Unsymmetrisch gebaute (Pd – Pd)‐Zweikernkomplexe mit CO, CNR, SO₂ und C₂(CO₂Me)₂ als Brückenliganden

Abstract

Die Reaktion der Cyclopentadienyl-und Halogen-verbruckten Zweikernkomplexc (p-C5H5)(p-X)Pd2(PEtl)2 (1 a, b) und (p-C5H5)(p-X)Pd2(PiPr3)? (Za, b) mit CO, CNR (R = CHI, C6H5, p-CHIC&), SO2 und C2(C02Me)2 fuhrt nahezu quantitativ zu den Verbindungen C5H5(PR3)Pd(p-E)Pd(PR3)X (3,4,6-ll), in denen der Bruckenligand E [CO, CNR, SO2, C2 (C02Me) Das ursprungliche Ziel der vorliegenden Arbeit war herauszufmden, ob in den Verbindungen (p-CsH5)(p-X)-Pd2(PR3)z der Briickenligand X auch gegen eine neutrale Lewis-Base wie 2.B. CO austauschbar ist. Eine Reaktion nach GI. (1) wiirde zu kationischen CO-verbriickten Zweikernkomplexen fuhren, von denen bisher nur wenige Vertreter bekannt sind.Uberraschenderweise verlHuft jedoch die Reaktion von CO (und ebenso von Isonitrilen, SO2 und Acetylendicarbonsauredimethylester) mit Verbindungen des Typs (pCsHs)(p-X)PddPR3)2 vollig anders als in GI.

Palladium carbonyl complexes

“…113 The analogous initial compound containing an acetate instead of a bromide bridge reacts with CO also with formation of complex 32. 114 Complexes 32a,b have been characterised by IR spectroscopy (n CO = 1804 and 1828 cm 71 respectively) and NMR spectroscopy on different nuclei. The.…”

Mechanistic Studies of the Insertion of CO2into Palladium(I) Bridging Allyl Dimers

“…This is in contrast to the well-characterized reactivity of monomeric η 1 -Pd allyls, which can act as nucleophiles, and monomeric η 3 -Pd allyls, which can act as electrophiles . Figure depicts a general classification scheme for Pd I bridging allyl dimers and related molecules that have been reported. ,− Complexes supported by bridging cyclopentadienyl (types IV – VII ) and indenyl ligands (types VIII – IX ) are included in Figure because spectroscopic, crystallographic, and theoretical evidence indicates that the cyclopentadienyl and indenyl ligands bridge the Pd centers in an analogous fashion to conventional bridging allyl ligands. ,, …”

A new synthesis for thermolabile low-valent palladium complexes by electron transfer reactions from nickel(0) to palladium(II) compounds

“…Dimeric Pd(I) complexes have been intensively investigated due to their importance in homogeneous catalytic reactions, as model complexes for clusters and for metallic surfaces [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Dimeric Pd(I) complexes, however, consisting only of the Pd 2 Cl 2 core and olefins (e.g.…”