Simultaneously multiply-configurable or superposed molecular logic systems composed of ICT (internal charge transfer) chromophores and fluorophores integrated with one- or two-ion receptors

Integrated "ICT chromophore-receptor" systems show ion-induced shifts in their electronic absorption spectra. The wavelength of observation can be used to reversibly configure the system to any of the four logic operations permissible with a single input (YES, NOT, PASS 1, PASS 0), under conditions of ion input and transmittance output. We demonstrate these with dyes integrated into Tsien's calcium receptor, 1-2. Applying multiple ion inputs to 1-2 also allows us to perform two- or three-input OR or NOR operations. The weak fluorescence output of 1 also shows YES or NOT logic depending on how it is configured by excitation and emission wavelengths. Integrated "receptor(1)-ICT chromophore-receptor(2)" systems 3-5 selectively target two ions into the receptor terminals. The ion-induced transmittance output of 3-5 can also be configured via wavelength to illustrate several logic types including, most importantly, XOR. The opposite effects of the two ions on the energy of the chromophore excited state is responsible for this behaviour. INHIBIT and REVERSE IMPLICATION are two of the other logic types seen here. Integration of XOR logic with a preceding OR operation can be arranged by using three ion inputs. The fluorescence output of these systems can be configured via wavelength to display INHIBIT or NOR logic under two-input conditions. The superposition or multiplicity of logic gate configurations is an unusual consequence of the ability to simultaneously observe multiple wavelengths.     

Ruthenium(II) dendrimers containing carbazole-based chromophores as branches

Three new luminescent and redox-active Ru(II) complexes containing novel dendritic polypyridine ligands have been synthesized, and their absorption spectra, luminescence properties (both at room temperature in fluid solution and at 77 K in rigid matrix), and redox behavior have been investigated. The dendritic ligands are made of 1,10-phenanthroline coordinating subunits and of carbazole groups as branching sites. The first and second generation species of this novel class of dendritic ligands (L1 and L2, respectively; see Figure 1 for their structural formulas) have been prepared and employed. The metal dendrimers investigated are [Ru(bpy)(2)(L1)](2+) (1; bpy = 2,2'-bipyridine), [Ru(bpy)(2)(L2)](2+) (2), and [Ru(L1)(3)](2+) (3; see Figure 2). For the sake of completeness and comparison purposes, also the absorption spectra, redox behavior, and luminescence properties of L1 and L2 have been studied, together with the properties of 3,6-di(tert-butyl)carbazole (L0) and [Ru(bpy)(2)(phen)](2+) (4, phen = 1,10-phenanthroline). The absorption spectra of the free dendritic ligands show features which can be assigned to the various subunits (i.e., carbazole and phenanthroline groups) and additional bands at lower energies (at lambda > 300 nm) which are assigned to carbazole-to-phenanthroline charge-transfer (CT) transitions. These latter bands are significantly red-shifted upon acid and/or zinc acetate addition. Both L1 and L2 exhibit relatively intense luminescence at room temperature in fluid solution (lifetimes in the nanosecond time scale, quantum yields of the order of 10(-2)-10(-1)) and at 77 K in rigid matrix (lifetimes in the millisecond time scale). Such a luminescence is assigned to CT states at room temperature and to phenanthroline-centered pi-pi triplet levels at 77 K. The room-temperature luminescence of L1 and L2 is totally quenched by acid or zinc acetate. The metal dendrimers exhibit the typical absorption and luminescence properties of Ru(II) polypyridine complexes. In particular, metal-to-ligand charge-transfer (MLCT) bands dominate the visible absorption spectra, and formally triplet MLCT levels govern the excited-state properties. Excitation spectroscopy evidences that all the light absorbed by the dendritic branches is transferred with unitary efficiency to the luminescent MLCT states in 1-3, showing that the new metal dendrimers can be regarded as efficient light-harvesting antenna systems. All the free ligands and metal dendrimers exhibit a rich redox behavior (except L2 and 3, whose redox behavior was not investigated because of solubility reasons), with clearly attributable reversible carbazole- and metal-centered oxidation and polypyridine-centered reduction processes. The electronic interaction between the carbazole redox-active sites of the dendritic ligands is affected by Ru(II) coordination.     

