Charge delocalization vs localization in carbon-rich iron mixed-valence complexes: A subtle interplay between the carbon spacer and the (dppe)Cp*Fe organometallic electrophore

Metallodendrimers in three oxidation states with electronically interacting metals and stabilization of size-selected gold nanoparticles

“…After separation, the organic phase was dried with anhydrous Na 2 SO 4 , and the solvent was removed in vacuo, which gave a deep orange solid that was washed three times with 300 ml diethyl ether to remove the excess free ligands. This procedure yielded the 'click' dendrimer as an orange solid (89.2 mg, 60%) Oxidation of the complex 6B to 6B(PF 6 ) 27 . The dendrimer 6B (82 mg, 2 Â 10 À 3 mmol, 1 equiv.)…”

“…The redox-rich iron centres in the chosen system are Cp à Fe II (dppe)-alkynyl units (Cp à ¼ Z 5 -C 5 Me 5 , dppe ¼ 1,2-bis(diphenylphosphino) ethane) 24 that are isolobal to ferrocene and linked in meta position of an aryl bridge. In 1,3,5-trimetallaalkynylbenzene derivatives [24][25][26][27] , and in such Cp à Fe II (dppe) derivatives in particular 25,26 , it has been shown by density functional theory calculation and electrochemistry that, unlike in the 1,3,5-triferrocenylalkynylbenzene derivatives 28 , the three metals are electronically communicating. We synthesize the dendrons with only two iron-ethynyl groups in 1,3 position, leaving the third ethynyl position free for binding to the dendritic core either by Sonogashira coupling 29,30 or copper-catalysed azide-alkyne cycloaddition (CuAAC, 'click') reactions [31][32][33] with appropriately functionalized dendritic core termini.…”

Conformational Tuning of the Intramolecular Electronic Coupling in Molecular‐Wire Biruthenium Complexes Bridged by Biphenyl Derivatives

“…[21][22][23][24][25][26][27][28][29][30][31][32][33] Since the bridging ligands play an important role in tuning the ET properties of MV complexes, ranging from localization to delocalization, the synthesis of such compounds with various bridgingl igands has attracted considerable interest. [19] Recently,a ni mportant aspect of developing the [ML n (bridge)ML n ] system is controlling the electronic delocalization in the ground state of the MV form and the metal-versus-ligand character of the redox processes to yield am etal-centered or bridge-centered process. [34][35][36][37] In at hree-state model,i ntramolecular CT between two metal centers may occur by the superexchange mechanism, the hopping mechanism, [36,[38][39][40][41][42] or bridge-localized states over the bridge.…”

Refining the Interpretation of Near‐Infrared Band Shapes in a Polyynediyl Molecular Wire

“…[4] Although impressively long polyynediyl complexes are known, [2] the greatest concentration of work has focused on the properties of diynediyl-bridged (m-C CC C) d 6 /d 6 transition metal complexes, which have been synthesised, characterised, and investigated in their various electrochemically accessible redox states. [1,3,[5][6][7][8][9][10][11][12] The degree of delocalisation along the [{L n M}A C H T U N G T R E N N U N G (m-C CC C)A C H T U N G T R E N N U N G {ML n }] backbone, and hence the nature of the redox-derived products, is sensitive to the identity of the metal end-capping group.…”