Elena Lucenti

An acido-triggered reversible luminescent and nonlinear optical switch based on a substituted styrylpyridine: EFISH measurements as an unusual method to reveal a protonation-deprotonation NLO contrast†

Diphenyl-(4-{2-[4-(2-pyridin-4-yl-vinyl)-phenyl]-vinyl}-phenyl)-amine (DPVPA) constitutes a novel acido-triggered reversible luminescent and nonlinear optical switch. Remarkably, for the first time the Electric-Field Induced Second Harmonic generation (EFISH) technique is used to reveal a protonation-deprotonation NLO contrast.

H-Aggregates Granting Crystallization-Induced Emissive Behavior and Ultralong Phosphorescence from a Pure Organic Molecule

Solid-state luminescent materials with long lifetimes are the subject of ever-growing interest from both a scientific and a technological point of view. However, when dealing with organic compounds, the achievement of highly efficient materials is limited by aggregation-caused quenching (ACQ) phenomena on one side and by ultrafast deactivation of the excited states on the other. Here, we report on a simple organic molecule, namely, cyclic triimidazole (C9H6N6), 1, showing crystallization-induced emissive (CIE) behavior and, in particular, ultralong phosphorescence due to strong coupling in H-aggregated molecules. Our experimental data reveal that luminescence lifetimes up to 1 s, which are several orders of magnitude longer than those of conventional organic fluorophores, can be realized under ambient conditions, thus expanding the class of organic materials for phosphorescence applications.

Reproducible high-yield syntheses of [Ru3(CO)12], [H4Ru4(CO)12], and [Ru6C(CO)16]2− by a convenient two-step methodology involving controlled reduction in ethylene glycol of RuCl3·nH2O

Abstract [Ru3(CO)12], [H4Ru4(CO)12], and [Ru6C(CO)16]2− have been synthesized in reproducible high yields and under mild conditions (1 atm) by a two-step methodology involving (i) first carbonylation of RuCl3·nH2O dissolved in ethylene glycol to give a mixture of tri- and di-carbonyl ruthenium(II) species, probably of the kind [Ru(CO)3Cl2(ethylene glycol)] and [Ru(CO)2Cl2(ethylene glycol)x] (x=1, 2), and (ii) addition of specific amounts of alkali carbonates and further reductive carbonylation to give the desired ruthenium carbonyl cluster. The selectivity of the second step is controlled by the: (i) nature and quantity of the alkali carbonate (Na2CO3 or K2CO3); (ii) gas-phase composition (CO or CO+H2); (iii) temperature.

High-yield syntheses, under mild conditions, of various neutral and anionic ruthenium and osmium carbonyl clusters by controlled reduction in ethylene glycol of [M(CO)3Cl2]2 or MCl3 (MRu, Os) in the presence of Na2CO3 or K2CO3 ☆

Abstract [M 3 (CO) 12 ], [H 4 M 4 (CO) 12 ], [H 3 M 4 (CO) 12 ] − (MRu, Os) and [Ru 6 C(CO) 16 ] 2− have been synthesized in high yields by one-pot controlled reduction at atmospheric pressure of MCl 3 or [M(CO) 3 Cl 2 ] 2 , dissolved in t -amyl alcohol or ethylene glycol, working in the presence of alkali carbonates. The selectivity of the reduction is controlled by the: (i) nature and quantity of the alkali carbonate (Na 2 CO 3 or K 2 CO 3 ); (ii) nature of the solvent; (iii) gas-phase composition (CO or CO+H 2 ); (iv) temperature and (v) reaction time. Yields are so high and reaction conditions so mild that, in most cases, these new syntheses are more convenient than those previously reported either in solution or on the silica surface as reaction medium.

Surface Mediated Organometallic Synthesis: Formation of [H5Os10(CO)24]− by Hydrogenation of Silica-Supported [Os(CO)3(OH)2]n as a Springboard for a High-Yield Synthesis of [H4Os10(CO)24]2− Starting from α-[Os(CO)3Cl2]2 and Working in Ethylene Glycol Solution

AbstractNew high yield routes to the high nuclearity hydrido carbonyl clusters [H5Os10(CO)24]- and [H4Os10(CO)24]2-, model systems for the chemisorption of CO and H2 on metal surfaces, are reported. [H5Os10(CO)24]- is obtained in good yields by hydrogenation (1 atm) at 200°C of physisorbed [Os(CO)3(OH)2]n whereas in refluxing ethylene glycol solution, that is less acidic than the silica surface, [H4Os10(CO)24]2- is obtained in high yield starting from [Os(CO)3(OH)2]n or, more conveniently, from α-[Os(CO)3Cl2]2 in the presence of the stoichiometric amount of sodium carbonate. The quantitative equilibrium

Cyclic Triimidazole Derivatives: Intriguing Examples of Multiple Emissions and Ultralong Phosphorescence at Room Temperature

[{\text{H}}_{\text{4}} {\text{Os}}_{{\text{10}}} ({\text{CO}})_{24} ]^{2 - } \mathop {\underset { + {\text{H}}^{\text{ + }} } \leftrightarrows }\limits^{ + {\text{OH}}^ - } {\text{ }}[{\text{H}}_{\text{5}} {\text{Os}}_{{\text{10}}} ({\text{CO}})_{24} ]^ -

Metal free room temperature phosphorescence from molecular self-interactions in the solid state

is confirmed.

In Situ Electroluminescence Color Tuning by Thermal Deprotonation Suitable for Thermal Sensors and Anti-fraud Labels

Abstract The reductive carbonylation under 1 atm of CO of [Rh(CO) 2 Cl] 2 supported on a silica surface added with a base such as CH 3 CO 2 Na, Na 2 CO 3 or K 2 CO 3 , can be directed toward the formation of [Rh 4 (CO) 12 ], [Rh 6 (CO) 16 ] or K 2 [Rh 12 (CO) 30 ] by controlling (i) the nature and amount of base; (ii) the amount of surface water; (iii) the reaction time; (iv) the temperature. Physisorbed [Rh 6 (CO) 16 ] can also be prepared by direct controlled reductive carbonylation of RhCl 3 · n H 2 O supported on silica in the presence of well controlled amounts of CH 3 CO 2 Na. The neutral clusters [Rh 4 (CO) 12 ] and [Rh 6 (CO) 16 ] are easily recovered by extraction with dichloromethane whereas treatment of the generated silica-supported K 2 [Rh 12 (CO) 30 ] with tetrahydrofuran affords K 2 [Rh 12 (CO) 30 ] (by working under N 2 ) or K[Rh 5 (CO) 15 ] (by working under CO) in agreement with the easy conversion of these two clusters in solution. These efficient silica-mediated syntheses are comparable to conventional synthetic methods carried out in solution.