SYNTHESIS AND CHARACTERIZATION OF 1H-1,2,4-TRIAZOLE NICKEL(II) COMPLEXES WITH NITRATE, CHLORIDE, FLUOROBORATE, AND PERCHLORATE ANIONS

• Main Author: LISDIANA (NIM: 20515009), ANISYA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25636
• Institution: Institut Teknologi Bandung

<p align="justify">Nickel(II) complexes have been widely developed because it can be applied as antibacterial, anticancer, and catalyst. The complexes had a lot of chemical structures such as tetrahedral, square planar, and octahedral. The octahedral Ni(II) complexes was used to determine ligand field strength because the color of the complexes are in the visible to near infrared spectral range. The strength of the ligand field was obtained based on the energy of splitting d orbital from t2g to eg (&#916;o), then its were arranged into spectrochemical series. Strong field ligands such as 2,2'-bipyridine and 1,10-phenanthroline had &#916;o more than 12000 cm-1. While weak field ligands such as H2O had &#916;o less than 10000 cm-1. 1H-1,2,4-triazol (Htrz) ligand was an intermediate field ligand because the value of &#916;o lied between those values. The ligand was affected by anions. Therefore, in this study the four complexes of Ni(II) Htrz with nitrate, chloride, fluoroborate, and perchlorate anions had been synthesized. All the complexes obtained were purple and paramagnetic solids with uef about 2.84-3.35 BM indicating two unpaired electrons. The yield of Ni(II) triazole complexes with nitrate, chloride, fluoroborate, and perchlorate were 65%, 71%, 45%, and 62%, respectively. Three triazol ligands were coordinated on Ni central atom through N atoms. The Ni-N vibrations was shown in wave numbers of the infrared spectrum around 466-481 cm-1. Strong absorption at 634 cm-1 indicated that the triazole ligand has C2v symmetry which means bidentate as a bridging ligand between Ni(II) metal ions. The broad and strong absorption at ~ 3400 cm-1 indicated that each complexes contained water molecule. Each complexes had an anion-specific absorption on the infrared spectrum. Nitrate ion was characterized by N-O vibration at 829 cm-1. The B-F vibration band of fluoroborate ion was observed at 517 cm-1 and 1067 cm-1, while the Cl-O vibration of the perchlorate ion was shown at 627 cm-1 and 1088 cm-1. With anion nitrate and chloride, the general formula for complexes were [Ni(Htrz)3]A2.nH2O (A: NO3-, Cl- anions; n: 1 for nitrate and 3 for chloride). <br /> <br /> <br /> <br /> <br /> <br /> In aquadest solvent, the complexes [Ni(Htrz)3]A2 ionized into one Ni (Htrz)3]2+ and two A- counter anions represented from the conductivity of a complexes solution between 207-222 Scm2mol-1. The &#916;o value of the complexes solution were 11123-10869 cm-1 which nitrate contribution was greater than chloride. With Fluoroborate and Perchlorate anions, the Ni(II) Htrz complexes had the chemical formula [Ni(Htrz)2(trz)]A.3H2O (A: BF4-, ClO4- anions). One of Htrz ligand in the complexes was deprotonated into trz-. The two complexes were insoluble in water.<p align="justify">