homework help

1-Given that two π bonds conjugated together have a lower energy than two separate π bonds ( Fig . 1.32 ) and a C - H bond conjugated with π bond also lowers the energy ( Fig . 2.11 ) , explain why two C - H bonds conjugated to each other are not stabilised ?.

2- Explain why silylamines are weaker bases than ammonia and why

hexa-phenylsiloxane ( Ph3zSi )2O is linear .

3-Explain why , when the substituent Y in an allylic ether is an alkyl group the preferred conformation 2.106 , but when it is a carbonyl or nitrile group , the preferred conformation is 2.107

4-In the discussion about the H3 molecule, we could have combined the three atoms in a straight line. Show that there would be less bonding both in sigma1 and sigma2* and less antibonding in the sigma* orbital.