The pyridyl-tag strategy applied to the hydrocarbon/perfluorocarbon phase-switching of a porphyrin and a fullerene

A new hydrocarbon/perfluorocarbon phase-switching strategy based on coordination of pyridyl-tagged molecules to a highly fluorinated dicopper-carboxylate complex possessing two accessible axial coordination sites is described. When a chloroform solution of the tetrapyridyl-substituted porphyrin 3 (0.1 mM, 2 mL) is layered on a perfluorodecalin solution of 2 (3.25 mM, 1.5 mL), complete extraction of the porphyrin into the fluorous phase is observed after 30 min of stirring. Quantitative release of both the porphyrin and 2 is achieved simply by adding excess THF to the biphasic system, the THF acting as a pyridine competing ligand. The recovered perfluorocarbon solution containing 2 can be reused for another complexation with the same efficiency. The scope of this approach is emphasized by the phase-switching of a dipyridyl-substituted fullerene, another example of a molecule for which solubilization in perfluorocarbons is very challenging.     

4‐Anilino‐3‐nitro­pyridine

The structure of the title compound, C₂₂H₁₈N₆O₄, (I), comprises two unique mol­ecules that separately form hydrogen‐bonded polymer chains via N—H?N interactions. Molecular independence arises due to a difference in the dihedral angles between the linked rings, i.e. 52.19 (4) and 46.17 (5)°.     

Reversible hydrocarbon/perfluorocarbon phase-switching of [Ru(bipy)3]2+ driven by supramolecular heteromeric fluorous carboxylate-carboxylic acid H-bond interactions

The Ru(bipy)(3) dication is efficiently and reversibly transferred into perfluorocarbons due to the formation of a highly fluorophillic hydrogen-bonded fluorous carboxylate-carboxylic acid counter-anion, whilst retaining key luminescence and photosensitizer characteristics, for example in singlet oxygen production.     

1‐(4‐Chloro­phenyl­sulfanyl)‐2‐nitro‐4‐(tri­fluoro­methyl)­benzene and 1‐(4‐chloro­phenyl­sulfanyl)‐4‐nitro‐2‐(tri­fluoro­methyl)­benzene

Two chemical isomers of 3‐nitro­benzotrifluoride, namely 1‐(4‐chloro­phenyl­sulfanyl)‐2‐nitro‐4‐(tri­fluoro­methyl)­benzene, C₁₃H₇ClF₃NO₂S, (I), and 1‐(4‐chloro­phenyl­sulfanyl)‐4‐nitro‐2‐(tri­fluoro­methyl)­benzene, C₁₃H₇ClF₃NO₂S, (II), have been prepared and their crystal structures determined with the specific purpose of forming a cocrystal of the two. The two compounds display a similar conformation, with dihedral angles between the benzene rings of 83.1 (1) and 76.2 (1)°, respectively, but (I) packs in P while (II) packs in P2₁/c, with C—H⋯O interactions. No cocrystal could be formed, and it is suggested that the C—H⋯O associations in (II) prevent intermolecular mixing and promote phase separation.     

含油岩心显微荧光成像光谱研究

发展了一种显微荧光光谱成像技术,并将其应用于天然岩心进行显微荧光成像光谱研究。利用这种技术同时采集含油岩心表面的荧光光谱信息和空间信息．并对获得的光谱图像给予光谱学和地质学解释。结果表明,不但能显示岩心形貌和组分的大致趋势,而且能揭示其精细细节．为石油地质研究提供了一种新方法,为今后的石油勘探开发工作提供了一种先进的指导手段。     

4,6‐Di­chloro‐2‐(methyl­thio)­pyrimidine

The structure of the title compound, C₃₀H₂₄Cl₁₂N₁₂S₆, (I), comprises six symmetry unique mol­ecules that vary only slightly in their N—C—S—C torsion angle. All the mol­ecules are planar to within less than 3.1°.     

Preparation and Photophysical Properties of Mixed-Ligand Cyclometallated Complexes of Ir(III) with a Dendritic Bipyridine Ligand

Complexes [Ir(C^N)₂(G1-bpy)]PF₆, where C^N is a cyclometallating ligand derived from 2-(2′-thienyl)pyridine and 2-phenylpyridine, and G1-bpy is a dendritic bipyridine ligand of the first generation, 4,4′-bis[3″,5″-bis(benzyloxy)phenylethyl]-2,2′-bipyridine, were prepared and characterized by ¹H NMR, electronic absorption, and emission spectroscopy. The polyether dendritic substituents exert a “ soft” effect on the spectral and luminescence properties of the complexes, manifested as slight destabilization of the electronically excited charge-transfer state involving the bipyridine ligand, as compared to the model complexes [Ir(C^N)₂(bpy)]PF₆.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 705–711.Original Russian Text Copyright © 2005 by Kulikova, McClenaghan, Balashev.