Metathesis Approach to Linkage of Two Tetraplatinum Cluster Units: Synthesis, Characterization, and Dimerization of [Pt4(μ-OCOCH3)7(μ-OCO(CH2)nCH=CH2)] (n = 0–3)

Abstract

Reaction of [Pt4(μ-OCOCH3)8] (1) with 1 equiv of acrylic acid led to the selective monosubstitution of one of the four in-plane acetates in 1, affording [Pt4(μ-OCOCH3)7(μ-OCOCH=CH2)] (2a), whereas treatment with excess amounts of acrylic acid resulted in a full-substitution of four in-plane acetates, yielding [Pt4(μ-OCOCH3)4(μ-OCOCH=CH2)4] (3). Similarly, monosubstituted heptaacetate complexes [Pt4(μ-OCOCH3)7{μ-OCO(CH)nCH=CH2}] (2b–2d: n = 1–3) were prepared. Catalytic intermolecular coupling reactions of 2c and 2d assisted by Grubbs’ catalysts gave the desired dimers [{Pt4(μ-OCOCH3)7}2{μ-OCO(CH2)nCH=CH(CH2)n(μ-OCO)}] (6c: n = 2; 6d: n = 3).

Recent Research Progress in Automotive Exhaust Gas Purification Catalyst

“…A Pt 4 polynuclear complex ([Pt 4 (l-OC-OCH 3 ) 8 ]) [8] was selected as a basic unit. Basic units were connected by a ligand exchange reaction using dicarboxylic acid [9], and were purified. The Pt 8 (2 connected basic units) and the Pt 12 (3 connected basic units) were synthesized in this procedure.…”

Supramolecular assemblies of multi-nuclear transition metal complexes: Synthesis and redox properties

“…amides [56], thiophosphite [57], pyridine [58], and so on [59], whereas the four out-plane acetate ligands of 29 remained intact. Simple addition of a half equivalent of dicarboxylic acid, which was thought to be the most straightforward synthetic route of its dimer, resulted in the formation of insoluble precipitates, presumably due to uncontrolled full substitution [60]. Thus, Mashima et al synthesized four amidinate complexes of tetraplatinum that were used for preparing supramolecular assemblies containing a tetraplatinum core [61,62].…”

“…The coupling reaction of organic functional groups attached to each metal cluster unit is a powerful tool for preparing supramolecules [95]. An olefin metathesis approach to construct dimer clusters was first reported by Mashima et al [60]. An equatorially-bridged dimer complex respectively (eqs 9 and 10) [99].…”

Rational Synthesis of Supramolecular Assemblies Based on Tetraplatinum Units: Synthesis, Characterization, and Selective Substitution Reactions of Four Different Pt4 Clusters

“…Selective replacement of the inplane acetates of 1, however, is difficult to control, which results in the precipitation of insoluble black Pt compounds. [29] We hypothesized that the introduction of appropriate nonlabile ligands to 1 would allow us to design and synthesize systematic architectures on 1 as suitable building blocks for producing oligomeric assemblies. In the present study, we prepared trans-and cis-capped bis(amidinate) Pt 4 complexes as well as mono-and tri-capped Pt 4 complexes (Figure 1), the characterization and fundamental replacement reactions of which, along with the construction of oligomeric supramolecules, were fully explored.…”