Characteristic Evaluation of Gas Chromatography with Different Detectors for Accurate Determination of Sulfur Hexafluoride.

Sulfur hexafluoride (SF), which survives in the atmosphere for an extremely long period of time, is the most potent greenhouse gas regulated under the Kyoto Protocol. So, the accurate monitoring of atmospheric SF plays an important role in the study of the control policies for reducing greenhouse gas emissions. The instruments for SF measurement are typically calibrated using certified reference materials.

Disilane-bridged architectures: an emerging class of molecular materials.

Disilanes are organosilicon compounds that contain saturated Si-Si bonds. The structural characteristics of Si-Si single bonds resemble those of C-C single bonds, but their electronic structure is more similar to that of C[double bond, length as m-dash]C double bonds, as Si-Si bonds have a higher HOMO energy level. These organosilicon compounds feature unique intramolecular σ electron delocalization, low ionization potentials, polarizable electronic structure, and σ-π interaction.

Novel organoboron complexes with robust core: Synthesis, functionalization, and subcellular targeting.

The construction of novel organoboron complexes with facile synthesis and unique advantages for biological imaging remains a challenge and thus has garnered considerable attention. Herein, we developed a new molecular platform, boron indolin-3-one-pyrrol (BOIN3OPY) via a two-step sequential reaction. The molecular core is robust enough to allow for post-functionalization to produce versatile dyes.

Si-Bridged annulated BODIPYs: synthesis, unique structure and photophysical properties.

Two novel Si-bridged -annulated BODIPY dyes have been prepared through intermolecular C-I silylation and subsequent intramolecular C-H silylation in a one-pot reaction. A marked redshift of the main spectral bands was observed since the efficient σ*-π* conjugation results in a notable stabilization of the LUMOs. Si-annulation blocks the non-radiative decay and contributes to higher fluorescence quantum yields.

Rationalizing the effect of benzo-fusion at [a] and [b] positions of BODIPY on fluorescence yields.

The origin of the large difference of fluorescence yields between benzo[a] and benzo[b] BODIPY derivatives was investigated. The benzo[a]-BODIPY chromophore shows high fluorescence yields while the totally quenched fluorescence of benzo[b]-BODIPYs is observed. Quantum calculations indicated that larger spin-orbit coupling (SOC) and smaller singlet-triplet energy gaps result in non-fluorescence for benzo[b]-BODIPY.

Nonsymmetric Benzo[]fused and Thiophene/Thieno[3,2-]thiophene[]fused BODIPYs: Synthesis and Photophysical Properties.

The fusion of sufficient-electron heterocycle rings into the[]/[]-position of the BODIPY core would result in a large redshift wavelength, thus achieving red or near infrared emission. In this paper, we described the synthesis of nonsymmetric benzo[]fused and thiophene/thieno[3,2-]thiophene[]fused BODIPY derivatives while containing a reactive site, and then, were developed by nucleophilic substitution reactions of with various nucleophilic agents in high yields. X-ray crystallographic analysis of revealed that the core structure adopted a planar geometry and π-π interactions were observed in the packing structure.

Oligosilanyl-Bridged Biscarbazoles: Structure, Synthesis, and Spectroscopic Properties.

Oligosilanyl-bridged systems are expected to give rise to unique optoelectronic properties because of σ-π conjugation between the Si-Si σ orbital and the aryl π orbital. Herein, we synthesized a small series of novel biscarbazoles bridged with permethylated oligosilanyl units (-[Si(CH)]-, = 1-4) and examined their spectroscopic properties in detail. In the target molecules , = 2-4, the efficient σ-π conjugation elevated the highest occupied molecular orbital energy level with no influence on the lowest unoccupied molecular orbital.

A General Strategy for the Construction of NIR-emitting Si-rhodamines and Their Application for Mitochondrial Temperature Visualization.

Si-rhodamine (SiR) is an ideal fluorophore because it possesses bright emission in the NIR region and can be implemented flexibly in living cells. Currently, several promising approaches for synthesizing SiR are being developed. However, challenges remain in the construction of SiR containing functional groups for bioimaging application.

Real-time monitoring of newly acidified organelles during autophagy enabled by reaction-based BODIPY dyes.

Real-time monitoring of newly acidified organelles during autophagy in living cells is highly desirable for a better understanding of intracellular degradative processes. Herein, we describe a reaction-based boron dipyrromethene (BODIPY) dye containing strongly electron-withdrawing diethyl 2-cyanoacrylate groups at the α-positions. The probe exhibits intense red fluorescence in acidic organelles or the acidified cytosol while exhibiting negligible fluorescence in other regions of the cell.

Lysosome-targeting turn-on red/NIR BODIPY probes for imaging hypoxic cells.

A small series of fluorescent lysosome-targeting probes based on the BODIPY fluorophore and containing morpholine and nitro groups were rationally designed. These probes emitted light from green to NIR wavelengths, and provided specificity for imaging the lysosomes of hypoxic cells. The electron-withdrawing nitrophenyl group at the meso position was found to lead to highly efficient nonradiative decay of the S1 state, and hence a recovery of fluorescence when reduction of the nitro group occurred under hypoxic conditions.

