March 29, 2024, 02:08:38 AM
Forum Rules: Read This Before Posting


Topic: Electronic Spectra  (Read 4604 times)

0 Members and 1 Guest are viewing this topic.

Offline newbie!

  • Regular Member
  • ***
  • Posts: 91
  • Mole Snacks: +0/-1
Electronic Spectra
« on: June 01, 2011, 06:18:04 AM »
from a course titled "environmental and analytical" butt eh sub title of this section of the course is "electronic spectra"

questions. pls note working is not show for many of these as i dont have the slightest clue how to tackle them... sadly :(

1) Briefly explain the effect of a strong π-acceptor ligand on the ligand field splitting parameter of a d3 octahedral complex?

2) Define the low spin ground state term for an Fe(III) complex.
i think this is the AET thing... with multiplicity and stuff...no idea how it works hough
Fe3 would be d5
i can do actahedral or tetrahedral splitting for high and low spin but i dont even think thats nesc fo this qestion.


3)The absorption spectrum for [Cr(NH3)6]3+ is shown below.


c) Identify the ground state term for the free Cr (III) ion and, using your results from (b), construct an Orgel diagram given that the relevant excited state for the free ion is 4P.

(d) Explain why the energies of the states identified in (b) are different from those for the free ion.

4)(a) Show that the splitting of the ground state atomic spectroscopic term for a d 2 configuration (Oh) is inverted for the d 8 configuration and sketch the correlation diagrams for both (including atomic and molecular term labels).
(b) What effect does the strength of field have on the correlations in a Tanabe-Sugano diagram for ground state terms derived from d 4 to d 7 configurations? You will need to calculate the ground state terms for each in low and high ligand fields.
(c) Using a simple orbital occupancy model, indicate the likelihood of the resulting molecular terms from d 4 complexes at high field strengths providing an absorption peak in UV-visible spectra? Provide an explanation to support your answer.

Sponsored Links