|
|
| (One intermediate revision by one other user not shown) |
| Line 1: |
Line 1: |
| In molecular [[spectroscopy]], the '''Birge–Sponer method''' or '''Birge–Sponer plot''' is a way to calculate the [[dissociation energy]] of a molecule. By observing transitions between as many [[Molecular vibration|vibrational energy levels]] as possible, for example through electronic or [[infrared spectroscopy]], the difference between the energy levels, <math>\Delta G_{v+\frac{1}{2}}=G(v+1)-G(v)</math> can be calculated. This sum will have a [[maximum]] at <math>v_{max}</math>, representing the point of bond dissociation; summing over all the differences up to this point gives the total energy required to dissociate the molecule, i.e. to promote it from the [[ground state]] to an unbound state. This can be written:
| | Her name is Judie. Doing ballet is what I do every weekend. Mississippi has always been my home and my parents live in close proximity. My job is a credit authoriser but soon I will be on this. Go to my web site to find out more: http://www.apansce.org/noticies/comprar-ugg.html<br><br>Feel free to visit my webpage [http://www.apansce.org/noticies/comprar-ugg.html ugg españa] |
| | |
| <math>D_0=\sum_{v=0}^{v_{max}} \Delta G_{v+\frac{1}{2}}</math>
| |
| | |
| where <math>D_0</math> is the dissociation energy. If a [[Morse potential]] is assumed, plotting <math>\Delta G_{v+\frac{1}{2}}</math> against <math>v+1/2</math> should give a straight line, from which it is easy to extract <math>v_{max}</math> from the [[Zero of a function|intercept]] with the x-axis. In practice, such plots often give curves because of unaccounted anharmonicity in the potential; furthermore, the low population of the higher states (or the [[Franck-Condon principle]]) makes it difficult to experimentally obtain data at high values of <math>v</math>. Thus the [[extrapolation]] can be inaccurate and only an upper limit for the value of the dissociation energy can be obtained.
| |
| | |
| This method takes its name from [[Raymond Thayer Birge]] and [[Hertha Sponer]], the two physical chemists that developed it.
| |
| | |
| == References ==
| |
| *{{cite book |title= Basic Atomic and Molecular Spectroscopy|last= Hollas |first=Michael |year=2002 |publisher= [[Royal Society of Chemistry]]|isbn= 9780854046676|page= 81}}
| |
| *{{cite book|title=Vibrational Spectroscopy: Theory and Applications|last=Sathyanarayana|first=D.N.|year=2007|publisher=New Age International|isbn=9788122415179|page=18}}
| |
| | |
| {{DEFAULTSORT:Birge-Sponer method}}
| |
| [[Category:Spectroscopy]]
| |
Latest revision as of 23:50, 28 October 2014
Her name is Judie. Doing ballet is what I do every weekend. Mississippi has always been my home and my parents live in close proximity. My job is a credit authoriser but soon I will be on this. Go to my web site to find out more: http://www.apansce.org/noticies/comprar-ugg.html
Feel free to visit my webpage ugg españa