Contributions to the chemistry of higher-coordinate silicon [Elektronische Ressource] : synthesis, structure, and stereodynamics of new penta- and hexacoordinate silicon(IV) complexes / vorgelegt von Smaranda Cota

Anor326

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2010
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 7 Mo

Extrait

Contributions to the Chemistry of Higher-Coordinate Silicon:
Synthesis, Structure, and Stereodynamics of New Penta- and
Hexacoordinate Silicon(IV) Complexes




Dissertation zur Erlangung des
naturwissenschaftlichen Doktorgrades
der Julius-Maximilians-Universität Würzburg




Vorgelegt von
Diplom-Chemikerin
Smaranda Cota
aus Aiud/Rumänien





Würzburg 2010




















Eingereicht am: ……………………………
bei der Fakultät für Chemie und Pharmazie


1. Gutachter: ………………………
2.
der Dissertation

1. Prüfer: ………………………….
2.
3.
des Öffentlichen Promotionskolloquiums

Tag des Öffentlichen Promotionskolloquiums: ……………

Doktorurkunde ausgehändigt am: …………
2Abbreviations Index

Bn Benzyl
t-Bu tert-Butyl
i-Pr Isopropyl
Me Methyl
Ph Phenyl
Gly Glycine
Ala (S)-Alanine
Phe (S)-Phenylalanine
Val (S)-Valine
tert-Leu (S)-tert-Leucine
HMDS Hexamethyldisilazane
dbm Dibenzoylmethane
BSA Bis(trimethylsilyl)acetamide

d Day(s)
h Hour(s)
min Minute(s)
CIP Cahn-Ingold-Prelog
SP Square Pyramid
TBP Trigonal Bipyramid

