Syntheses,Crystal Structures and Fluorescence Properties of Two Mononuclear Copper(Ⅱ) Compounds

Two new compounds,1（[Cu（IDB_）2]Cl_2·2CH_3CH_2OH·2H_2O（IDB = N,N-di（2-benzimidazolylmethyl）imine]） and 2（[Cu（EDTB）]·2[C_6H_4（OH）COO]·6H_2O（EDTB = N,N,N＇,N＇-tetrakis-[（2-benzimidazolyl）methyl]-1,2-ethanediamine]）,have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system,space group P1 with a = 9.565（2）,b = 9.863（2）,c = 10.252（3） ？,α = 81.915,β = 88.330,γ = 87.347°,V = 956.28（40） ？3,Z = 1,F（000） = 427,D_c = 1.419 g/cm3,Mr = 817.27 and μ（MoKα） = 0.764 mm^（-1）. The final R indices（I 〉 2σ（I））： R = 0.0505,wR = 0.1417; R indices（all data）： R = 0.0591,wR = 0.1525. Crystal 2 is of triclinic system,space group P1 with a = 11.487（3）,b = 13.396（4）,c = 17.977（5） ？,α = 73.899（5）,β = 86.629（5）,γ = 65.018（4）°,V = 2403.8（12） ？3,Z = 2,F（000） = 1072,D3c = 1.417 g/cm,Mr = 1025.54,μ（MoKα） = 0.528 mm^（-1）. The final R indices（I 〉 2σ（I））： R = 0.0769,w R = 0.163 2; R indices（all data）： R = 0.0769,wR = 0.1632. The two compounds exhibit mononuclear structures. The copper（Ⅱ） atom of crystal 1 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand IDB to adopt a distorted octahedral coordination geometry. The copper（Ⅱ） atom of crystal 2 is six-coordinated by four nitrogen atoms of benzimidazole groups and two amine nitrogen atoms from the ligand EDTB to show a distorted octahedral coordination geometry. Particularly,the two compounds exhibit fluorescent properties at room temperature in ethanol.

Synthesis,Crystal Structure and Luminescence Study of a New Two-dimensional Mn(Ⅱ)Coordination Polymer

The coordination polymer [Mn2（cipt）2（aic）2]n （cipt = 2-（3-chlorophenyl）-1H- imidazo[4,5-f][1,10]phenanthroline, aic = 5-amino-isophthalic acid） has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The title compound crystallizes in the triclinic system, space group P , with a = 11.523（3）, b = 12.162（3）, c = 18.706（5） A^°, β = 81.789（5）°, V = 2455.2（1） A^°3, C54H32Cl2Mn2N10O8, Mr = 1129.68, Z = 2, Dc = 1.528 g/cm3, μ = 0.692 mm^-1, F（000） = 1148, R = 0.064 and wR = 0.145 for 9571 observed reflections （I 〉 2σ（I））. In this polymer, the Mn（II） atoms adopt different coordination modes. The Mn（1） atom is five-coordinated, forming a distorted tetragonal pyramidal geometry. Mn（2） atom is six-coordinated to get a distorted octahedral geometry, which is different from the Mn（1） atom. Each Mn（II） atom is linked by aic ligands with neighboring Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. The existence of N–H…O hydrogen bonding interactions leads the 1D chains to generate a 2D structure. Luminescent properties for the ligand cipt and compound 1 have also been discussed in detail.

Applying a fish expert system for ranking the biological effects of polycyclic aromatic hydrocarbons on the rockfish Sebastiscus marmoratus in the Maowei Sea,China

Polycyclic aromatic hydrocarbons(PAHs)pollution,particularly in coastal environments,is a global concern.In this study,the biomonitoring and ranking effects of PAHs in the rockfish Sebastiscus marmoratus were determined in the Maowei Sea,China.The results showed that the concentrations of the 16 priority PAHs detected in the surface seawater were moderate compared with those in other coastal areas worldwide,and the possible sources were rapid industrialization and urbanization combined with atmospheric deposition and runoff.Nested analysis of variance(ANOVA)suggested significant differences in the hepatic ethoxyresorufin-O-deethylase(EROD)activities and phenanthrene-derived metabolites in bile between the port area and the oyster farming area.The fish expert system(FES)was applied to evaluate the biological effects of PAHs on fish.The FES data demonstrated that the biological effect levels of Site S1(level III,medium stress)were higher than those of the other sampling sites(level II,low stress).

Two Low-temperature Phase Transition Compounds Based on Quinuclidine Derivatives with Fluorescence

Two phase transition materials[iPrQ]2MnBr4(1,iPrQ=N-isopropyl-quinuclidinium)and[iPrQ]_(2)MnCl_(4)(2)were synthesized and characterized.Dielectric measurements and differential scanning calorimetry showed that the two compounds underwent reversible phase transitions at ca.–47 and–37℃,respectively.Variable-temperature single-crystal X-ray diffraction suggested that the two compounds underwent the same phase transitions from space group C2/c to Cc but at different temperature.The variable crystal structures indicated that the structural phase transitions of the compound were ascribed to the torsional movement of quinuclidine ring and the disappearance of the c-slide plane.The second harmonic generation(SHG)response further proved this structural phase transition.Fluorescence tests showed that the two compounds have strong fluorescence.The strong variations in dielectric anomalies make compounds 1 and 2 suitable for promising switchable dielectric materials.

Crop plant signaling for real-time plant identification in smart farm: A systematic review and new concept in artificial intelligence for automated weed control

The continued emergence of herbicide-resistant weeds and the increasing labor costs are threatening the ability of growers to manage weeds and maintain profits.The smart farm with the advantage of non-invasive and high-efficiency operation plays an important role in increasing the sustainability of agricultural system as it can optimize crop inputs such as herbicides while preserving resources including soil and water.An automatic weed control system requires a sensing subsystem capable of detecting and distinguishing crop plants from weeds.The overlapping plants remain a challenge for successful detection of weeds.Crop plant signaling is a new robot-plant interaction technique that allows the visualization of exogenous fluorescent signals applied to crop plants for crop/weed identification.Based on all published articles in the leading edge of knowledge,a comprehensive review of the mushrooming crop plant signaling for discriminations of weeds and crops is highlighted.The discussion outlines the significant progress that has been made in developing new and more robust automated systems along with the current challenges and future prospects.This paper details the promise of crop plant signaling for accurate and automated plant recognitions in cropping systems.There is no doubt that this review is of great significance to scholars in related research field to study the solutions to real-time weed control.

Colorimetric and fluorimetric detection of cysteine: Unexpected Michael addition–elimination reaction

The synthesis of three isomers based on Michael addition mechanism for the detection of sulfurcontaining species in aqueous solution is described. These compounds are constructed by conjugating an enone to a coumarin fluorophore. A substituted-phenyl（o, m, or p-） was appended at the carbonyl carbon to adjust the reactivity. The experimental results showed that（E）-7-（diethylamino）-3-（3-（3-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（m-QPS） and（E）-7-（diethylamino）-3-（3-（4-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（p-QPS） barely react with sulfur-containing nucleophiles, while（E）-7-（diethylamino）-3-（3-（2-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（o-QPS） exhibited a fast response toward sulfite, sulfide and thiols in DMSO/phosphate buffer（2：1）. The above results are probably due to the intramolecular H-bonding activated Michael addition.More interestingly, cysteine triggered unusual photophysical responses of o-QPS： the original absorption（488 nm） and emission peaks（573 nm） underwent significant blue shifts initially and then recovered,which might be caused by the Michael addition and elimination reaction, respectively.