Pedogenic Carbonate and Soil Dehydrogenase Activity in Response to Soil Organic Matter in Artemisia ordosica Community

Little attention has been paid to the role of soil organic matter (OM) in the formation of pedogenic carbonate in desert soils.The relationships among soil OM,soil dehydrogenase activity (DHA),and soil CaCO 3 in a plant community dominated by Artemisia ordosica,located on the eastern boundary of Tengger Desert in the Alxa League,Inner Mongolia,China,were studied to understand whether OM was directly involved in the formation of pedogenic carbonate.The results showed that DHA and CaCO 3 positively correlated with OM content,and DHA,OM,and CaCO 3 were correlated with each other in their spatial distribution,indicating that abundant OM content contributed to the formation of CaCO 3.Therefore,the formation of pedogenic CaCO 3 was a biotic process in the plant community dominated by A.ordosica.

Synthesis and Crystal Structure of 2(1-Phenyl-3-methyl-5-chloro-1H-pyrazol- 4-yl)-3-(1-naphthoylamido)-4-thiazolidinone

The crystal structure of 2(1-phenyl-3-methyl-5-chloro-1H-pyrazol-4-yl)-3-(1- naphthoylamido)-4-thiazolidinone (C24H19ClN4O2S, Mr = 462.94) has been determined by single- crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 11.623(5), b = 11.579(5), c = 16.619(7) ? b = 90.112(8), V = 2237(2) 3, Z = 4, Dc = 1.375 g/cm3, m = 0.294 mm-1, F(000) = 960, R = 0.0492 and wR = 0.0768 for 3932 unique reflections with 1897 observed ones (I > 2s(I)). X-ray analysis reveals that there exist both intra-and intermolecular hydrogen bonds in the crystal lattice.

Synthesis and Herbicidal Activity of Novel 5-Substituted Benzenesulfonylureas

Sulfonylurea herbicides have been widely used because of their low application rates, good crop sdeetivities and low mammalian toxicities. However, some sulfonylureas might persist unfavourably in the environment with residual problems. In order to look for ecologically safer and environmentally benign sulfonylureas, and on keeping the pyrimidine ring being monosubstitated, 15 novd C5-monosubstituted benzenesulfonylurea compounds were synthesized. The structures of all the compounds synthesized were confirmed by demental analysis and ^1H NMR. Preliminary herbicidal activities of these new sulfonylurea compounds were determined by ALS screening （ in vitro） and pot bioassay experiments（ in vivo）. The herbicidal results show that some novel sulfonylureas are comparable to commercial Foramsulfuron and Monosulfuron.

Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Thiadiazol Moiety

Thirteen novel sulfonylureas containing thiadiazole moiety were synthesized in a two-step reaction. Their structures were determined using IR, ^1H NMR, HRFTMS, and elemental analysis. Herbicidal activities of these compounds were determined in the green house bio-assay. The results show that four compounds among them exhibit some activity toward four tested herbs.

Binding of Pyrene to Different Molecular Weight Fractions of Dissolved Organic Matter:Effects of Chemical Composition and Steric Conformation

The binding constant（KDOM） of pyrene onto different molecular weight（Mw） fractions of a dissolved organic matter（DOM） extract from an estuarine sediment was measured via a fluorescence quenching method,and the possible binding mechanisms were discussed.The influence of water chemical parameters on pyrene binding was studied to elucidate the effects of DOM steric conformation.DOM fraction with larger M w（14000） showed a greater KDOM（2.02×10 5） than that with smaller Mw did,and the KDOMs were 1.16×105 and 1.13×105 for the fractions with M w of 1000―14000 and 1000,respectively.The K DOM s of different M w DOM fractions were correlated positively with the atomic ratio of C/H and absorbance at 280 nm;while a negative correlation existed between K DOM and（O＋C）/N（atomic ratio）,and K DOM and O-containing groups.These correlations indicate the positive influence of aromatic structure and the negative effect of polarity on DOM binding capacity.Infrared spectroscopy revealed that specific interactions existed between pyrene and the DOM fraction with larger M W besides hydrophobic partition,i.e.,NH-π interaction in DOM moiety（1000―14000） and π-π electron donor acceptor（EDA） forces in DOM moiety（14000）.KDOM varied in a complex pattern with increasing cation concentration and pH,which could be explained by the change in DOM steric conformation.Formed aggregates favored the lipophilic partition of pyrene.However,the accessibility to some interior binding sites became low when the aggregate was too large,leading to a reduced KDOM.

