Metall‐Alkinyl‐σ‐Komplexe: Synthesen und Materialien

Abstract

Metallalkinylkomplexe bergen eine große Anziehungskraft für die Synthesechemie, die Strukturchemie und die Materialwissenschaften, sodass mittlerweile eine Vielzahl von Reaktionen zur M‐CC‐Verknüpfung mit einer ganzen Skala von Übergangsmetall‐ und Alkinylreagentien entwickelt wurde. Einige Methoden sind breit anwendbar, andere beschränken sich auf ein spezielles Metall oder Substrat. Wegen der linearen Geometrie der Alkinyleinheit und ihrem ungesättigten Charakter sind die Metallalkinyle attraktive Bausteine für molekulare Drähte und polymere metallorganische Materialien, die interessante physikalische Eigenschaften wie flüssigkristallines Verhalten, optische Nichtlinearität, Lumineszenz und elektrische Leitfähigkeit aufweisen können. Dieses einzigartige Spektrum an Eigenschaften steht als treibende Kraft hinter der intensiven Erforschung von Metall‐Alkinyl‐σ‐Komplexen. Die Entwicklung und Fortschritte insbesondere der letzten zehn Jahre werden in diesem Aufsatz zusammengefasst.

Bimetallic Catalysis using Transition and Group 11 Metals: An Emerging Tool for CC Coupling and Other Reactions

“…[10] The transmetalation reactions from alkynyl-copper(I) compounds is particularly easy because, at variance with other organometallic derivatives, these reagents are easily formed directly from the alkyne. This facilitates its use as transmetalating nucleophiles.…”

Mixed‐Transition‐Metal Acetylides: Synthesis and Characterization of Complexes with up to Six Different Transition Metals Connected by Carbon‐Rich Bridging Units

“…[1,2] In this respect, metal-containing alkynyls have been studied extensively due to their rigid structures, their stability, and, for example, their rich spectroscopic, photophysical, and electrochemical properties. [2] To control the structure and composition of multimetallic complexes, a prior synthesis of multifunctional bridging ligands is necessary that allows the stepwise metal coordination.…”

“…[1,2] In this respect, metal-containing alkynyls have been studied extensively due to their rigid structures, their stability, and, for example, their rich spectroscopic, photophysical, and electrochemical properties. [2] To control the structure and composition of multimetallic complexes, a prior synthesis of multifunctional bridging ligands is necessary that allows the stepwise metal coordination. Examples of such connectivities are 1,4-diethynylbenzene, [3,4] 1,3,5-triethynylbenzene, [5,6] 1-ethynyl-4-diphenylphosphinobenzene, [7] 5-ethynyl-2,2'-bipyridyl, [8] and 2,5-bisA C H T U N G T R E N N U N G (alkynyl) thiophenes.…”

Assembling Metal Clusters with Covalent Linkers: Synthesis and Structure of a Quasi‐Planar Pt18 Dendrimer Containing Five Clusters Connected by σ‐Alkynyl Spacers

“…Ordered structures with alternated metal clusters (or metal-metal-bonded bimetallic units [13] ) and conjugated s-alkynyl spacers [14][15] are extremely rare, [16] although of great potential interest. [10] This may be due to: 1) the tendency of metal clusters to undergo fragmentation or condensation, 2) their multiple and undistinguishable reactive positions, which facilitate the formation of complex mixtures of products, and 3) the preferred p interaction between the cluster and the alkynyl units [1,17] (the metal-alkynyl s linkage usually results in increased electronic delocalization [9] ). In this paper we show that tri-and hexanuclear platinum clusters with sizable bridging phosphide groups are suitable precursors to ordered materials.…”

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Transition-metal s-alkynyl derivatives [1] are emerging as potentially useful precursors for advanced materials due to their promising magnetic, [2] liquid-crystalline, [3] nonlinear optical, [4] and luminescence [5] properties. Moreover, there is considerable and increasing interest for their application in the synthesis of metal-containing macrocyclic, [6] dendritic, [7] and rigid-rod molecular frameworks with delocalized p systems.

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