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- Synthesis, characterization and crystal structure of the bimetallic cyano-bridged [(η5-C5H5)(PPh3) 2Ru (μ-CN) Ru (PPh3) 2 (η5-C5H5)][PF6]Publication . Ornelas, Cátia; Gandum, Cláudia; Mesquita, José; Rodrigues, João; Garcia, M. Helena; Lopes, Nelson; Robalo, M. Paula; Nattinen, Kalle; Rissanen, Kari
- Synthesis, characterization and solid-state photoluminescence studies of six alkoxy phenylene ethynylene dinuclear palladium(II) rodsPublication . Figueira, João; Czardybon, Wojciech; Mesquita, José Carlos; Rodrigues, João; Lahoz, Fernando; Russo, Luca; Valkonen, Arto; Rissanen, KariA rare family of six discrete binuclear [PdCl(PEt3)2] phenylene ethynylene rods with alkoxy side chains (methoxy, ethoxy and heptoxy) have been developed, and their solid-state photoluminescence results have been presented and discussed. The shorter bridging ligands are of the general formula H–CuC– C6H2(R)2–CuC–H, where R = H, OCH3, OC 2H5, and OC7H15, whereas the longer ones are based on H– CuC–C6H4–CuC–C6H2(R)2–CuC–C6H4–CuC–H, where R = OCH3, OC 2H5. These ligands display increasing length in both the main dimension (backbone length) as well as the number of carbons in the side chains (R, alkoxide side chain) that stem from the central phenylene moiety. The X-ray crystal structures of two of the prepared complexes are reported: one corresponds to a shorter rod, 1,4-bis[trans(PEt3)2ClPd-CuC]-2,5-diethoxybenzene (6c), while the second one is associated with a longer rod, the binuclear complex 1,4-bis[trans-(PEt3)2ClPd-4-(–CuC–C6H4–CuC)]-2,5-diethoxybenzene (7c). All new compounds were characterized by NMR spectroscopy (1H, 13C{1H} and 31P{1H}) as well as ESI-MS(TOF), EA, FTIR, UV-Vis, cyclic voltammetry and solid-state photoluminescence. Our work shows the influence of the alkoxy side chains on the electronic structure of the family of binuclear Pd rods by lowering its oxidation potential. In addition to this, the increase of the length of the bridge results in a higher oxidation potential. Solid state photoluminescence results indicate that Pd complexes are characterized by a marked decrease in both the emission intensity and the fluorescence lifetime values as compared to their ligands. This behaviour could be due to some degree of ligand-to-metal charge transfer.
- A trinuclear aqua cyano-bridged ruthenium complex [{(η5-C5H5)(PPh3)2Ru(μ-CN)}2RuCl2(PPh3)(H2O)]PF6: synthesis, characterization and crystal structurePublication . Vertlib, Viatcheslav; Figueira, João; Mesquita, José; Rodrigues, João; Nättinen, Kalle; Rissanen, KariThe organometallic trinuclear aqua cyano-bridged complex [{(η5-C5H5)(PPh3)2Ru(µ-CN)}2RuCl2(PPh3)(H2O)]PF6 (1), in which the fragment [RuCl2(PPh3)(H2O)] acts as a bridge and an acceptor group between the two terminal cyclopentadienyl ruthenium cyano moieties, was isolated in moderate yield from the reaction of [(η5-C5H5)(PPh3)2RuCN] with [RuCl2(PPh3)3] in THF. To the best of our knowledge, compound 1 is one of the few examples of a trinuclear array of ruthenium fragments bridged by the nitrogen atom of the –C N– group (Ru–C N–Ru –N C–Ru) with a Ru-coordinated water molecule. The new aqua complex was structurally characterized by FTIR, 1H, 13C, and 31P NMR spectroscopy, mass spectrometry, elemental analysis, single-crystal X-ray diffraction, and cyclic voltammetry. The title complex crystallizes in a triclinic unit cell a = 17.3477(6) Å, b = 17.8551(5) Å, c = 18.2460(7) Å, α = 95.693(2)°, β = 111.648(2)°, and γ = 97.839(2)° in the space group P1 ¯ with Z = 2.