A Pd Halide Cluster from 1964: Pd₆Cl₈ Capped by Ring-Opened C₃Ph₃ Ligands from Oxidative Addition of Cyclopropenium Ions

Abstract

On the basis of a protocol from 1964 on the reaction of K 2 PdCl 4 , triphenylcyclopropenium chloride, and ethylene, the product was now identified as a Pd 6 Cl 8 cluster capped by μ 3 -η 1 :ηThe ligand is formed in a two-step reaction involving first the partial reduction of Pd(II) to Pd(0) by ethylene and second the ring-opening oxidative addition of the cyclopropenium ion, leading to a rare binding mode with one allyl and two alkyl bonds. Although the structure was not recognized at that time, this compound represents the first isolated organometallic Pd cluster compound.

Ionic Cyclopropenium-Derived Triplatinum Cluster Complex [(Ph3C3)2Pt3(MeCN)4]2+(BF4–)2: Synthesis, Structure, and Perspectives for Use as a Catalyst for Hydrosilylation Reactions

“…In this work, we focused on the study of Pt complexes with a tris­(phenyl)­cyclopropenium-derived cation. However, we employed synthetic methodology , completely different from that used for triangular Pt 3 -tropylium sandwich complexes: for example, that mentioned above for Tr 2 Pt 3 (MeCN) 3 (BF 4 ) 2 (Scheme A) . Key features of the methodology are the use of a starting cyclopropenium cation with weakly coordinating anion (WCA), which was BF 4 – ( 1 ), instead of the previously used halides and the mandatory use of acetonitrile, as a weakly binding 2e ligand for Pt atoms, driving the assembly of the complex.…”

“…Pd and, especially, Pt complexes with an aromatic cyclopropenium cationic ligand (Ar 3 C 3 + ) are among the least studied (Scheme B,C). Only a handful of works are known that describe two different reactions of tris­(phenyl)- or tris­(anisyl)-substituted cyclopropenium cations with Pd and Pt compounds. , The cyclopropenium cation is used in the form of a chloride or bromide salt, and the reactions proceed with opening of a three-membered cycle.…”

“…29,34,35 Pd and, especially, Pt complexes with an aromatic cyclopropenium cationic ligand (Ar Pt compounds. 36,37 The cyclopropenium cation is used in the form of a chloride or bromide salt, and the reactions proceed with opening of a three-membered cycle. Thus, in the reaction of cyclopropenium chloride with two types of Pd sources (Pd 2 (dba) 3 or an ethene Pd-complex as Pd(0) and K 2 PdCl 4 or PdCl 2 as Pd(II)) the anionic cluster Pd 6 Cl 8 (C 3 Ph 3 ) 2 is formed, which does not contain Pd−Pd bonds (Scheme 1B) 36 and is structurally related to the neutral cluster Pd 6 Cl 12 .…”

“…36,37 The cyclopropenium cation is used in the form of a chloride or bromide salt, and the reactions proceed with opening of a three-membered cycle. Thus, in the reaction of cyclopropenium chloride with two types of Pd sources (Pd 2 (dba) 3 or an ethene Pd-complex as Pd(0) and K 2 PdCl 4 or PdCl 2 as Pd(II)) the anionic cluster Pd 6 Cl 8 (C 3 Ph 3 ) 2 is formed, which does not contain Pd−Pd bonds (Scheme 1B) 36 and is structurally related to the neutral cluster Pd 6 Cl 12 . 38a This reaction was described back in 1964; 38b however, the exact structure was only established in 2017.…”

Investigation of Solvatomorphism and Its Photophysical Implications for Archetypal Trinuclear Au3(1-Methylimidazolate)3

“…In this context, having great interest in small organometallic clusters [ 21 , 22 ], closed-shell coinage-metal-based systems with fascinating photo-physical properties [ 23 , 24 ], we further consider the Au(I) imidazolate-type CTCs as a valuable platform to investigate the luminescence, inter- and intra-trimer metal-metal interactions and related supramolecular assembly. The simplest scaffold - Au 3 (MeIm) 3 was the first synthesized Au(I) imidazolate CTC by Burini in 1989 [ 7 ], but was not structurally determined until very recently by Ruiz et al in 2020 [ 20 ].…”