Photoexcitation of anthracene generates the spin triplet = (1 excited state. The X-band EPR (9.50GHz) spectrum from a frozen solution at 77K is shown below. The spectrum can be downloaded for analysis as a text file (q4_anthracene_ triplet.txt) containing field:intensity data that can be plotted in any standard software. (i) With the aid of a suitable energy level diagram, explain how many fully - allowed EPR transitions should be observed for each orientation of the molecule with respect to the applied magnetic field. [2 marks] (ii) Identify the z transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g = g. ). [2 marks] (iii) Identify the x transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g=g). [2 marks] (iv) Identify the y transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g = g). [2 marks] (v) Determine the axial (IDI) and rhombic (IEI) zero - field splitting parameters for the triplet state (MHz units). [2 marks] (vi) Determine the rhombicity parameter -) for the triplet state. [1 mark] (vii) A similar experiment on benzene gives |D| = 4.7GHz and [E] = 600MHz. Explain the difference in the magnitude of IDI between anthracene and benzene. [2 marks]

Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
icon
Related questions
Question

Cemetery

Photoexcitation of anthracene generates the spin triplet = (1 excited state. The X-band EPR (9.50GHz) spectrum from
a frozen solution at 77K is shown below. The spectrum can be downloaded for analysis as a text file (q4_anthracene_
triplet.txt) containing field:intensity data that can be plotted in any standard software. (i) With the aid of a suitable
energy level diagram, explain how many fully - allowed EPR transitions should be observed for each orientation of the
molecule with respect to the applied magnetic field. [2 marks] (ii) Identify the z transitions from the spectrum, and give
the separation between them in magnetic field units (mT) and in MHz (assume g = g. ). [2 marks] (iii) Identify the x
transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume
g=g). [2 marks] (iv) Identify the y transitions from the spectrum, and give the separation between them in magnetic
field units (mT) and in MHz (assume g = g). [2 marks] (v) Determine the axial (IDI) and rhombic (IEI) zero - field
splitting parameters for the triplet state (MHz units). [2 marks] (vi) Determine the rhombicity parameter -) for the
triplet state. [1 mark] (vii) A similar experiment on benzene gives |D| = 4.7GHz and [E] = 600MHz. Explain the difference
in the magnitude of IDI between anthracene and benzene. [2 marks]
Transcribed Image Text:Photoexcitation of anthracene generates the spin triplet = (1 excited state. The X-band EPR (9.50GHz) spectrum from a frozen solution at 77K is shown below. The spectrum can be downloaded for analysis as a text file (q4_anthracene_ triplet.txt) containing field:intensity data that can be plotted in any standard software. (i) With the aid of a suitable energy level diagram, explain how many fully - allowed EPR transitions should be observed for each orientation of the molecule with respect to the applied magnetic field. [2 marks] (ii) Identify the z transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g = g. ). [2 marks] (iii) Identify the x transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g=g). [2 marks] (iv) Identify the y transitions from the spectrum, and give the separation between them in magnetic field units (mT) and in MHz (assume g = g). [2 marks] (v) Determine the axial (IDI) and rhombic (IEI) zero - field splitting parameters for the triplet state (MHz units). [2 marks] (vi) Determine the rhombicity parameter -) for the triplet state. [1 mark] (vii) A similar experiment on benzene gives |D| = 4.7GHz and [E] = 600MHz. Explain the difference in the magnitude of IDI between anthracene and benzene. [2 marks]
Expert Solution
steps

Step by step

Solved in 2 steps

Blurred answer
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY