Webmo

Question 1

Why was it necessary to run geometry optimizatoin before running an NMR or bond order?

Answer 1

if the NMR calculation is run on an non optimized structure, the results wont be accurate

Question 2

Clean up button??

Answer 2

It uses VSEPR to determine the number of Hs, ideal bond lengths, and angles.

Question 3

One advangate of using a lower level theory such as PM7 compared to using a higher level theory such as B3LYP.

Answer 3

PM7 is much faster

Question 4

The IR frequencies of the C=o bonds are also labeled. based purely on Webmo, would IR in the C=O region be useful for determinng whetehr the esterfication reaction did or did not work?

Answer 4

Yes, the peaks are far apart that we could look for the disappearance of the peak at 1728 and the appearacne of a peak at 1760 .

Question 5

Why would the clean up button lead to flawed results if used in between a geometry optimizaion and NMR calculations?

Answer 5

the cleanup button is a lower level than the actual calculatoin. using it would undo the work to get an accurate geometry which will skew future calculations.

Question 6

Why is it necessary to give enrgeies in hartees to 4 decimal palces?

Answer 6

1 hartee= 2600kJ. a tiny change in hartees mean a huge change in energy. in conract, 1 kJ is less than the margin of error of the calculations.

Question 7

How does webmo give different chemcial shifts for the 2 labelled benzens Hs?

Answer 7

the Hs are chemically equivalent due to symmetry and rotation. webmo looks at a signle conformation so misses out on that