Landscape of s-triazine molecule on Si(100) by a theoretical x-ray photoelectron spectroscopy and x-ray absorption near-edge structure spectra study

The chemisorbed structure for an aromatic molecule on a silicon surface plays an important part in promoting the development of organic semiconductor material science. The carbon K-shell x-ray photoelectron spectroscopy（XPS） and the x-ray absorption near-edge structure（XANES） spectra of the interfacial structure of an s-triazine molecule adsorbed on Si（100） surface have been performed by the first principles, and the landscape of the s-triazine molecule on Si（100） surface has been described in detail. Both the XPS and XANES spectra have shown their dependence on different structures for the pristine s-triazine molecule and its several possible adsorbed configurations. By comparison with the XPS spectra, the XANES spectra display the strongest structural dependency of all of the studied systems and thus could be well applied to identify the chemisorbed s-triazine derivatives. The exploration of spectral components originated from non-equivalent carbons in disparate local environments has also been implemented for both the XPS and XANES spectra of s-triazine adsorbed configurations.

Large second-order optical nonlinearities of s-triazine derivatives: View from micro molecules to macro crystals

Three s-triazine derivatives have been synthesized and their structures been de-termined. These are Compound I: 2,4-dimethyl-6-(p-N,N-dimethylaminostyryl)-s-triazine (abbre-viated to NMe-1), Compound II: 2,4-dimethyl-6-(p-N,N-diethylaminostyryl)-s-triazine (to NEt-1), and Compound III: 2-methyl-4,6-bis(p-N,N-dimethylaminostyryl)-s-triazine (NMe-2). NMe-1 and NEt-1 molecules belong to the D-π-A type with a one-dimensional charge-transfer character. NMe-1 crystallizes to centrosymmetric P1 space group, while NEt-1 to non-centrosymmetric polar Cc space group with all of the molecular charge-transfer axes taking the same orientation. Under the irradiation of 1064 nm fundamental laser, NEt-1 powder crystals radiate a 2-order harmonic light with an intensity 46.8 times that of urea. The Λ typed NMe-2 molecule, which has a two-dimensional charge-transfer character, crystallizes to polar P21 space group. Its powder crystals exhibit a 2-order harmonic intensity 46.2 times that of urea. The quantum chemical cal-culations and tensor analyses have been carried out to reveal the dependence of the macro 2-order nonlinear optical (NLO) efficiency on the micro 2-order NLO coefficients (β) and on the crystalline packing styles.

Molecular engineering of s-triazine and its derivatives applied in surface modification strategy for enhancing photoelectric performanc of all-inorganic perovskites

We develop the effective modification strategy based on molecular engineering of s-triazine and its derivatives to improve the photoelectric performance of all-inorganic perovskites(AIP)for the first time.The surface modification strategy with cyanuric acid successfully increases the PLQY of AIP from 40.55%to 88.15%,and significantly enhances the current of the AIP film under 3 V by almost 20-fold(from4.44 m A to 81.20 m A).This work has proven the effectiveness of improving the photoelectric performances of AIP via s-triazine and its derivatives and also suggested the potential risks of reducing the photoelectric performance of AIP due to inappropriate substituents in conjugated organic ligands.

Synthesis and Biological Activities of Novel s-Triazine Bridged Dinucleoside Analogs

A series of novel dinucleosides linked by s-triazine were synthesized via the nucleophilic substitution reaction of amino nucleoside and cyanuric chloride in THF/H20. The biological activities of these novel dinucleoside analogs against HIV-RT, HeLa and A-549 cell lines in vitro were evaluated.

