140-07-8Relevant articles and documents
Synthesis, characterization, electrochemistry and photophysical studies of tetranuclear ruthenium(II) complexes with two new spacers containing four 1,10-phenanthroline units as donor
Paul, Parimal,Tyagi, Beena,Natarajan
, p. 2283 - 2289 (2007/10/03)
Two novel tetranucleating spacers (BL1 and BL2) incorporating four 1,10-phenanthroline units have been synthesized and characterized. The reaction of these spacers with the building block cis-[Ru(bpy)2Cl2] resulted in the formation of tetranuclear complexes [{Ru(bpy)2}4BL1][PF 6]8.2H2O and [{Ru(bpy)2} 4BL2][PF6]8.2H2O. Cyclic voltammograms of these complexes show Ru(II)→Ru(III) oxidation at +1.25 V (vs SCE), and a few ligand-based reductions in the region -1.32 to -1.54 V. Both complexes show strong metal-to-ligand charge-transfer (MLCT) band in the visible region (457 and 456 nm). These complexes exhibit strong emission band (3MLCT) at 612 nm. The excited state life-times of both the complexes have been determined by laser flash photolysis experiments. The observed life-times, 252 ns for 1 and 226 ns for 2, and also electrochemical results, however suggest no intercomponent electronic interaction between the metal centers. The transient absorption difference spectra show bleaching of the MLCT band around 450 nm.
Synthesis, Characterization, Structures and Reactivities of Dinuclear Copper(I) Complexes of Three New Binucleating Hexadentate Ligands Having N2P4 or N2As4 Donor Sites
Khan, Mirza Mohammed Taqui,Paul, Parimal,Venkatasubramanian, Krishnan,Purohit, Sapna
, p. 3405 - 3412 (2007/10/02)
Three new binucleating hexadentate ligands having N2P4 or N2As4 donor sites, viz.N,N,N',N'-tetrakisethane-1,2-diamine (L1), its arsine analogue (L2) and 1,3-bis(bisaminomethyl)benzene (L3) have been prepared.The ligands react with to give the dinuclear four-co-ordinate copper(I) complexes 1)(PPh3)2Cl2>, 2)(PPh3)2Cl2> and 3)Cl2>.With the ligands yielded the three-co-ordinate dinuclear complexes 2 (L = L1, L2 or L3), which on treatment with NaN3, NH4NCS, KOH or NaBH4 (L = L1 or L3) gave dinuclear four-co-ordinate copper(I) complexes (X = N3, NCS, OH or BH4) via elimination of perchlorate and co-ordination of X.For the tetrahydroborato complexes, two hydrogen atoms of each BH4- ligand were co-ordinated to separate copper(I) centers.All the new ligands and complexes were characterized on the basis of elemental analysis, molar conductivity, IR spectra and 1H, 13C-(1H), 11B-(1H) and 31P-(1H) NMR spectral data.The molecular structures of 1)(PPh3)2Cl2> 1 and 3)Cl2> 3 were established by single-crystal X-ray diffraction , a = 11.711(2), b = 18.731(3), c = 10.080(1) Angstroem, α = 91.22(1), β = 107.45(1), γ = 78.11(1) deg, Z = 1, final R factor 0.040 (R'= 0.046) for 3715 observed reflections; 3, C64H64Cl2Cu2N2P4, triclinic, space group P1, a = 12.922(4), b = 19.161(1), c = 12.777(3) Angstroem, α = 93.11(1), β = 111.85(2), γ = 84.69(1) deg, Z = 2, final R factor 0.042 (R'= 0.046) for 5684 observed reflections>.
