Red precipitae is obtained when ethanol solution of dimethylglyoxime is added to ammoniacal `Ni (II)`. Which of the following statement is not true?

Options

A. Dimethylgiyloxime functions as bidentate ligand.
B. Red complex has a square planar geometry
C. Complex has symmetrical H bonding
D. Red complex has a tetrahedral geometry

Answer

D

Explanation

The red coloured complex precipitated by `Ni^(2+)` and dimethylglyoxime form slightly ammoniacal solution is square plannar, not tetrahedral. However in the solid the square planar molecules are stacked on top of face and Ni-Ni interaction occurs. The Ni-Ni distance is `3.25 Å` . This was one of the earliest example of metal to metal bonding and in the sold Ni should be regarded as octahedrally coordinatd rather than square planar. The formation of this complex is used both for the detection and quantitative estimation of Ni. The dimethylgylyoxime loses a proton and forms a stable complex molecule. The complex is stabilized because two five membered chelae rings are formed and also by internal hydrogen bonding shown by dotted lines. The square planar complexes are generally red, brown or yellow in colour.