Science Journal of Chemistry 2014; 2(3): 17-26 Published online August 30, 2014 (http://www.sciencepublishinggroup.com/j/sjc) doi: 10.11648/j.sjc.20140203.12 ISSN: 2330-0981 (Print); ISSN: 2330-099X (Online) Synthesis, magnetic, spectral and biological studies of copper(II) complexes of 4-benzoyl-3-methyl-1-phenyl-2- pyrazolin-5-one N(4)-substituted thiosemicarbazones Ayman K. El-Sawaf 1, 2, * , Amal Abdel Fatah Nassar 3 , El-Sayed El-Samanody 1, 2 1 Chemistry Department, College of Science and Humanity Studies, Salman bin Abdulaziz University, AlKharj, KSA.11942 2 Chemistry Department, Faculty of Science, Minoufiya University, Shebin El-Kom, Egypt 3 Chemistry Department, College of Education for Girls, Salman bin Abdulaziz University, KSA Email address: elsawaf2008@yahoo.com (A. K. El-Sawaf) To cite this article: Ayman K. El-Sawaf, Amal Abdel Fatah Nassar, El-Sayed El-Samanody. Synthesis, Magnetic, Spectral and Biological Studies of Copper(II) Complexes of 4-Benzoyl-3-Methyl-1-Phenyl-2-Pyrazolin-5-One N(4)-Substituted Thiosemicarbazones. Science Journal of Chemistry. Vol. 2, No. 3, 2014, pp. 17-26. doi: 10.11648/j.sjc.20140203.12 Abstract: The synthesis and characterization of copper(II) complexes with 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5- one thiosemicarbazone and N(4)-substituted thiosemicarbazones are reported. Elemental analysis, molar conductivities, magnetic measurements and spectral (i.r., electronic, e.s.r., and n.m.r.) studies have been used to characterize the complexes. The i.r. spectra show that the thiosemicarbazones behave as bidentate ligands, either in the thione or thiolato form. Stereochemistries are proposed for the complexes on the basis of spectral and magnetic studies. Both the thiosemicarbazones and their complexes show either modest or no growth inhibitory activity against Aspergillus niger and Paecilomyces variotii. Keywords: Synthesis, Thiosemicarbazones, Characterization, Complexes, Stereochemistries, Antifungal 1. Introduction Transition metal ion complexes of thiosemicarbazones have been the subject of many articles [1- 4]. These compounds possess a range of biological applications that include antitumor [5], antifungal [6], antiviral [7], antibacterial [8] and antimalarial [9] activities. There have been an increasing number of studies featuring complexes of heterocyclic thiosemicarbazones, particularly thiosemicarbazones prepared from commercially available thiosemicarbazide [10, 11]. In addition, reports concerning iron(III), cobalt(II, III) [12], nickel(II), zinc(II) [13], and copper(II) [14] complexes of 4-formylantipyrine N(4)- methyl-, N(4)-dimethyl- and piperidylthiosemicarbazones. We describe here the preparation and characterization of copper(II) complexes with 4-benzoyl-3-methyl-1-phenyl-2- pyrazolin-5-one thiosemicarbazone, N(4)-methyl-, N(4)- dimethyl- and 3-piperidylthiosemicarbazones (HBATP4DH, HBATP4M, HBATP4DM and HBATPpip, respectively), 2. Experimental 2.1. Materials 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one, thiosemicarbazide, N(4)-methyl thiosemicarbazide and copper salts were purchased from Aldrich and used without further purification. 2.2. Synthesis of Ligands N(4)-Dimethyl thiosemicarbazide and 3- piperidylthiosemicarbazide were prepared following the method of Scovill [15]. Thiosemicarbazones were prepared by mixing equimolar amounts of 4-benzoyl-3-methyl-1- phenyl-2-pyrazolin-5-one and the desired thiosemicarbazide in anhydrous EtOH and stirring for 2 hrs. 2.3. Synthesis of Metal Complexes All the metal complexes were prepared by adding a solution of the copper(II) salt (0.002 mol) in EtOH (40 cm 3 ) was mixed with a solution of the desired thiosemicarbazone