Abstract
The tridentate (ONNN')-chelator properties of the pyrrole-2-(o-hydroxyphenyl)carbaldimine dianion (L2_) were explored for the neutral penta-coordinate diorganosilicon complexes LSiRR/ (R,R/ = Ph, Ph; Ph, Me; Ph, tBu) where the ligand L occupies the ax-eq-ax sites in a distorted trigonal- bipyramidal arrangement arround the silicon atom, and for the neutral hexa-coordinate L2Si, that has a mer-coordination. Single-crystal X-ray diffraction analyses show an almost planar ligand backbone with a Si-N bond to the imine group that is shorter in hexa-coordinate L2Si than in pentacoordinate LSiRR'. In sharp contrast to the almost colorless neutral ligand LH2, both complexes show pronounced UV/Vis absorptions in the red-brown region that originate from HOMO - LUMO and HOMO-1 - LUMO transitions, and that are due to intra-ligand π-π transitions from the N-o- oxyphenylimine towards the imine moiety.
Original language | English |
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Pages (from-to) | 1571-1579 |
Number of pages | 9 |
Journal | Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences |
Volume | 64 |
Issue number | 11-12 |
DOIs | |
Publication status | Published - Dec 2009 |
Externally published | Yes |
Keywords
- Chelate
- Hypercoordination
- Pyrrole
- Schiff Base
- Time-dependent DFT
- UV/Vis
ASJC Scopus subject areas
- General Chemistry