Organic & Biomolecular Chemistry
Paper
(KBr, νmax/cm−1): 3055, 3024, 2957, 2923, 2851, 2216, 2157, 687, 666, 487 cm−1
.
1H NMR (400 MHz, CDCl3, δ/ppm): 7.28
1956, 1642, 1579, 1529, 1456, 1390, 1309, 1247, 1161, 1096, (d, 3J = 8.4 Hz, 2 H), 7.35–7.40 (m, 2 H), 7.58–7.62 (m, 2 H),
1022, 991, 872, 841, 751, 698, 667, 524, 495. 1H NMR 7.71 (d, 3J = 8.4 Hz, 2 H), 7.98 (dd, 3J = 8.4 Hz, 4J = 2.0 Hz, 1 H),
3
3
(400 MHz, CDCl3, δ/ppm): 0.28 (s, 9 H), 7.31–7.33 (m, 2 H), 8.40 (d, J = 5.2 Hz, 1 H), 8.51 (d, J = 8.4 Hz, 1 H), 8.86 (bs,
3
4
7.52–7.57 (m, 2 H), 7.99 (dd, J = 8.4 Hz, J = 2.4 Hz, 1 H), 8.39 1 H), 8.89 (d, 3J = 5.2 Hz, 1 H), 9.31 (bs, 1 H). 13C NMR
3
3
(d, J = 4.8 Hz, 1 H), 8.51 (d, J = 8.4 Hz, 1 H), 8.86–8.89 (m, (100 MHz, CDCl3, δ/ppm): 89.3, 90.0, 93.0, 93.3, 94.7, 117.6,
2 H), 9.30 (bs, 1 H). 13C NMR (100 MHz, CDCl3, δ /ppm): 0.0, 121.0, 122.2, 122.5, 124.8, 125.7, 128.4, 128.9, 132.0, 132.1,
89.7, 93.4, 99.2, 103.1, 117.7, 121.0, 122.3, 125.0, 125.9, 128.3, 133.0, 137.7, 139.5, 151.9, 152.6, 158.1, 158.8, 161.9. MS (ESI):
128.7, 131.9, 132.4, 139.6, 151.9, 152.4, 158.1, 158.7, calcd for [C25H14IN3 + H+]: m/z = 484.0, found m/z = 483.9.
162.0 ppm. MS (ESI): calcd for [C22H19N3Si + H+] m/z = 354.1, Elemental analysis (C25H14N3I): calcd C, 62.13; H, 2.92; N,
found m/z = 354.3. Elemental analysis (C22H19N3Si·0.5THF): 8.69, found C, 62.26; H, 2.89; N, 8.49.
calcd C, 74.00; H, 5.95; N, 10.79, found C, 74.37; H, 5.79;
N, 10.63.
Conclusions
4-(5-((2-Ethynylphenyl)ethynyl)pyridin-2-yl)pyrimidine (12)
In conclusion, we report on the synthesis and characterisation
of a two-state nanoswitch and its toggling using a redox-depen-
dent self-sorting protocol. From the two studied ferrocenyl
diimine ligands, only 2-ferrocenylphenanthroline (2a) showed
a fully reversible toggling process under oxidation/reduction
conditions in a quantitative manner as depicted in Scheme 1.
The oxidation-initiated switching of [Cu(1)(2a)]+/2+ furnishes
[Cu(1)]+ and 2a+ within 7 min, while the reverse process regen-
erated [Cu(1)(2a)]+ within 2 min by adding a reducing agent.
Compound 11 (230 mg, 651 μmol) was dissolved in 50 mL of
THF. 1 N KOH in methanol (30 mL) was added and the
mixture was stirred for 12 h at room temperature. The solvents
were evaporated and the solid residue was dissolved in dichloro-
methane (50 mL). Water was added and the organic layer was
separated. After extraction of the aqueous phase, the combined
organic layers were evaporated to dryness to afford the product
as a yellow solid. Yield: 170 mg (604 μmol, 93%). Mp: >300 °C.
IR (KBr, νmax/cm−1): 3055, 3024, 2955, 2922, 2802, 2215, 2153,
1569, 1526, 1453, 1386, 1306, 1245, 1156, 1092, 1020, 874, 843,
756, 697, 662, 641, 595. 1H NMR (400 MHz, CDCl3, δ/ppm):
3.41 (s, 1 H), 7.33–7.40 (m, 2 H), 7.56–7.60 (m, 2 H), 8.00 (dd,
3J = 8.4 Hz, 4J = 2.4 Hz, 1 H), 8.38 (dd, 3J = 5.6 Hz, 4J = 1.2 Hz, 1
Acknowledgements
3
5
We acknowledge generous funding by DFG (Schm 647/19-1)
and the Universität Siegen for financial support.
H), 8.51 (dd, J = 8.4 Hz, J = 0.8 Hz, 1 H), 8.87–8.89 (m, 2 H),
4
9.30 (d, J = 1.2 Hz, 1 H). 13C NMR (100 MHz, CDCl3, δ /ppm):
81.6, 81.9, 89.9, 93.0, 117.6, 121.0, 122.2, 124.9, 125.3, 128.7,
128.8, 131.9, 132.7, 139.6, 152.1, 152.5, 158.1, 158.7,
162.0 ppm. MS (ESI): calcd for [C19H11N3 + H+] m/z = 282.1,
Notes and references
found m/z
= 282.3. Elemental analysis (C19H11N3·0.166
CH2Cl2): calcd C, 77.91; H, 3.87; N, 14.22, found C, 78.14; H,
3.77; N, 13.90.
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4-(5-((2-((4-Iodophenyl)ethynyl)phenyl)ethynyl)pyridin-2-yl)-
pyrimidine (7)
Compound 12 (150 mg, 533 μmol) and 1,4-diiodobenzene
(1.76 g, 5.33 mmol) were dissolved in dry DMF (25 mL) and
dry triethylamine (25 mL) in a 100 mL three-neck round-
bottom flask equipped with a reflux condenser under a nitro-
gen atmosphere. After the solvent had been deaerated with
nitrogen for
1
h, tetrakis(triphenylphosphine)palladium
(50.0 mg, 43.2 μmol) was added and heated at 80 °C for 2 days.
The solvents were removed under reduced pressure and the
residue was dissolved in dichloromethane (50 mL). The
organic layer was washed with water, dried over sodium
sulfate, and evaporated to dryness. The solid residue was puri-
fied (Rf = 0.4 in 10% EtOAc in DCM) using column chromato-
graphy (2% ethyl acetate in dichloromethane) to furnish the
pure product 7 as a yellow solid. Yield: 150 mg (310 μmol,
58%). Mp: Decomposition >204 °C. IR (KBr, νmax/cm−1): 3042,
2360, 2337, 2217, 1944, 1896, 1734, 1637, 1578, 1528, 1488,
1456, 1388, 1313, 1226, 1121, 1056, 1006, 949, 836, 812, 781,
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