH2Ph), 40.4 (NCH2CH2S), 39.4 (NCH2CH2CH2S), 33.3 (NCH2CH2S),
32.4 (NCH2CH2CH2S), 23.7 (NCH2CH2CH2S). MALDI-MS (TOF,
positive ions, m/z): 646 [M+H]+. Anal. Calc. for C29H37NCuBF4S3
(646.17): C, 53.90; H, 5.77; N 2.17. Found: C, 53.98; H, 5.22; N,
2.28%.
Ligand 4 was synthesized from N,N-bis(2-benzylmercaptoeth-
yl)amine 1c (6.00 g, 18.9 mmol) and 3-benzylmercaptopropylbro-
mide 2b (4.63 g, 18.9 mmol). Yield: 8.09 g (16.8 mmol, 89%) of a
colorless oil. 1H NMR (300.1 MHz, CHCl3): d 7.10 (m, 15H, Ar-C),
3.72 (s, 6H, SCH2Ph), 2.55–2.34 (m, 12H, NCH2 and SCH2), 1.74
(quint, 2H, CH2CH2CH2). 13C{H} NMR (50.3 MHz, CDCl3): d 139.0
(Ar-Cipso), 129.9, 126.6 (Ar-C), 55.5 (NCH2CH2S), 51.1 (NCH2CH2-
CH2S), 38.7 (SCH2Ph), 33.2 (SCH2), 30.4 (CH2CH2CH2). MALDI-MS
(TOF, positive ions, m/z): 482 [M+H]+. Anal. Calc. for C28H35NS3
(481.79): C, 69.80; H, 7.32; N, 2.91. Found: C, 69.92; H, 7.22; N
2.78%.
4.5.3. Synthesis of [Cu(6)](BF4) (9)
The complex was prepared from ligand 6 (127 mg, 0.25 mmol).
Crystals suitable for an X-ray diffraction study were obtained by
slow diffusion of diethyl ether into a solution of the complex in
acetone. Yield: 148 mg (0.22 mmol, 88%) of a colorless solid. 1H
4.4.3. Synthesis of N-(2-benzylmercaptoethyl)-N,N-bis-(3-benzylmer-
captopropyl)amine (5)
Ligand 5 was synthesized from 2-benzylmercaptoethylamine
1a (5.02 g, 30.0 mmol) and 3-benzylmercaptopropylbromide 2b
(14.71 g, 60.0 mmol). Yield: 13.89 g (28.0 mmol, 93%) of a colorless
oil. 1H NMR (300.1 MHz, CDCl3): d 7.10 (m, 15H, Ar-C), 3.72 (s, 6H,
SCH2Ph), 2.55–2.34 (m, 12H, NCH2 and SCH2), 1.74 (quint, 4H,
CH2CH2CH2). 13C{H} NMR (50.3 MHz, CDCl3): d 139.0 (Ar-Cipso),
129.9, 126.6 (Ar-C), 55.5 (NCH2CH2S), 51.1 (NCH2CH2CH2S), 38.7
(SCH2Ph), 33.2 (SCH2), 30.4 (CH2CH2CH2). MALDI-MS (TOF, positive
NMR (300.1 MHz, [D6]acetone):
d 7.51–7.32 (m, 15H, Ar-H),
4.13–4.00 (m, 6H, SCH2Ph), 3.09–2.82 (m, 12H, NCH2 and SCH2),
2.04 (quint, 6H, CH2CH2CH2). 13C{1H} NMR (50.3 MHz, [D6]ace-
tone): d 136.8 (Ar-Cipso), 129.5, 128.2 (Ar-C), 61.0 (SCH2Ph), 39.6
(NCH2), 33.0 (SCH2), 23.1 (CH2CH2CH2). MALDI-MS (TOF, positive
ions, m/z): 660 [M+H]+. Anal. Calc. for C30H39NCuBF4S3 (660.20):
C, 54.88; H, 5.95; N, 2.12. Found: C, 54.92; H, 5.42; N, 2.18%.