Discussion:
Recrystallisation was performed to purify the "[Ni" ("O,O '-ONO" )_"2" ("N,N,N ',N '-tetrameen" )"]" product. These green powder extracted from filtration was prone to impurities such as unreacted "[" "K" _"4" ["Ni" ("N-N" "O" _"2" )_"6" ]"." "H" _"2" "O" and "KN" "O" _"2" . As the product was dissolved in hot ethanol solvent and slowly cooled to crystallise, the impurities would remain dissolved rather than being solidified. Thus, the different solubilities of the green complex at disparate temperature had facilitated its isolation. This method was relatively simple to perform, accompanied with effective maximisation of purity and yield of the nickel complex.
In the experiment, it was notable that the impure green nickel complex appeared as dull green fine powder, and the pure product after recrystallisation were bright green particles where some were clearly crystalline. This observation confirmed the removal of solvents or impurities from the green complex. However, considering the IR spectrum of the complex in figure 4, since some of the IR peaks of "KN" "O" _"2" overlapped with that of the shifted NO stretches within the complex, they were not easily distinguished.
According to the spectrochemical series, the nitro …show more content…
Therefore, ν_as and ν_s would both be raised upon coordination with respect to free nitrite ions1, and according to figure 1, these features were possessed by "[Ni" ("N" "O" _"2" )_"2" ("en" )_"2" "]" which was thus a nitro complex. This was also evidenced in its red colour and its shorter λ_max of UV-visible absorption relative to other complexes. Here, the NO_2^- ions would be bound with the N end, above and below the plane of "[Ni" ("en" )_"2" ]^"2+" , exerting a stronger ligand field than other
Recrystallisation was performed to purify the "[Ni" ("O,O '-ONO" )_"2" ("N,N,N ',N '-tetrameen" )"]" product. These green powder extracted from filtration was prone to impurities such as unreacted "[" "K" _"4" ["Ni" ("N-N" "O" _"2" )_"6" ]"." "H" _"2" "O" and "KN" "O" _"2" . As the product was dissolved in hot ethanol solvent and slowly cooled to crystallise, the impurities would remain dissolved rather than being solidified. Thus, the different solubilities of the green complex at disparate temperature had facilitated its isolation. This method was relatively simple to perform, accompanied with effective maximisation of purity and yield of the nickel complex.
In the experiment, it was notable that the impure green nickel complex appeared as dull green fine powder, and the pure product after recrystallisation were bright green particles where some were clearly crystalline. This observation confirmed the removal of solvents or impurities from the green complex. However, considering the IR spectrum of the complex in figure 4, since some of the IR peaks of "KN" "O" _"2" overlapped with that of the shifted NO stretches within the complex, they were not easily distinguished.
According to the spectrochemical series, the nitro …show more content…
Therefore, ν_as and ν_s would both be raised upon coordination with respect to free nitrite ions1, and according to figure 1, these features were possessed by "[Ni" ("N" "O" _"2" )_"2" ("en" )_"2" "]" which was thus a nitro complex. This was also evidenced in its red colour and its shorter λ_max of UV-visible absorption relative to other complexes. Here, the NO_2^- ions would be bound with the N end, above and below the plane of "[Ni" ("en" )_"2" ]^"2+" , exerting a stronger ligand field than other