Design,Synthesis and Insecticidal Activities of Novel Phenyl Substituted Isoxazolecarboxamides

Thirteen novel phenyl substituted isoxazolecarboxamides were synthesized, and their structures were characterized by IH NMR, elementary analysis and high-resolution mass spectrometry（HRMS） techniques. Their evaluated insecticidal activities against oriental armyworm（Mythimna separata） indicate that the phenyl substituted isoxazolecarboxamides exhibited moderate insecticidal activities, among which compounds 9c and 9k showed com- paratively higher activities.

Synthesis and Herbicidal Activity of Novel Sulfonylurea Derivatives

Sulfonylurea herbicides have been applied worldwide in agriculture. Some sulfonylurea residues might exist in soil longer than that people expected. However, flupyrsulfuron-methyl-sodium which was firstly reported as a new 5-substituted sulfonylurea herbicide has less than one month residual life. Therefore, 5-substituted benzenesulfonylureas are potential molecules to regulate its residual situation. In order to develop new sulfonylurea derivatives, the substituent on the critical 5-posotion of the benzene ring was optimized. On the basis of our former work on sulfonylureas which contains a characteristic mono-substituted pyrimidine moiety, twenty-six new sulfonylurea deriva- tives were synthesized and their structures were confirmed by 1H NMR, 31p NMR and elemental analysis. The greenhouse bioassay tests show that some title compounds exhibit potent herbicidal activity.

Polyethylene glycol radical-initiated aerobic propargylic oxidation in dense carbon dioxide

The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG 1000 under 5 MPa of CO2 and 2 MPa of O2 at 100 ℃ for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.

Synthesis and herbicidal activities of pyridyl sulfonylureas:More convenient preparation process of phenyl pyrimidylcarbamates

四 4-monosubstituted 嘧啶 pyridyl sulfonylureas 从 pyridinesulfonamide 和苯基 pyrimidylcarbamate 被综合并且为 herbicidal 屏蔽了活动。我们也从 pyrimidineamine 和苯基 chloroformate 报导了苯基 pyrimidylcarbamates 的一个方便准备过程。

A New Diterpenoid from Hydroclathrus tenuis

A new dolabellane diterpene 1, named as hydroclathrol, has been isolated from the alga Hydroclathrus tenuis. Its structure has been determined on the basis of spectral analysis as 1, 4, 8-trimethyl-14-isopropyl-bicyclo [9, 3, 0]-4(Z), 8(E), 11(Z)-tetradeca triene-6-ol.

Synthesis and Crystal Structure of 1-[（1＇-Phenyl-5＇-methyl-4＇-pyrazolcarbonyl）-3-methylthio-5-amino-1Hy l-1,2,4-triazole

The crystal structure of 1-[(1?-phenyl-5?-methyl-4?-pyrazolcarbonyl)]-3-methyl thio- 5-amino-1H-yl-1,2,4-triazole (C14H14N6OS, Mr = 314.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to triclinic, space group P1 with a = 8.026(3), b = 8.651(4), c = 11.369(5) ?, α = 89.917(7), β = 89.084(7), γ = 68.470(6)°, V = 734.2(5) ?3, Z = 2, Dc= 1.422 g/cm3, μ = 0.232 mm-1, F(000) = 328, R = 0.0376 and wR = 0.0890 for 2950 unique reflections. The crystal structure shows the presence of a dimmer with intermolecular N(4)–H(4)… N(3A) hydrogen bonds.

