Extending Metal-Capped Polyynediyl Molecular Wires by Insertion of Inorganic Metal Units

Abstract

International audienceSeveral symmetric and asymmetric bis(metalla-diynediyl)ruthenium(II) complexes of the general formula trans-{LxRu}C≡CC≡C{Ru(dppe)2}C≡CC≡C{RuL′y} (Lx, L′y = (PPh3)2Cp, (dppe)Cp, (dppe)Cp*), containing Ru(dppe)2 as the central linking group, have been successfully synthesized and characterized spectroscopically. DFT calculations show that their HOMO's are delocalized over the Ru-C4-Ru-C4-Ru chain, suggesting that there is electronic interaction between the terminal RuLx groups through the C4 chains and the Ru(dppe)2 center. Limited electrochemical measurements reveal that the complexes undergo a series of five stepwise reversible or quasi-reversible oxidation processes

A Simple Fragment of Cyclic Acyldepsipeptides Is Necessary and Sufficient for ClpP Activation and Antibacterial Activity

“…Spectroscopic data are consistent with the solid‐state structure and are also comparable with those for the symmetrical complex trans ‐Ru{C≡CC≡C[Ru(dppe)Cp*]} 2 (dppe) 2 (herein in parentheses) 15. The IR spectrum of 4 shows two ν(C≡C) bands at 2037 and 1988 cm –1 (2012, 1969 cm –1 ).…”

Simplifying the conductance profiles of molecular junctions: the use of the trimethylsilylethynyl moiety as a molecule–gold contact

“…in which the metal acts as an insulating fragment, 11 these transRu(C≡CR) 2 (dppe) 2 -based systems offer a highly delocalised π-d-π electronic structure which spans the length of the molecular backbone. 12 Electrical measurements were performed using low- 80 coverage of the target molecule on a Au(111) gold substrate using an STM operating in the I(s) configuration, 13, † † with relatively high set point currents (20 nA) although no special care was taken to record data exclusively from flat Au(111) terraces to allow formation of both type A and type B contacts. 14 Under the same conditions, the reference compound 4, which contacts to each metallic surface in the junction through an amine moiety, gave rise to two well-resolved conductance peaks Recently, the formation of highly transmissive Au-C contacts from addition of Me 3 Sn-alkyl bonds to gold surfaces during STM-BJ measurements has been reported.…”

Syntheses and Structures of Buta-1,3-Diynyl Complexes from “on Complex” Cross-Coupling Reactions

“…Metal oligo/polyynyl M{(C≡C) n H}L x species have attracted significant interest over several decades, serving as scaffolds for the assembly of bi- [1][2][3][4][5][6][7][8][9][10][11][12][13] and poly-metallic [14][15][16][17][18][19][20][21][22][23][24][25][26] complexes, and as models and building blocks for metallomacrocycles, 15,[27][28][29] and metallo-polymers. [30][31][32][33][34][35] Detailed studies of the underlying electronic structure of this family of complexes have been undertaken, using a variety of computational and spectroscopic methods, often with a view to modelling the behavior of these prototypical molecular wires.…”

“…[30][31][32][33][34][35] Detailed studies of the underlying electronic structure of this family of complexes have been undertaken, using a variety of computational and spectroscopic methods, often with a view to modelling the behavior of these prototypical molecular wires. 21,[36][37][38][39] The terminal C≡CH moiety in polyynyl complexes M{(C≡C) n-1 C≡CH}L x offers a convenient entry point for the preparation of a wide range of polyynyl derivatives; however, the functionalization reactions of -(C≡C) n-1 C≡CH ligands are largely based on deprotonation and subsequent trapping with various electrophiles, 9,[40][41][42][43][44] including metal complex electrophiles. 45,46 To the best of our knowledge, the use of the Sonogashira cross-coupling reaction as a tool to prepare substituted derivatives of buta-1,3-diyl complexes was first demonstrated in 4 Scheme 1.…”