Starburst triarylamine based dyes for efficient dye-sensitized solar cells

We report here on the synthesis and photophysical/electrochemical properties of a series of novel starburst triarylamine-based organic dyes (S1, S2, S3, and S4) as well as their application in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs). For the four designed dyes, the starburst triarylamine group and the cyanoacetic acid take the role of electron donor and electron acceptor, respectively. It was found that the introduction of starburst triarylamine group to form the D-D-pi-A configuration brought about superior performance over the simple D-pi-A configuration, in terms of bathochromically extended absorption spectra, enhanced molar extinction coefficients and better thermo-stability. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the donor moiety, which was confirmed by electrochemical measurements and theoretical calculations. The DSSCs based on the dye S4 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 13.8 mA cm(-2), an open-circuit photovoltage (V(oc)) of 0.63 V, and a fill factor (ff) of 0.69, corresponding to an overall conversion efficiency of 6.02% under 100 mW cm(-2) irradiation. This work suggests that the dyes based on starburst triphenylamine donor are promising candidates for improvement of the performance of the DSSCs.     

Selective colorimetric and fluorescent detection of HSO4- with sodium(I), magnesium(II) and aluminium(III) xanthone-crown ether complexes

Xanthone-crown ether (1) reacts with NaClO(4), Mg(ClO(4))(2) and Al(ClO(4))(3) forming the one-dimensional chain dinuclear polymer [Na(2).1.(ClO(4))(2)] (2), the mononuclear complex [Mg.1.(H(2)O)(2)](ClO(4))(2) (3) and an interesting sandwich complex [Al.(1)(2).(H(2)O)(6)](ClO(4))(3) (4) with different ratios of metal-to-ligand, respectively. The anion recognition experiment results show that the magnesium complex (3) is a good colorimetric and fluorescent detector for HSO(4)(-) with high sensitivity and selectivity.     

Host–guest‐like thi­amine–anion complexation in thia­minium bis­(tetra­fluoro­borate)

In the title compound, 3‐[(4‐amino‐2‐methyl‐5‐pyrimidin‐1‐io)methyl]‐5‐(2‐hydroxy­ethyl)‐4‐methyl­thia­zolium(2+) bis(tetra­fluoro­borate), C₁₂H₁₈N₄OS²⁺·2BF₄^?, the divalent thia­mine cation (in the F conformation) is associated with BF₄^? anions via two characteristic bridging interactions between the thia­zolium and pyrimidinium rings, i.e. C—H?BF₄^??pyrimidinium and N—H?BF₄^??thia­zolium interactions. Thi­amine mol­ecules are linked by N—H?O hydrogen bonds to form a helical chain structure.     

Spontaneously aggregated chiral nanostructures from achiral tripod-terpyridine

A chiral tripod-terpyridine ligand is known to coordinate with Ag+. These complexes self-assemble into chiral aggregates at room temperature. Molecular dynamic simulation reveals the cooperation of tripodal ligand structures with Ag(I) cations, which leads to the formation of helical aggregations, thus the chirality.     

Liquid chromatographic analysis of nucleosides and their mono-, di- and triphosphates using porous graphitic carbon stationary phase coupled with electrospray mass spectrometry

Analysis of nucleosides and nucleotides is desirable in many biological studies, but the task is analytically challenging due to the high polarity of the analytes. In this study, resolution of mixtures containing nucleosides and their mono-, di- and triphosphates was achieved using a porous graphitic carbon (PGC) stationary phase, Hypercarb, under conditions suitable for liquid chromatography/mass spectrometry (LC/MS). Different organic mobile phases and modifiers were evaluated and the separation of 16 nucleosides and nucleotides was optimized using gradient elution with a water/acetonitrile mobile phase containing ammonium acetate and diethylamine as modifiers. The ammonium acetate concentration proved to be critical for retention and diethylamine was found to improve the peak shapes of di- and triphosphates for mass spectrometric detection. A variety of silica-based columns designed for polar compound separation were also tested using optimized LC conditions and compared with results obtained with the Hypercarb column. Only the Hypercarb column provided separations suitable for accurate quantitation of mixed nucleosides and their phosphates.     

An Improved Method for the Separation and Quantification of Major Phospholipid Classes by LC-ELSD

An improved HPLC procedure for the separation of phospholipids is described. The method described utilizes a solvent mixture of acetonitrile-methanol–water-trifluoroacetic acid (100:25:1.7:2.5, v/v) as the mobile phase, which is more compatible with the pump than mobile phases containing inorganic acids. Separation was by isocratic elution on a Hypersil silica column coupled to an evaporative light scattering detector. Complete separation of phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM) was achieved in less than 20 min. The detection limits for PS, PE, PC and SM were 50, 50, 80 and 150 ng (S/N = 3), respectively. Human, bovine and porcine erythrocyte ghost membranes and animal tissues have been successfully analyzed for their phospholipid contents.     

