Experimental study of the fluctuation theorem in a nonequilibrium steady state

The fluctuation theorem (FT) quantifies the probability of second law violations in small systems over short time scales. While this theorem has been experimentally demonstrated for systems that are perturbed from an initial equilibrium state, there are a number of studies suggesting that the theorem applies asymptotically in the long time limit to systems in a nonequilibrium steady state. The asymptotic application of the FT to such nonequilibrium steady states has been referred to in the literature as the steady-state fluctuation theorem (or SSFT). In this paper, we demonstrate experimentally the application of the FT to nonequilibrium steady states, using a colloidal particle localized in a translating optical trap. Furthermore, we show, for this colloidal system, that the FT holds under nonequilibrium steady states for all time, and not just in the long time limit, as in the SSFT

Synthesis and optical power limiting properties of heteroleptic Mo3S7 clusters

Substitution of the halide ligands in (Bu4N)2[Mo3S7X6] (X = Cl, Br) by diimine ligands, such as 4,4′-dimethyl-2,2′-bipyridine (dmbpy), 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen), affords the neutral heteroleptic clusters Mo3S7Cl4(dmbpy) (1), Mo3S7Br4(dmbpy) (2), Mo3S7Br4(bpy) (3), and Mo3S7Br4(phen) (4). Further substitution of the halide ligands in Mo3S7Br4(diimine) clusters by dmit (1,3-dithiole-2-thione-4,5-dithiolate) allows the preparation of the mixed diimine–dithiolene neutral cluster complexes Mo3S7(dnbpy)(dmit)2 (5, dnbpy = 4,4′-dinonyl-2,2′-bipyridine), Mo3S7(dcmbpy)(dmit)2 (6, dcmbpy = 4,4′-dimethoxycarbonyl-2,2′-bipyridine), and Mo3S7(dcbpy)(dmit)2 (7, dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid). The optical limiting properties of complexes 1–7 have been assessed by the open-aperture Z-scan technique at 570 nm, employing a nanosecond optical parametric oscillator. In order to investigate the effect of increasing the π-system, complexes 1–4, with the general formula Mo3S7X4(diimine), (X = Cl, Br), were compared to clusters 5–7, containing the dmit ligand. The influence of the metal content on the optical power limiting properties was also investigated by comparing the trinuclear series of complexes prepared herein with the bis(dithiolene) dinuclear cluster (Et4N)2[Mo2O2S2(BPyDTS2)2], which has been recently prepared by our group. All trinuclear clusters 1–7 are efficient optical limiters (σeff > σ0) with the threshold limiting fluence F15% decreasing on proceeding from dinuclear to trinuclear clusters and, generally, on extending the π-system.Financial support from the Spanish Ministerio de Economia y Competitividad (MINECO) (Grant CTQ2011-23157), UJI (research project P1.1B2013-19) and Generalitat Valenciana (Prometeo/2014/022 and ACOMP/2014/274) is gratefully acknowledged. The authors also thank Serveis Centrals d ’ Instrumentació Cientifica (SCIC), within Universitat Jaume, I for providing them with materials characterization facilities. D. R. thanks the Spanish Ministerio de Economía y Competividad for a predoctoral fellowship. M. G. H. thanks the Australian Research Council for support. M. S. acknowl- edges the NCN grant DEC-2013/10/A/ST4/0011

Synthesis, Optical, Electrochemical, and Theoretical Studies of Dipolar Ruthenium Alkynyl Complexes with Oligo(phenylenevinylene) Bridges

We thank the Australian Research Council (ARC), the National Natural Science Foundation of China (51432006), the Chinese Government Ministry of Education, and the Chinese Government State Administration of Foreign Experts Affairs (111 Project: B13025). M.P.C. thanks the ARC for an Australian Research Fellowship and C.Q. thanks CONICYT (Chile) for a Chile PhD Scholarship Abroad

Syntheses and Optical Properties of Azo-Functionalized Ruthenium Alkynyl Complexes

We thank the Australian Research Council (ARC), the National Natural Science Foundation of China (51432006), and the Chinese Government Ministry of Education and State Administration of Foreign Experts Affairs (111 Project: B13025) for financial support. M.P.C. thanks the ARC for an Australian Research Fellowship

Letter Ruling 99-1: Electronic Retailers

The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]­Cl_{(1–<i>p</i>)}{CCC₆H_5–<i>m</i>(CCFlu)_<i>m</i>}_(1+<i>p</i>)]­[PF₆]_<i>n</i> are reported (<i>n</i> = 0–1; <i>m</i> = 1–2; [M] = [Fe­(η⁵-C₅Me₅)­(κ²-dppe)] and <i>p</i> = 1 or [M] = [<i>trans</i>-Ru­(κ²-dppe)₂] and <i>p</i> = 0–1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru­(II) compounds in the 600–800 nm range (<i>Z</i>-scan) make them attractive nonlinear chromophores. Structure–property studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range

Linear and Third-Order Nonlinear Optical Properties of Fe(n5-C5Me5)(k2-dppe)- and trans-Ru(k2-dppe)2-Alkynyl Complexes Containing 2-Fluorenyl End Groups

The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]Cl(1–p){C≡CC6H5–m(C≡CFlu)m}(1+p)][PF6]n are reported (n = 0–1; m = 1–2; [M] = [Fe(η5-C5Me5)(κ2-dppe)] and p = 1 or [M] = [trans-Ru(κ2-dppe)2] and p = 0–1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru(II) compounds in the 600–800 nm range (Z-scan) make them attractive nonlinear chromophores. Structure–property studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range

Optical Tweezers manipulation of colloids and biopolymers: non-equilibrium processes

The Fluctuation Theorems (FTs) of Evans & Searles and of Crooks are fundamental theorems of modern thermodynamics that have been suggested to be of practical use to scientists and engineers. Non-equilibrium processes with energy fluctuations on the orde

Hydrodynamic Mobility of an Optically Trapped Colloidal Particle near Fluid-Fluid Interfaces

Using optical tweezers, we measure the anisotropic hydrodynamic mobility of a colloidal particle by tracking its thermal motion in an optical trap located near fluid-fluid interfaces, namely, liquid-vapor and liquid-liquid interfaces. The method require