Synthesis and characterization of complexes K2[Ni(CN)4] , K3[Fe(C2O4)3] and Cu(acac)2( IV, V and VI) with different structures and properties1. IntroductionThe aim of this experiment was to synthesize HgCo(SCN)4, [Ni(en)3]S2O3, NiCl2(PPh3)2, K2[Ni(CN)4], K3[Fe(C2O4)3] and Cu(acac )2 but only K2[Ni(CN)4], K3[Fe(C2O4)3] and Cu(acac)2 were synthesized and explained in this report. A characterization was then carried out on each of the 3 complexes synthesized by obtaining their UV-Vis spectrum. The UV-Vis spectrum of each complex would allow different properties to be identified and would help explain the observations made during their synthesis (e.g. their color and how they reacted).2. MethodTable 1: Synthesis of K2[Ni(CN)4]Amount of reagents used Method ObservationsNiSO4 • 7H2O: 6.00 gKCN: 3.01 g In 20 ml of water, NiSO4 • 7H2O was dissolved and the solution containing KCN (dissolved in 7 ml of water) was added to the Nickel solution. This solution was filtered and the precipitate was washed with small amounts of water. This precipitate was added to the KCN solution (dissolved in 3 ml of water). This solution was heated and stirred so that the crystals formed dissolved. It was heated again and left so that the crystals began to form again. This solution was then placed in an ice bath to enhance crystallization and the crystals were removed by filtration. The water was removed by drying the crystals in an oven at 100°C. A small amount of the sample was dissolved in water and the UV-Vis spectrum was obtained. Nickel(II) sulfate hexahydrate was used instead of heptahydrate. When the precipitate was added to the KCN solution, it turned dark red. As it was heated it darkened even more, but as crystals began to form the color changed to a light red. As the crystals dried, their color changed from light red-orange to a light yellow color. These crystals were dissolved in water for UV. -vis spectrum. The solution was yellow in color.Table 2: Synthesis of K3[Fe(C2O4)3]Quantity of reagents used Method Observations(NH4)2Fe(SO4)2 • 6H2O: 5.03 g For a solution of (NH4)2Fe( SO4) 2 • 6H2O (dissolved in 20 ml of water). 1 ml of sulfuric acid was added and stirred. Oxalic acid (dissolved in 25 ml of water) was also added and this combined solution was slowly heated to boiling, resulting in the formation of a yellow iron(II) oxalate precipitate. The liquid was decanted and 15 ml of hot water was added again to the precipitate, this was stirred and filtered. The precipitate (iron(II) oxalate) was transferred to another beaker and potassium oxalate solution (dissolved in 10 ml of hot water) was added...