We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

Cordination Compounds Essay

* Poly dentate ligands have flexi dentate character in the sense that all donors atoms may not form coordinate bonds with the central metal atom or ion. For example; EDTA which is the hexa dentate ligand also acts as tetra dentate or penta dentate in certain complexes. Similarly sulphate ion, which is a bi dentate ligand, also acts as a mono dentate ligand in certain complexes, e.g. in [Co(SO4)(NH3)5]Cl. * LABILE COMPLEXES;

* A complex in which the ligands can be easily replaced by other ligands is called a labile complex. * GEOMETRY OF [CuX4]2- IONS;
* The halide complex of Cu (2) shows two different stereo chemistries. In (NH4)2[CuCl4], [CuCl4]2- ion is square planar, but Cs2[CuCl4] and Cs2[CuBr4], the [CuX4]2- ions have a slightly squashed tetrahedral shape. Tetrahedral [CuCl4]2- ions are orange whereas, square planar [CuCl4]2- ions are yellow in colour. * GREATER STABILITY OF Co(+3) COMPLEXES THAN Co(+2) COMPLEXES; * Co+2 ions are very stable & are difficult to oxidise. Co+3 ions are less stable and are readily reduced by water to Co2+. In contrast Co(+2) are less stable and are readily oxidised to Co(+3) complexes, i.e. Co(3) are very stable. This is because CFSE of Co(+3) with d6 configuration is higher than Co(+2) with d7 configuration. * SIDGWICK THEORY OR EFFECTIVE ATOMIC NUMBER (EAN) RULE;

We will write a custom essay sample on Cordination Compounds specifically for you
for only $16.38 $13.9/page

Order now

* Sidgwick put forward a rule to explain the stability of complexes on the basis of effective atomic number as follows:- EAN of metal in complex= atomic number –oxidation state+2× co-ordination number A stable complex is formed if the EAN is equal to the atomic number of the next noble gas.

Thus, from the calculation given in the table below, [Fe(CN)6]4- is more stable than [Fe(CN)6]3- Though this rule is found to be applicable in many cases, yet it fails in no. Of cases as illustrated by last two examples given in the table below:

complex| Oxidation state| Atomic number | Co-ordination number| EAN| [Co(NH3)6]3+| +3| 27| 6| 27-3+2×6=36, i.e. [Kr]|
[Fe(CN)6]4-| +2| 26| 6| 26-2+2×6=36, i.e. [Kr]|
[PtCl6]2-| +4| 78| 6| 78-4+2×6=86, i.e. [Rn]|
[Fe(CN)6]3-| +3| 26| 6| 26-3+2×6=35|
[Ag(NH3)2]1+| +1| 47| 2| 47-1+2×2=50|

How to cite this page

Choose cite format:

Cordination Compounds. (2016, Mar 13). Retrieved from https://studymoose.com/cordination-compounds-essay

We will write a custom essay sample onCordination Compoundsspecifically for you

for only $16.38 $13.9/page
Order now

Sorry, but copying text is forbidden on this website. If you need this or any other sample, we can send it to you via email.

By clicking "SEND", you agree to our terms of service and privacy policy. We'll occasionally send you account related and promo emails.

Our customer support team is available Monday-Friday 9am-5pm EST. If you contact us after hours, we'll get back to you in 24 hours or less.

By clicking "Send Message", you agree to our terms of service and privacy policy. We'll occasionally send you account related and promo emails.
No results found for “ image
Try Our service