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Abbildung 23 trans-Produkt der oxidativen Addition: trans-[Pd(Br)(C2H3)(PH3)2] 27
Abbildung 24 Dissoziative Zwischenprodukte [Pd(Br)(C2H3)(PH3)] 28 und [Pd(C2H3)(PH3)2]+ 29
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Abbildung 25 Dissoziation eines Liganden H3P Pd
Br
PH3
Pd
PH3 H3P
H3P Pd Br
PH3
Br
-Pd
PH3
Br + PH3
+ +
∆( NFDOPRO
∆( NFDOPRO
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Abbildung 26 Assoziative Umlagerung
H3P Pd Br
H2P Pd
PH3 Br
H3P
PH3
H3P Pd Br
H2P
PH3
Pd
PH3 PH3
Br + PH3
PH3 +
∆( NFDOPRO
∆( NFDOPRO
∆( NFDOPRO
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Abbildung 27 Umlagerung über eine fünffach koordinierte Zwischenstufe. Zwischenprodukt [Pd(Br)(C2H3)(PH3)3] 30 (oben) und Übergangszustand der Dissoziation
[Pd(Br)(C2H3)(PH3)3] (unten).
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Abbildung 28 Energieprofil der oxidativen Addition mit anschließender cis-trans-Umlagerung [kcal/mol]. (Normiert auf Tetrakisphosphanpalladium)
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PH3 Pd PH3 PH3 H3P
H3P Pd PH3
PH3
H3P Pd PH3
H3P Pd PH3
Br
Br H3P Pd
PH3
Pd
PH3 Br
Pd
PH3 H3P
+
H3P Pd Br
H2P PH3
Pd
PH3 PH3
Br
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