CompuServe Thread

#pb

2 messages in this thread
#49648From: Larry JonesJul 14, 1993 3:37 PM
I am looking for some specific answers and I don't know if you've gotten the other messages: 1) how do I pi bond an olefin to a substituted dicyclopentadienyl titanocene metal center that has an attached growing polymer chain (I want to do a rotational study on the olefin using the excel macro to determine the optimum config.)…. more later…..
#49715From: Tom Slee [Hypercube]Jul 15, 1993 8:54 AM
Larry, > how do I pi bond an olefin to a titanocene… Really the only way is to sigma bond to each carbon of the olefin: HyperChem does not have dummy atoms that you could place at the centre of the bond. If this increases the number of bonds past twelve (the maximum) you may want to think of disconnecting the cyclopentadienyl rings from the metal. The consequences of doing this depend on your calculations. If you are doing semi-empirical calculations, then bonding information is not used (the molecule is just a bunch of nuclei and electrons). If you are doing molecular mechanics calculations on the whole system, then the energy and structure will be affected. If you leave the metal centre and rings fixed during the optimizations (by not having them selected) then they won't move, so the structure will be unaffected.