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1.
The ingestion of Solanum glaucophyllum ( SG) causes a calcinosis of cattle named Enteque Seco (ES). The toxic principle is the 1,25-(OH) 2D 3, mainly conjugated as glycoside. This study aims to validate a simple novel method of evaluation of the VDA of SG leaves. Aqueous extracts of SG were purified using C 18 minicolumns and assayed by RIA with an antibody raised in rabbits by injection of the acid—C22, 1-(OH)Vitamin D 3. Data were expresed as glycoside equivalent to 1,25-(OH) 2D 3 in ng/g of dry leaves. We compared this data with 1,25-(OH) 2D 3 levels measured, in the same samples, by liquid chromatography (HPLC) after enzyme cleavage. This procedure involved the incubation of SG leaves with rumen fluid, followed by C 18-OH solid phase extraction. The 1,25-(OH) 2D 3 fraction was run by HPLC and detection was achieved using a photodiode array detector. Data were expressed as micrograms of 1,25-(OH) 2D 3/g dry leaves. A significant regression of 1,25-(OH) 2D 3 levels ( Y) as a function of glycoside RIA 1,25-(OH) 2D 3 equivalents ( X) was found: Y = 12.02 + 0.35 X [ R = 0.81; P = 0,0002; N = 15], allowing us to conclude that this novel assay could be used to estimate the amount of this active principle contained in SG leaves. 相似文献
2.
为了研究鮸的形态性状与体质量之间的关系,测量了524尾12月龄左右鮸的体质量( Y, g)和8个形态性状(cm),包括全长( X1)、体长( X2)、头长( X3)、躯干长( X4)、尾长( X5)、尾柄长( X6)、尾柄高( X7)和体高( X8).采用相关分析、回归分析、通径分析以及模型拟合等方法对其进行分析.结果表明: 鮸所有性状两两之间存在极显著正相关关系,相关系数在0.834~0.941.经共线性诊断排除了体长这一具有严重共线性的性状后,采用逐步引入-剔除法进行多元回归并进行显著性检验,成功筛选出全长( X1)、躯干长( X4)、尾柄高( X7)和体高( X8)4个统计检验极显著的形态性状,并建立多元回归方程: Y =-444.188 +7.943 X1 +12.861 X4 +38.254 X7 + 42.722 X8.通径分析结果显示,4个形态性状中,体高对体质量的直接作用最大(通径系数=0.351),全长次之(通径系数=0.335).对全长和体高与体质量之间的函数关系进行曲线模型拟合得出,在6个拟合模型中,幂函数模型拟合效果最好,方程为: y=0.013 x2.891(全长); y=2.028 x2.751(体高).经适合性检验得知,全长比体高通过幂函数对体质量的预测效果更好.研究结果可为鮸的形态性状在选择育种中的有效利用提供重要参考. 相似文献
3.
控制水温在(20±0.5)℃条件下,采用Winkler法和奈氏试剂法分别测定水中的溶氧含量和氨氮含量,通过比较流水呼吸室进、出口水中的溶解氧和氨氮含量之差以确定多鳞四须鲃( Barbodes schwanenfeldi)的耗氧率、排氨率及窒息点.结果表明,多鳞四须鲃耗氧率随体重增加而减小,关系式为 Y=0.24 X-0.09( R2=0.9028);随放养密度的增大而减小,关系式为 Y=-0.029 X+0.3301 ( R2=0.9291).排氨率随体重的增加而减小,关系式为 Y=-0.0008 X+0.2433 ( R2=0.9817);随放养密度的增大而增加,关系式为 Y=-0.050 X+0.4979 ( R2=0.9889).多鳞四须隹巴晚间(18:00~4:00)的耗氧率明显高于白天(6:00-1:00),排氨率则相反,白天的排氨率相对较高,表明多鳞四须鲃巴属于"昼伏夜出"型鱼类.多鳞四须啬巴的窒息点为1.2572mg·L -1,耐氧性较差. 相似文献
4.
铝毒是限制酸性土壤中作物产量的主要因素之一。番茄( Solanum lycopersicum)是适合在酸性土壤中种植的主要经济作物, 不同品种番茄对铝胁迫的响应存在差异, 因此, 筛选苗期耐铝毒种质对番茄生产及研究具有重要意义。以10个番茄品种为材料, 采用室内土培盆栽, 设置1 000 µmol∙L -1 AlCl 3·6H 2O处理, 测定反映植物铝胁迫下生长状况的16个形态、生理生化及光合指标。通过主成分分析, 将铝胁迫下番茄幼苗的16个指标转化为5个独立的综合指标, 累积贡献率达90.779%。基于耐铝性综合评价值( A)的系统聚类分析, 将供试种质划分为5类, 第I类为高度耐铝品种Qianxi, 第V类为高度不耐铝品种Puluowangsi。经多元线性逐步回归分析得出番茄苗期耐铝评价方程: y=0.046+0.405 X6+0.515 X10-0.207 X15+0.028 X3 ( R2=0.997), 从16个指标中提取出与 A值显著相关 (P<0.01)的4个指标: 丙二醛含量( X3)、净光合速率( X6)、叶面积( X10)和地下部干重( X15)。利用评价方程可判断不同番茄品种苗期的耐铝性, 使番茄耐铝性鉴定工作快速简便。 相似文献
5.
