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hydrazine monohydrate was added. The reaction mixture was refluxed in 100 °C for 24 h. The
reaction was monitored by TLC. The reaction mixture was slowly allowed to cool to ambient
temperature. Yellow crystalline product was precipitated, separated by filtration, washed with cold
-1
ethanol/water and dried in vacuo. Yield (53%, 1.178 g). IR (KBr), ν (cm ): ν(Ν-Η)secondary: 3500
(broad (br)); ν(Ν-Η)primary: 3320 (m), 3200 (m); ν(C-N), 1637 (m); δ(Ν-Η)primary: 1616 (m); w(Ν-Η):
1
7
7
63 (m). H NMR (500 MHz, DMSO-d ), δ (ppm): 9.62 (brs, 1H), 8.47 (brs, 1H), 8.16 (brs, 1H),
6
.71 (brs, 1H), 7.65 (brs, 1H), 7.45 (brs, 1H), 4.74 (brs, 2H).
rd
2
.2.3 Synthesis of (E)-4-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazoline, L (3 step).
In an ethanolic solution of quinazolin-4-yl-hydrazine (II) (350 mg, 2.17 mmol), 2-
pyridinecarboxaldehyde (206 μL, 2.17 mmol) was added slowly at 90 °C with continuous stirring in
the presence of a few drops of p-toluenesulfonic acid as catalyst for 3 h. The reaction was
monitored by TLC. The reaction mixture was slowly allowed to cool to ambient temperature.
Yellow crystalline product of L was separated by filtration, washed with cold ethanol. Drying in
vacuo afforded 320 mg (yield 61 %) of a yellow solid of L which was used without further
1
purification. The compound L is soluble in MeOH and DMSO. H NMR (500 MHz, DMSO-d ), δ
6
(ppm): 11.83 (s, 1H, NH), 8.64 (dd, J = 4.8, 0.7 Hz, 1H, H-6’), 8.45 (s, 1H, H-2), 8.44 (d, J = 8.0
Hz, 1H, H-3’), 8.26 (d, J = 7.8 Hz, 1H, H-5), 7.92 (s, 1H, C(H)=N), 7.90 (dt, J = 7.7, 1.2 Hz, 1H,
H-4’), 7.70 (t, J = 7.2 Hz, 1H, H-7), 7.54 (d, J = 8.1 Hz, 1H, H-8), 7.46 (t, J = 7.7 Hz, 1H, H-6),
+
7
.43 (dt, J = 6.3, 1.1 Hz, 1H, H-5’). HRMS (ESI) (m/z): calc. for C H N [M+H] 250.1087;
1
4
11
5
-1
found 250.1087. IR (KBr), ν(cm ): ν(Ν-Η)secondary: 3164(m); ν(C=N): 1623(vs), 1606 (s); w(Ν-Η):
-1
-1
7
69 (m). UV-vis in DMSO, λ (nm) (ε, M cm ): 433 (shoulder (sh)) (1000), 365 (7350), 294
(4500).
2
2
.3 Synthesis of the complexes
.3.1 Synthesis of [Zn(L) ](NO ) ·MeOH, 1·MeOH
2
3 2
The complex was synthesized via the addition of a methanolic solution (3 mL) of L (31 mg,
.12 mmol) to a methanolic solution of Zn(NO ) ·4H O (16 mg, 0.06 mmol). After stirring for 15
0
3
2
2
min, 2 mL of H O was added and the mixture was left for slow evaporation. Colorless single-
2
crystals of [Zn(L) ](NO ) ·MeOH (1·MeOH) suitable for X-ray structure determination were
2
3 2
deposited (17 mg, ~40 %) after one month. The complex is soluble in DMSO (ΛM = 105
2
-1
S·cm ·mol , 1 mM in DMSO). Anal. calc. for C H N O Zn (MW = 719.98) C, 48.37; H, 3.64;
2
9
26 12
7
-1
N, 23.35; found: C, 48.52; H, 3.45; N, 23.16 %. IR (KBr), ν(cm ): ν(Ν-Η), 3451 (br); ν(C-H): 2924
(
m); ν(C=N): 1635 (s), 1614 (vs); ν (ΝO ): 1383 (vs); ν (ΝΟ ), 823 (m); w(N-H): 751(m); ρ(C-
3
3
2
3
-1
-1
H)out-of-plane,py: 691 (m). UV-vis in DMSO, λ (nm) (ε, M cm ): 454 (2900), 430 (sh) (2500), 402(sh)
7