2 research outputs found
Aggregation-Induced Emission Enhancement in Alkoxy-Bridged Binuclear Rhenium(I) Complexes: Application as Sensor for Explosives and Interaction with Microheterogeneous Media
The
aggregation-induced emission enhancement (AIEE) characteristics of
the two alkoxy-bridged binuclear ReÂ(I) complexes [{ReÂ(CO)<sub>3</sub>(1,4-NVP)}<sub>2</sub>(ÎĽ<sub>2</sub>-OR)<sub>2</sub>] (<b>1</b>, R = C<sub>4</sub>H<sub>9</sub>; <b>2</b>, C<sub>10</sub>H<sub>21</sub>) bearing a long alkyl chain with 4-(1-naphthylvinyl)Âpyridine
(1,4-NVP) ligand are illustrated. These complexes in CH<sub>2</sub>Cl<sub>2</sub> (good solvent) are weakly luminescent, but their intensity
increased enormously by almost 500 times by the addition of poor solvent
(CH<sub>3</sub>CN) due to aggregation. By tracking this process via
UV–vis absorption and emission spectral and TEM techniques,
the enhanced emission is attributed to the formation of nanoaggregates.
The nanoaggregate of complex <b>2</b> is used as a sensor for
nitroaromatic compounds. Furthermore, the study of the photophysical
properties of these binuclear ReÂ(I) complexes in cationic, cetyltrimethylammonium
bromide (CTAB), anionic, sodium dodecyl sulfate (SDS), and nonionic, <i>p-tert</i>-octylphenoxypolyoxyethanol (TritonX-100, TX-100),
micelles as well as in CTAB–hexane–water and AOT–isooctane–water
reverse micelles using steady-state and time-resolved spectroscopy
and TEM analysis reveals that the nanoaggregates became small and
compact size
Visible-Light Activation of the Bimetallic Chromophore–Catalyst Dyad: Analysis of Transient Intermediates and Reactivity toward Organic Sulfides
In
order to develop a new photocatalytic system, we designed a
new redox-active module (<b>5</b>) to hold both a photosensitizer
part, [Ru<sup>II</sup>(terpy)Â(bpy)ÂX]<sup><i>n</i>+</sup> (where terpy = 2,2′:6′,2′′-terpyridine and bpy = 2,2′-bipyridine),
and a popular Jacobsen catalytic part, salen–MnÂ(III), covalently
linked through a pyridine-based electron-relay moiety. On the basis
of nanosecond laser flash photolysis studies, an intramolecular electron
transfer mechanism from salen–Mn<sup>III</sup> to photooxidized
Ru<sup>III</sup> chromophore yielding the catalytically active high-valent
salen–Mn<sup>IV</sup> species was proposed. To examine the
reactivity of such photogenerated salen–Mn<sup>IV</sup>, we
employed organic sulfide as substrate. Detection of the formation
of a Mn<sup>III</sup>–phenoxyl radical and a sulfur radical
cation during the course of reaction using time-resolved transient
absorption spectroscopy confirms the electron transfer nature of the
reaction. This is the first report for the electron transfer reaction
of organic sulfide with the photochemically generated salen–Mn<sup>IV</sup> catalytic center