ACCEPTED MANUSCRIPT
of NaNO2 were added with subsequent addition of 2 mL 33 % HCl in portions of 0.2 mL for 1 h,
under vigorous stirring. During the reaction, the temperature of the mixture must not exceed +5 °C.
The obtained diazonium salt was used for the next stage (see below).
Azocoupling: 10 mmol of NaOH were added to a solution of 10 mmol of acetoacetanilide in 50 mL
water-ethanol (1/5, v/v). The solution was cooled in an ice bath, and a suspension of 2-
carboxybenzenediazonium chloride (prepared according to the procedure described above) was
added in two equal portions under rigorous stirring for 1 h. Then the system was acidified by
addition of concentrated HCl (until pH 5). The formed yellow precipitate of (Z)-2-(2-(1,3-dioxo-1-
(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid (H3L1) was filtered off, recrystallized from
methanol and dried in air.
H3L1: Yield 84 % (based on acetoacetanilide), yellow powder, soluble in water, DMSO, ethanol and
dimethylformamide and insoluble in non-polar solvents. Anal. Calcd. for C17H15N3O4 (M =
325.32): C, 62.76; H, 4.65; N, 12.92. Found: C, 62.67; H, 4.74; N, 12.98 %. IR (KBr): 3436 (br.)
ν(H2O), 3240 ν(NH), 1696 and 1663 ν(C=O), 1599 ν(C=N) cm−1. MS (ESI) (positive ion mode):
m/z: 326.11 [Mr+H]+. 1H NMR (DMSO-d6): δ 2.54 (s, 3H, CH3), 7.15−8.00 (9H, Ar−H), 11.08 (s,
1H, NH), 14.84 (s, 1H, NH). 13C{1H} (DMSO-d6): δ 26.56 (CH3), 115.67 (Ar−H), 116.47(Ar−H),
120.66 (2Ar−H), 124.06 (Ar−H), 124.96 (Ar−H), 129.54 (2Ar−H), 131.06 (Ar−H), 131.86
(Ar−COOH), 135.00 (C=N), 137.85 (Ar−CNH), 143.96 (Ar−NH−N), 161.07 (−COOH), 168.41
and 199.26 (C=O).
2.3. Synthesis of [Cu(HL1)(H2O)(CH3OH)] (1)
0.1 mmol (32 mg) of H3L1 were dissolved in 20 mL of methanol, then 2 drops of Et3N and 0.1
mmol (23 mg) of Cu(NO3)2ꢀ2.5H2O were added. The mixture was stirred for 5 min and left for slow
evaporation. Greenish crystals of the product started to form after ca. 2 d at room temperature; they
were filtered off and dried in air.
1: Yield, 56 % (based on Cu). Calcd. for C18H19CuN3O6 (Mr = 436.06): C 49.48, H 4.38, N 9.62;
found C 49.31, H 4.26, N 9.52. MS (ESI, positive ion mode), m/z: 387.0 [Mr−CH3OH−H2O+H]+.
IR (KBr): 3461 (s, br) ν(OH), 3007 ν(NH), 1674 (s) ν(C=O), 1591 (s) ν(C=N) cm–1.
2.4. Synthesis of [Cu(HL2)(H2O)(CH3OH)] (2)
0.1 mmol (37 mg) of NaH2L2 were dissolved in 25 mL of methanol, then 0.1 mmol (23 mg) of
Cu(NO3)2ꢀ2.5H2O was added and the system was stirred for 10 min. After ca. 2 d at room
temperature, greenish crystals precipitated, which were then filtered off and dried in air.
2: Yield, 53 % (based on Cu). Calcd. for C17H19CuN3O7S (Mr = 472.96): C 43.17, H 4.05, N 8.88;
found C 43.24, H 3.98, N 8.77. MS (ESI, positive ion mode), m/z: 423.9 [Mr−CH3OH−H2O+H]+.
IR (KBr): 3415 (s, br) ν(OH), 3280 ν(NH), 1627 (s) ν(C=O), 1599 ν(C=N) cm–1.
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