Khondaker Afrina Hoque presented on the use of d orbitals in internal π bonding in silylamines. Silylamines contain a silicon atom bound to a nitrogen atom. The presentation discussed the orbital structures of nitrogen, silicon, and trisilylamine. The use of d orbitals in trisilylamine allows for pπ-dπ bonding, delocalization of nonbonding electrons over the entire system, and a planar triangular structure, resulting in shorter bond lengths, 120 degree bond angles, and lower basicity compared to trimethylamine which forms pπ-pπ bonds without d orbital involvement.

1. PRESENTATION ON
USE OF d ORBITALS IN INTERNAL ∏
BONDING IN SILYLAMINES

2. PRESENTED BY:-
Khondaker Afrina Hoque
ID:1114015
Reg:900048
Session:2o11-12

3. WELCOME TO MY
PRESENTATION

4. • Silylamines:- Silicon atom is bound to
nitrogen atom the materials are known
as silylamines or aminosilicones.
• e.g;- trisilylamine,
• triethylsilylamine etc.

5. Electronic configuration of
Nitrogen atom-ground state:
1s 2s 2px 2py 2pz
sp hybridization
Silicon atom-ground state:
1s 2s 2p 3s 3p
Silicon atom-excited sate:
1s 2s 2p 3s 3px 3py 3pz 3d
2 2 1 11
2
2 2 6 2 2
2 2 6 11 1 01
USE OF d ORBITALS IN INTERNAL ∏
BONDING IN SILYLAMINES

6. • Orbital structure of trisilylamine
Fig: Trisilylamine

7. Effects due to the use of “d-orbital” in
internal ∏ bonding.
Trysilylamine Trimithylamine

8. • p∏-d∏ bonding.
• Delocalisation of
nonbonding
electrons over the
entire system.
• Structure type:
planar triangular
• p∏-p∏ bonding.
• Delocalisation
doesn’t occur. Bcz
carbons has no
empty d orbitals.
• Structure type:
pyramidal

9. • Bond length: lower.
• Bond angle: 120.
• Basicity-lower.
• Bond length: Higher.
• Bond angle: 108.
• Baicity- higher.

10. Thanks to all…………………