Thieno[3,2-b]thiophene fused BODIPYs: synthesis, near-infrared luminescence and photosensitive properties.

The fusion of π-sufficient heteroaryl moieties has proven to be an effective strategy for achieving the red shift of the main spectral bands of BODIPY. In this paper, thieno[3,2-b]thiophene-fused BODIPY derivatives 1 and 2 have been designed and characterized by various spectroscopic methods, and their photosensitive properties have also been explored. Both dyes absorb in the near-infrared region with extremely high molar extinction coefficients, due to the extension of π-conjugation by fusion of the thieno[3,2-b]thiophene moiety.

A mononuclear five-coordinate Co(ii) single molecule magnet with a spin crossover between the S = 1/2 and 3/2 states.

Although a great number of single-ion magnets (SIMs) and spin-crossover (SCO) compounds have been discovered, multifunctional materials with the combination of SCO and SIM properties are extremely scarce. Here magnetic studies have been carried out for a mononuclear, five-coordinate cobalt(ii) complex [Co(3,4-lut)4Br]Br (1) with square pyramidal geometry. Direct-current magnetic measurement confirms the spin transition between the S = 1/2 and 3/2 states in the range of 150-290 K with a small hysteresis loop.

Naphtho[b]-fused BODIPYs: one pot Suzuki-Miyaura-Knoevenagel synthesis and photophysical properties.

Naphtho[b]-fused BODIPYs have been facilely synthesized via Suzuki-Miyaura-Knoevenagel reaction between mono-iodo-BODIPY or 2,6-diiodo-BODIPY with (2-formylphenyl)boronic acid. This one-pot reaction represents a very straightforward approach for tuning the absorption and emission of BODIPYs in the red visible/NIR range.

Rational Design of Emissive NIR-Absorbing Chromophores: Rh(III) Porphyrin-Aza-BODIPY Conjugates with Orthogonal Metal-Carbon Bonds.

The facile synthesis of Group 9 Rh(III) porphyrin-aza-BODIPY conjugates that are linked through an orthogonal Rh-C(aryl) bond is reported. The conjugates combine the advantages of the near-IR (NIR) absorption and intense fluorescence of aza-BODIPY dyes with the long-lived triplet states of transition metal rhodium porphyrins. Only one emission peak centered at about 720 nm is observed, irrespective of the excitation wavelength, demonstrating that the conjugates act as unique molecules rather than as dyads.

User-friendly aerobic reductive alkylation of iridium(III) porphyrin chloride with potassium hydroxide: scope and mechanism.

Alkylation of iridium 5,10,15,20-tetrakistolylporphyrinato carbonyl chloride, Ir(ttp)Cl(CO) (1), with 1°, 2° alkyl halides was achieved to give (ttp)Ir-alkyls in good yields under air and water compatible conditions by utilizing KOH as the cheap reducing agent. The reaction rate followed the order: RCl < RBr < RI (R = alkyl), and suggests an SN2 pathway by [Ir(I)(ttp)](-). Ir(ttp)-adamantyl was obtained under N2 when 1-bromoadamantane was utilized, which could only undergo bromine atom transfer pathway.

Asymmetric core-expanded aza-BODIPY analogues: facile synthesis and optical properties.

Significantly large Stokes shifts and enhanced solid state emissions were achieved in a novel series of asymmetric core-expanded aza-BODIPY analogues, 4a-4d, synthesized by a facile and scalable two-step reaction in high yields.

Core-modified rubyrins containing dithienylethene moieties.

Two stable core-modified rubyrins bearing one and two dithienylethene (DTE) units (1 and 2) have been synthesized. With one "closed-form" DTE unit, 1 shows aromaticity associated with its conjugated circuit of 26 π-electrons. In contrast, rubyrin 2 containing one "open-form" DTE unit has nonaromatic properties.

Thienopyrrole-expanded BODIPY as a potential NIR photosensitizer for photodynamic therapy.

The synthesis and characterization of a highly photostable bromo-substituted BODIPY dye (I) fused-ring-expanded with thienopyrrole moieties is reported. The results of MTT assays and flow cytometric analyses in living HeLa cells demonstrate that I has a high singlet oxygen quantum yield (ΦΔ = 0.63) and exhibits photocytotoxicity upon irradiation in the NIR region making it potentially suitable for use in PDT.

Enhancing the Stokes' shift of BODIPY dyes via through-bond energy transfer and its application for Fe(3+)-detection in live cell imaging.

Two energy transfer cassettes that exhibit a large pseudo Stokes' shift (up to 400 nm) due to efficient through-bond energy transfer (up to 99%) have been constructed. Selective binding of Fe(III) with the donor entity significantly suppresses the excitation energy transfer resulting in fluorescence quenching in aqueous solution and in living cells.