DMSO Dimethylsulfoxide
THF Tetrahydrofuran
TMS Tetramethylsilane
NMR Nuclear Magnetic Resonance
br. Broad
s Singlet
d Doublet
t Triplet
m Multiple
3DEPT Distortionless Enhancement by Polarisation Transfer
VACP/MAS Variable Amplitude Cross Polarisation/Magic Angle Spinning
4Table of Contents
1 Introduction ...................................................................................................... 9
2 Aim................................................................................................................... 11
2.1 Syntheses of higher-coordinate silicon(IV) complexes with bidentate ligands
derived from α-amino acids....................................................................................... 11
2.2 Syntheses of higher-coordinate silicon(IV) complexes with acetylacetonato ligands
and acetylacetonato derivatives ................................................................................ 12
2.3 Syntheses of higher-coordinate silicon(IV) complexes with tridentate ligands..... 13
2.4 Syntheses of higher-coordinate silicon(IVith tetradentate ligands. 13
3 Syntheses ......................................................................................................... 15
3.1 Silylation of α-amino acids ........................................................................................ 15
3.2 Silylation of novel α-methyl substituted amino acids.............................................. 15
3.3 Syntheses of hexacoordinate silicon(IV) complexes with an SiO NC skeleton...... 16 4
3.4 Syntheses of hexacoordinate silicon(IVith an SiO skeleton ........... 16 6
53.5 Syntheses of zwitterionic λ Si-silicates .................................................................... 17
53.6 Syntheses of zwitterionic λ Si-silicates with novel α-methyl substituted amino
acids .......................................................................................................................... 21
3.7 Syntheses of hexacoordinate silicon(IV) complexes with an SiO N skeleton ....... 21 2 4
3.8 Syntheses of hexacoordinate silicon(IV) complexes containing cyanato-N and
thiocyanato-N ligands ............................................................................................. 24
3.8.1 Syntheses of hexacoordinate silicon(IV) complexes containing tridentate ligands
.......................................................................................................................... 24
3.8.2 Syntheses of hexacoordinate silicon(IV) complexes containing tetradentate
ligands .............................................................................................................. 27
4 NMR-Studies................................................................................................... 29
4.1 Behavior of trimethylsilyl N-(trimethylsilyl)alaninate in solution......................... 29
294.1.1 Si-NMR studies of trimethylsilyl N-(trimethylsilyl)alaninate in solution........ 29
54.2 Pentacoordinate silicon(IV) complexes with an SiO N C and SiON C skeleton... 30 2 2 3
294.2.1 Comparison of the Si NMR shifts of pentacoordinate silicon(IV) complexes
with bidentate ligands in the solid-state and solution ...................................... 30
294.2.2 Comparison of the IV) complexes
with tridentate ligands in th 31
4.3 Hexacoordinate silicon(IV) complexes with SiO , SiO NC, SiO N , SiO N C, 6 4 2 4 2 3
SiON C, and SiN C skeletons................................................................................. 32 4 5
294.3.1 Comparison of the Si NMR shifts of hexacoordinate silicon(IV) complexes
with an SiO N skeleton in the solid-state and solution................................... 32 2 4
294.3.2 Comparison of the IV) complexes
with SiO , SiO NC, SiO N , SiO N C, SiON C, and SiN C skeletons in the 6 4 2 4 2 3 4 5
solid-state and solution..................................................................................... 33
5 Crystal Structure Analyses............................................................................ 35
5.1 General Procedures.................................................................................................... 35
5.2 Hexacoordinate silicon(IV) complexes with an SiO NC skeleton........................... 35 4
5.2.1 Crystal structure of 33......................................................................................... 35
5.2.2 Crystal structure of 34 37
5.3 Hexacoordinate silicon(IV) complexes with an SiO skeleton................................. 38 6
5.3.1 Crystal structure of 35 38
5.3.2 Crystal structure of 36 39
55.4 Zwitterionic λ Si-silicates ......................................................................................... 40
5.4.1 Crystal structure of 38 40
5.4.2 Crystal structure of 39 42 43·CH CN............................................................................ 44 3
5.4.4 Crystal structure of 44......................................................................................... 45
5.4.5 Crystal structure of 46·C H ·1/2CH CN............................................................ 46 5 12 3
5.5 Hexacoordinate silicon(IV) complexes with an SiO N skeleton ............................ 48 2 4
5.5.1 Crystal structure of 50 48
65.6 Penta- and hexacoordinate silicon(IV) complexes with cyanato-N and
thiocyanato-N-ligands ............................................................................................. 49
5.6.1 Crystal structure of 54......................................................................................... 49
5.6.2 Crystal structure of 55 50
5.6.3 Crystal structure of 56 52
5.6.4 Crystal structure of 57 53
5.6.5 Crystal structure of 58 54
5.6.6 Crystal structure of 59......................................................................................... 56
5.6.7 Crystal structure of 60 57
5.6.8 Crystal structure of 62 58
5.6.9 Crystal structure of 63 59
5.6.10 Crystal structure of 64....................................................................................... 61
5.6.11 Crystal structure of 65·2CH CN........................................................................ 62 3
5.7 Comparison of selected bond lengths and angles of 38, 39, 43·CH CN, 44 and 3
46·C H ·1/2CH CN.................................................................................................. 63 5 12 3
5.8 Comparison of selected bond lengths and angles of 54 and 55 .............................. 65
5.9 Comparison of selected bond lengths and angles of 56, 57 and 58 ........................ 66
5.10 Comparison of selected bond lengths and angles of 59 and 60 ............................ 67
5.11 Comparison of selected bond lengths and angles of 62, 63 and 64 ...................... 68
6 Computational Studies................................................................................... 70
6.1 Computational studies of the neutral hexacoordinate silicon(IV) complex 50...... 70
6.2 Computational studies of the neutral pentacoordinate silicon(IV) complex 38 .... 71
7 Zusammenfassung.......................................................................................... 73
8 Summary ......................................................................................................... 77
9 Experimental Section ..................................................................................... 81
9.1 General Procedures.................................................................................................... 81
9.2 Syntheses ..................................................................................................................... 82
710 References and notes..................................................................................102
Appendix A: Crystal Structure Data............................................................