One-dimensional Inclusion Polymers of Calix[4]arene Monomethoxycarboxylic Acid

X-ray crystal structures of the inclusion complexes of calix[4]arene monomethoxycarboxylic acid 1 （C30H2606） with acetontrile and acetone are reported. The crystal of C30H26O6·CH3CN is of monoclinic, space group P2 1/c with a = 11.691（5）, b = 13.753（5）, c = 17.072（7）A, β = 100.104（7）°, C32H29NO6, Mr = 523.56, V = 2702.4（18）A^3, Z = 4, De= 1.287 g/cm^3, μ（MoKα） = 0.089 mm^-1, T = 293（2） K, 5570 independent reflections with 3220 observed ones （1 〉 2σ（I））, R = 0.0521 and wR = 0.1132 with GOF = 1.042 （R = 0.1055 and wR = 0.1350 for all data）. The data for C30H26O6·CH3COCH3： monoclinic, space group P2 1/c, α = 12.366（4）, b = 12.119（4）, c = 18.796（6） A, β = 90.871（6）°, C33H32O7, Mr = 540.59, V = 2816.6（16）A^3, Z = 4, Dc = 1.275 g/cm^3, μ（MoKα） = 0.089 mm^-1, T = 293（2） K, 5783 independent reflections including 2580 observed ones （I 〉 2σ（I））, R = 0.0555 and wR = 0.1424 with GOF= 0.975 （R = 0.1601 and wR = 0.1884 for all data）. Their architectures exhibit one-dimensional inclusion polymers which are mediated head-to-tail by the guests.

Two Brominated-sesquiterpene from Alga Laurencia Majuscula

Two brominated sesquiterpenes were isolated from the Alga Laurencia majuscula collected from the Xisha Islands in the South China Sea. Compound 1 was first reported, and determined, on spectral evidence, to be 8 bromo 1 en chamigrene.

Synthesis and Crystal Structure of Novel Sn-O Clusters Generated from ~nBu_2SnO and Esters

A facile and credible strategy was demonstrated to synthesize two new Sn-O clusters 1 and 2 by the reactions of nBu2SnO with esters directly under mild conditions.Cluster 1 crystallizes in the triclinic system,space group P1 with a = 13.054（3）,b = 13.137（3）,c = 15.077（3） ,α = 80.009（9）,β = 77.187（10）,γ = 76.075（11）°,Z = 2,V = 2427.3（9） 3,Dc = 1.565 g/cm3,μ（MoKα） = 2.076 mm-1,F（000） = 1152,the final R = 0.0335 and wR = 0.0664 for 9416 observed reflections（I 2σ（I））.Cluster 2 belongs to the monoclinic system,space group P21/c with a = 13.673（3）,b = 13.342（3）,c = 16.296（4） ,β = 104.385（5）o,Z = 4,V = 2879.7（10） 3,Dc = 1.347 g/cm3,μ（MoKα） = 1.751 mm-1,F（000） = 1176,the final R = 0.0306 and wR = 0.0706 for 6390 observed reflections（I 2σ（I））.The crystal structures of the clusters consist of cen-trosymmetric [RCOOSnnBu2OSnnBu2OH）]2 molecules with an almost planar Sn4O4 framework.Each pair of exo-and endo-cyclic tin atoms was linked by one bridge-OH only.In addition,a novel structure of nBu2SnO different from the previous reports was proposed on the basis of 1H-NMR,TG analysis and X-ray diffraction.

THE REACTION OF SUBSTITUTED PHENOXY ACETYL CHLORIDE WITH TRIMETHYL PHOSPHITE

Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by ~1HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.

No-solvent Condensation Reaction of Amino Acids and their Derivatives with Pyrandione

Synthesis of a novel series of N-pyrandione substituted amino acids and their esters 3 via a condensation reaction between pyrandione and amino acid or their derivatives in excess ethyl orthoformate without solvent is described. The stereochemistry of 3 has been discussed.

Facile Synthesis of Five-membered Phosphoroheterocycles Bearing N-P-N and S-P-N Moieties

New reactions of Lawesson reagent (LR) with alpha -hydroxy (amino)nitriles have been studied. The experimental results showed that the five-membered phosphoroheterocycles 2 and 4 bearing N-P-N or S-P-N moiety could be readily prepared in high yields. Meanwhile, the possible mechanism of the reactions was also discussed.