Synthesis, characterization, electrochemistry and photophysical studies of tetranuclear ruthenium(II) complexes with two new spacers containing four 1,10-phenanthroline units as donor

Content Provider	Semantic Scholar
Author	Paul, Parimal Tyagi, Beena Natarajan, Palani
Copyright Year	2003
Abstract	Two novel tetranucleating spacers (BL 1 and BL 2 ) incorporating four 1,10-phenanthroline units have been synthesized and characterized. The reaction of these spacers with the building block cis-[Ru(bpy) 2 Cl 2 ] resulted inthe formation of tetranuclear complexes [{Ru(bpy) 2 } 4 BL 1 ][PF 6 ] 8 .2H 2 O and [{Ru(bpy) 2 } 4 BL 2 ][PF 6 ] 8 .2H 2 O. 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 ( 3 MLCT) 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.
Starting Page	2283
Ending Page	2289
Page Count	7
File Format	PDF HTM / HTML
Volume Number	42
Alternate Webpage(s)	http://nopr.niscair.res.in/bitstream/123456789/20736/1/IJCA%2042A(9)%202283-2289.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article