Dynamical (e,2e) studies of tetrahydrofurfuryl alcohol

Cross section data for electron scattering from DNA are important for modelling radiation damage in biological systems. Triply differential cross sections for the electron impact ionization of the highest occupied outer valence orbital of tetrahydrofurfuryl alcohol, which can be considered as an analogue to the deoxyribose backbone molecule in DNA, have been measured using the (e,2e) technique. The measurements have been performed with coplanar asymmetric kinematics at an incident electron energy of 250 eV, an ejected electron energy of 20 eV, and at scattered electron angles of -5°, -10°, and -15°. Experimental results are compared with corresponding theoretical calculations performed using the molecular 3-body distorted wave model. Some important differences are observed between the experiment and calculations.     

Ring-opening polymerisation of ɛ-caprolactone catalysed by Brønsted acids

Two new Brønsted acids [2,2′-ethylidene-bis (4,6-di-tert-butylphenol)] phosphoric acid (EDBPPOOH) and (3,3′,5,5′-tetra-tert-butylbiphenyl-2,2′-diol) phosphoric acid (TBPO-POOH) were synthesised and fully characterised by ¹H NMR and ¹³C NMR spectra and mass spectra. The ringopening polymerisation (ROP) of ?-caprolactone (?-CL) catalysed by the two Brønsted acids proceeded at 110°C without a solvent or at ambient temperature in toluene. Experimental results indicated that the two Brønsted acids were efficient catalysts for the ROP of ?-CL with moderate number-average molar mass (Mn) and narrow polydispersity indices (PDI). The catalytic activity of TBPO-POOH is higher than EDBP-POOH in the ROP of ?-CL. After benzyl alcohol was added, it was able to accelerate the polymerisation process. The polymerisation can also occur with the addition of water with a monomer/catalyst/initiator mole ratio of 100: 1: 1. The living polymerisation was ascertained by the linear relationships of the Mn vs. monomer conversion, then it was further confirmed by a second-feed experiment of a double monomer producing double Mn. A kinetic study of the relationships between monomer concentration and time revealed a first-order dependence on monomer concentration in the polymerisation. End-group analysis of ¹H NMR spectra and electrospray-ionisation mass spectra suggests that the two Brønsted acids are capable of catalysing and initiating the ROP of ?-CL.     

Precisely Controlled Delivery of Abaloparatide through Injectable Hydrogel to Promote Bone Regeneration

Side‐effects from allograft, limited bone stock, and site morbidity from autograft are the major challenges to traditional bone defect treatments. With the advance of tissue engineering, hydrogel injection therapy is introduced as an alternative treatment. Therapeutic drugs and growth factors can be carried by hydrogels and delivered to patients. Abaloparatide, as an analog of human recombinant parathyroid hormone protein (PTHrp) and an alternative to teriparatide, has been considered as a drug for treating postmenopausal osteoporosis since 2017. Since only limited cases of receiving abaloparatide with polymeric scaffolds have been reported, the effects of abaloparatide on pre‐osteoblast MC3T3‐E1 are investigated in this study. It is found that in vitro abaloparatide treatment can promote pre‐osteoblast MC3T3‐E1 cells’ viability, differentiation, and mineralization significantly. For the drug delivery system, 3D porous structure of the methacrylated gelatin (GelMA) hydrogel is found effective for prolonging the release of abaloparatide (more than 10 days). Therefore, injectable photo‐crosslinked GelMA hydrogel is used in this study to prolong the release of abaloparatide and to promote healing of defected bones in rats. Overall, data collected in this study show no contradiction and imply that Abaloparatide‐loaded GelMA hydrogel is effective in stimulating bone regeneration.     

Making JP‐10 Superfuel Affordable with a Lignocellulosic Platform Compound

The synthesis of renewable jet fuel from lignocellulosic platform compounds has drawn a lot of attention in recent years. So far, most work has concentrated on the production of conventional jet fuels. JP‐10 is an advanced jet fuel currently obtained from fossil energy. Due to its excellent properties, JP‐10 has been widely used in military aircraft. However, the high price and low availability limit its application in civil aviation. Here, we report a new strategy for the synthesis of bio‐JP‐10 fuel from furfuryl alcohol that is produced on an industrial scale from agricultural and forestry residues. Under the optimized conditions, bio‐JP‐10 fuel was produced with high overall carbon yields (≈65 %). A preliminary economic analysis indicates that the price of bio‐JP‐10 fuel can be greatly decreased from ≈7091 US$/ton (by fossil route) to less than 5600 US$/ton using our new strategy. This work makes the practical application of bio‐JP‐10 fuel forseeable.