MYTUTOR SUBJECT ANSWERS

182 views

Why are transition metal complexes coloured?

By definition, all transition metal ions have d orbitals. These are normally degenerate, lying at the same energy level as there is nothing to break the symmetry.

However, in the presence of ligands, the symmetry is broken and the orbitals split into different energy levels. This is due to differing alignment with the ligands resulting in a different electric repulsion from then lone pairs on the ligands.

For example, in an octohedral complex like [Cu(H2O)6]2+, the dx2-y2 and dz2 orbitals point directly at the ligands whereas the dxy, dxz and dyz orbitals all lie between the ligands. This means that the former experience greater electronic repulsion and are therefore raised in energy compared to the latter.

The split in energy levels means that electrons can be excited from the lower to the higher energy level by absorbing a photon. The energy of the this photon relates to its frequency by E=hf meaning that complexes absorb light of one partiular colour. They therefore transmit the complimentary colour and this happens to be in the visible light range so they appear coloured.

Zac T. A Level Chemistry tutor, A Level Further Mathematics  tutor, A...

5 months ago

Answered by Zac, an A Level Chemistry tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

80 SUBJECT SPECIALISTS

£22 /hr

Anuradha D.

Degree: Physics (Masters) - Durham University

Subjects offered: Chemistry, Physics+ 4 more

Chemistry
Physics
Music
Maths
Further Mathematics
-Personal Statements-

“Hello everyone! My name is Anuradha (you can call me Anu), and I am a Physics Undergrad at Durham. I have always had a “thing” for science and am so pleased to be studying it – and hope that I can give you all the support you need to ...”

£20 /hr

Eleni N.

Degree: Chemistry (Masters) - Edinburgh University

Subjects offered: Chemistry, Physics+ 2 more

Chemistry
Physics
Maths
Biology

“About Me: I am a Chemistry student at the University of Edinburgh, but I didn't always start out on this path. I spent my first two years at university persuing a  Biochemistry degree and I took every opportunity to do more science sub...”

£20 /hr

Eilidh F.

Degree: Natural Sciences (Bachelors) - York University

Subjects offered: Chemistry, Maths+ 2 more

Chemistry
Maths
Further Mathematics
Biology

“About me: My name is Eilidh (pronounced Aylee) and I am a student at the University of York. I study Natural Sciences specialising in Neuroscience, and have always loved both Science and Maths. I also reallyenjoy teaching, meeting new...”

MyTutor guarantee

About the author

Zac T.

Currently unavailable: until 03/10/2016

Degree: Natural Sciences (Bachelors) - Cambridge University

Subjects offered: Chemistry, Science+ 4 more

Chemistry
Science
Physics
Maths
Further Mathematics
Biology

“About me I am a student at the University of Cambridge where I study Natural Sciences, a course which allows me to maintain my interest in multiple areas of science and maths. I take modules in Chemistry, Physics, Earth Science and Ma...”

MyTutor guarantee

You may also like...

Posts by Zac

Find the shortest distance between the line L: x=1+t, y=1+2t, z=1-t and the point A: (2,3,4)

How can the average speedx of a gas molecule be derived?

Integrate (x+4)/(x^2+2x+2)

Why are transition metal complexes coloured?

Other A Level Chemistry questions

Define the term lattice energy. [2 marks]

Explain why ethanoic acid and hydrochloric acid of the same concentrations would give different pH readings

Define relative atomic mass.

What is a curly arrow?

View A Level Chemistry tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok