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Updated: May 14, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Syntheses, structure diversity and properties of complexes with 4-acyl pyrazolone salicylidene hydrazide derivatives
Li Zhang1, Guan-Cheng Xu, Yun Yang
1Key Laboratory of Material and Technology for Clean Energy, Ministry of Education, Autonomous Region, Institute of Applied Chemistry, Xinjiang University, Urumqi, 830046, Xinjiang, PR China.
Abstract:
Five new complexes [Zn(HL(1))(OAc)(CH(3)CH(2)OH)] (1), [Cd(2)(HL(1))(2)(OAc)(2)(CH(3)CH(2)OH)(2)] (2), [Cu(6)(L(1))(6)] (3) (H(2)L(1) = N-(1-phenyl-3-phenmethyl-4-phenylethylene-pyrazolone-5)-salicylidene hydrazide, OAc = acetate anion), {[Zn(L(2))(CH(3)OH)]·(CH(3)OH)}(n) (4) (H(2)L(2) = N-(1-phenyl-3-phenmethyl-4-ethylene-pyrazolone-5)-salicylidene hydrazine), [Cu(L(3))](n) (5) (H(2)L(3) = N-(1-phenyl-3-phenmethyl-4-benzylidene-pyrazolone-5)-salicylidene hydrazide) have been synthesized and characterized by chemical and spectroscopic techniques. Complexes 1-3 feature mononuclear, dinuclear and rare hexanuclear structures, respectively. The different molecular structures and different coordination modes of H(2)L(1) in complexes 1-3 indicate that the coordination geometry of the metal atoms have a remarkable impact on the structure of these complexes. Complexes 4 and 5 have 1D chain structures. Comparing complexes 4 and 1 or 5 and 3, it can be concluded that the substituents at the 4-position of the ligands have a significant effect on the structure of the resulting complexes. It is worth noting that N(2) atoms of the pyrazolyl ring play an important role in building the two-dimensional networks for 1 and 2 by hydrogen bonds, a novel hexanuclear unit for 3, and the 1D polymer chain for 4 and 5 by bridging bonds. Complexes 1, 2 and 4 show strong fluorescent behavior in the solid state. The magnetic property of complex 3 shows the presence of intramolecular antiferromagnetic exchange (J = -8.63 cm(-1)).
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