Question

A complex cation is formed by \[Pt\] (in some oxidation state) with ligands (in proper numbers so that coordination number of Platinum becomes six).
Which of the following can be its correct IUPAC name:
A.Diammine Ethylenediamine Dithiocyanato-S-platinum (II)
B.Diammine Ethylenediamine Dithiocyanato-S-platinate (IV) ion
C.Diammine Ethylenediamine Dithiocyanato-S-platinum (IV) ion
D.Diammine Bis(ethylenediamine)dithiocyanato-S-platinum(II) ion

Answer 1

Hint: It is indicated in the question that the complex is a cation and the central metal ion has a coordination number six.
-Each of these options have indicated oxidation number, so we can calculate the coordination number of each of the coordination complexes to see which one has six.

Complete step by step answer:
Widely complicated coordination complexes are composed of an ion or atom (which is usually a metal) and which are surrounded by an array of bound molecules or anions, termed as ligands. The atom with which the ligand is connected to the central metal ion, or atom is known as the donor atom. A characteristic complex is bound to a number of donor atoms, which could be different or the same. The term coordination refers to the coordinate covalent bonds which are formed between the ligands and the central atom.

There is a set of rules which are used for naming a coordination compound:
While naming a complex ion, the ligands are always supposed to be named before the metal ion.
Naming of ligands follows the following order: neutral, negative, positive. If there are more than one ligand of the same charge type, then they should be named in alphabetical order.

Frequently occurring monodentate ligands are given a prefix according to the number of occurrences: di-, tri-, tetra-, penta-, or hexa. Polydentate ligands (for instance ethylenediamine, oxalate) are given prefixes bis-, tris-, tetrakis-, etc.

Anions having the end -ido. This replaces the “e” present at the end, when the anion ends with “-ate” (for instance sulfate becomes sulfato) and it also replaces “-ide” (as in cyanide becomes cyanido).
Neutral ligands receives the usual name which was given to them, along with some exceptions: \[H_2O\] becomes aqua or aquo; \[~N{{H}_{3}}\] becomes ammine;\[NO\] becomes nitrosyl;\[CO\] becomes carbonyl.

Now we write the name of the central ion or atom. If the coordination complex is an anion, the name of the central atom will end in -ate, and its Latin name will be used if available (except for mercury).
If the oxidation state of the central atom needs to be specified, we are supposed to write it as a Roman numeral (or 0) in parentheses.
End with “cation” or “anion” as separate words, if the complex is cation or anion.

Now we will write each complex in the form of a chemical formula, which are given in the options.
Option (A): \[{{\left[ Pt\left( en \right){{\left( SCN \right)}_{2}}{{\left( N{{H}_{3}} \right)}_{2}} \right]}^{0}}\], which is not an ion. This is because the overall charge on the molecule is zero. This means that the charge on individual elements is balanced by each other.
Option (B): \[{{\left[ Pt\left( en \right){{\left( SCN \right)}_{2}}{{\left( N{{H}_{3}} \right)}_{2}} \right]}^{2+}}\]; it should not be palatinate, it should be platinum ion, the naming is incorrect.
Option (C): \[{{\left[ Pt\left( en \right){{\left( SCN \right)}_{2}}{{\left( N{{H}_{3}} \right)}_{2}} \right]}^{2+}}\], which is turned out to be the most appropriate option. As it has coordination number six and naming is also correct, as in, it is platinum ion, and not palatinate like the previous option.
Option (D): \[{{\left[ Pt{{\left( en \right)}_{2}}{{\left( SCN \right)}_{2}}{{\left( N{{H}_{3}} \right)}_{2}} \right]}^{2+}}\], the coordination number of this complex is \[8\]. And the question clearly says that it should be six.

So the correct option is option C.

Note: When we are specifically naming a transition-metal compound, it is necessary to specify which oxidation number the metal has. The oxidation number appears as a Roman numeral in parentheses after the cation.
-The name suffix ‘ate’ at the end of the name of a metal means that it is the anionic part of the complex. While it was clear in the question, that it is a positively charged complex.