Sorption of four s-triazine herbicides on natural zeolite and clay mineral materials with microporosity

Sorption is an important process that controls the fate and transport of herbicides in the soil and aquifer environment.However,sorption of these pollutants on natural microporous mineral materials has received little attention.This study investigated the sorption of four model s-triazine herbicides,namely,atrazine,metribuzin,ametryn,and prometryn,on two common natural zeolites(i.e.,clinoptilite and Fe-mordenite)and two common clays(i.e.,kaolin and attapulgite)with microporosity in batch experiments.The results showed that the sorption of s-triazines on the natural zeolites increased in the order of metribuzin<atrazine<ametryn<prometryn,which corresponded approximately to the order of increasing sorbate hydrophobicity and indicated the significant contribution of the hydrophobic effect.In contrast,the sorption of s-triazines on the natural clays increased in the order of metribuzin<atrazine<prometryn<ametryn,which corresponded to the order of increasing sorbate basicity and indicated the significant contribution of cation exchange and electrostatic interactions.The sorption of these s-triazines on the mineral materials was strongly pH-dependent,resulting from the pH dependence of the mineral surface charge and protonation/deprotonation of the s-triazines.Common alkali and alkaline earth cations at low concentrations had no significant impact on the sorption of s-triazines on the natural microporous mineral materials.Meanwhile,the presence of Fe^(3+)(at 0.05 mmol/L)significantly enhanced the sorption of atrazine,ametryn,and prometryn by increasing the protonation of s-triazine molecules in the interfacial region between the mineral surface and bulk solution(due to hydrolysis of Fe^(3+)).Co-sorption of s-triazines on the natural microporous mineral materials exhibited significant competitive effects when these herbicides are sorbed through similar mechanisms.The findings of this study provide insights on the interactions of s-triazine herbicides with natural microporous mineral materials,which help better understand and predict their occurrence and behavior in the subsurface.

Synthesis and Fluorescence of Tb^(3+) and Eu^(3+) Complexes with N, N', N

Tb￣(3+) and Eu￣(3+) complexes of N, N ', N'-1, 3, 5-triazine-2, 4, 6-triyltris-[N- (carboxymethyl)]-glycine were synthesized and characterized by elemental analysis, TG-DTA, UV,IR, fluorescence and phosphorescence spectroseopy. It was shown that the ligand can sensitize the fluorescence of Tb￣(3+) but not sensitize the luminescence of Eu￣(3+). The mechanism of luminescence was discussed based upon the phosphorescence of the ligand.

Investigations on the Degradation of Triazine Herbicides in Water by Photo-Fenton Process

In this work, the degradation of 2-chloro-4,6-diamino-1,3,5-triazine in aqueous solutions by photo-Fenton process has been investigated. The preliminary results have shown that the degradation of 2-chloro-4,6-diamino-1,3,5-triazine by photo-Fenton process is more rapid and more effective than Fenton and UV/H2O2 processes. The effects of certain experimental parameters on kinetics and efficiency of the degradation of 2-chloro-4,6,-diamino-1,3,5-triazine by photo-Fenton process, have been evaluated. Under optimal conditions, photo-Fenton process achieved more than 90% of chloride release and about 30% of nitrate formation. The results of total organic carbon (TOC) and total Kjeldahl nitrogen (TKN) analyses have shown that no carbon dioxide and ammonia are formed during photo-Fenton treatment of aqueous solutions containing 40 mg/L triazine. These results indicate that only substituent groups of triazine ring are released;however, nitrogen atoms of triazine ring remain unaffected. A simple mechanism of degradation of 2-chloro-4,6-diamino-1,3,5-triazine has been proposed. The degradation starts by a rapid release of chlorine atoms as chloride ions to form 2-hydroxy-4,6-diamino-1,3,5-triazine. The amino groups of 2-hydroxy-4,6-diamino-1,3,5-triazine undergo are oxidized into nitro groups by hydroxyl radicals to form 2-hydroxy-4,6-dinitro-1,3,5-triazine which undergoes a slow release of nitro groups and their substitution with hydroxyl groups to form cyanuric acid and nitrate ions. The degradation of cyanuric acid by photo-Fenton process has also been investigated. The results of TOC and TKN analyzes show that no carbon dioxide is formed during the treatment.