Treatment of the A-ring aromatic steroids estrone 3-methyl ether and β-estradiol 3, 17-dimethyl ether with Mn(CO) 5+BF 4− in CH 2Cl 2 yields the corresponding [(steroid)Mn(CO) 3]BF 4 salts 1 and 2 as mixtures of and β isomers. The X-ray structure of [(estrone 3-methyl ether)Mn(CO) 3]BF 4 · CH 2Cl 2 (1) having the Mn(CO) 3 moiety on the side of the steroid is reported: space group P2 1 with a=10.3958(9), b=10.9020(6), c=12.6848(9) Å, β=111.857(6)°, Z=2, V=1334.3(2) Å 3, calc=.481 cm −3, R=0.0508, and wR=0.0635. The molecule has the traditional ‘piano stool’ structure with a planar arene ring and linear Mn---C---O linkages. The nucleophiles NaBH 4 and LiCH 2C(O)CMe 3 add to [(β-estradiol 3,17-dimethyl ether)Mn(CO) 3]BF 4 (2) in high yield to give the corresponding - and β-cyclohexadienyl manganese tricarbonyl complexes (3). The nucleophiles add meta to the arene -OMe substituent and exo to the metal. The and β isomers of 3 were separated by fractional crystallization and the X-ray structure of the β isomer with an exo-CH 2C(O)CMe 3 substituent is reported (complex 4): space group P2 12 12 1 with a=7.5154(8), b=15.160(2), c=25.230(3) Å, Z=4, V=2874.4(5) Å 3, calc=1.244 g cm −3, R=0.0529 and wR2=0.1176. The molecule 4 has a planar set of dienyl carbon atoms with the saturated C(1) carbon being 0.592 Å out of the plane away from the metal. The results suggest that the manganese-mediated functionalization of aromatic steroids is a viable synthetic procedure with a range of nucleophiles of varying strengths. 相似文献
6.
The methanothermal reactions of M(CO) 6 (M = Mo, W) with Na 2S 2 gave a series of homonuclear clusters [{M(CO) 4} n(MS 4)] 2− (M=Mo, W; N=1, 2), i.e. (Ph 4P) 2[(CO) 4Mo(MoS 4)] (I), (Ph 4P) 2[(CO) 4W(WS 4)] (II), (Ph 4P) 2[(CO) 4Mo(MoS 4)Mo(CO) 4] (III) and (Ph 4P) 2[(CO) 4W(WS 4)W(CO) 4] (IV). The two dimers, I and II, as well as the two trimers, III and IV, are isostructural to each other, respectively. All compounds crystallize in the triclinic space group
with Z=2. The cell dimensions are: a=12.393(8), b=19.303(9), c=11.909(6) Å, =102.39(5), β=111.54(5), γ=73.61(5)°, V=2522(3) Å 3 at T=23 °C for I; a=12.390(3), b=19.314(4), c=11.866(2) Å, =102.66(2), β=111.49(1), γ=73.40(2)°, V=2511(1) Å 3 at T=23 °C for II; a=11.416(3), b=22.524(4), c=10.815(4) Å, =91.03(2), β=100.57(3), γ=88.96(2)°, V=2733(1) Å 3 at T=−100 °C for III, a=11.498(1), b=22.600(4), c=10.864(3) Å, =90.92(2), β=100.85(1), γ=88.58(1)°, V=2771(2) Å 3 at T=23 °C for IV. The dimers are each formed by the coordination of the tetrathiometalate as a bidentate chelating ligand to an M(CO) 4 fragment while addition of another M(CO) 4 fragment to the dimers results in the trimers. All compounds contain both tetrahedral and octahedral metal centers with the formal 6+ and 0 oxidation states, respectively. 相似文献
7.
以福建泉州地区种植的12个姜黄( Curcuma longa)和莪术( Curcuma zedoaria)种质的成熟根茎为试材, 采用正交设计法优化姜黄素(CCM)、单脱甲氧基姜黄素(DMC)和双脱甲氧基姜黄素(BDMC)的提取工艺条件, 比较不同产地姜黄属种质的3种姜黄素类化合物和16种矿质元素的含量。结果表明, 姜黄素类化合物提取工艺为: 100%甲醇, 1:5 (g·mL -1)固液比, 超声提取2分钟, 提取率达到最高值。CCM、DMC和BDMC的最大吸收波长分别为424、418及414 nm; 回归方程分别为 Y=0.170 3 X+0.024 3 (CCM), Y=0.173 8 X+0.041 (DMC), Y=0.140 6 X+0.051 4 (BDMC)。GY03种质中CCM、DMC和BDMC含量分别为1.23%、1.22%与1.50%, 总姜黄素类含量最高, 达3.95%; GY01种质的总姜黄素次之(为3.82%); GY03和GY01可在栽培地推广种植; 12个姜黄属种质的16种矿质元素中, 以Mg、Mn、Al、Fe和Zn含量较为丰富。 相似文献
8.
Kinetic results are reported for intramolecular PPh 3 substitution reactions of Mo(CO) 2(η 1-L)(PPh 3) 2(SO 2) to form Mo(CO) 2(η 2-L)(PPh 3)(SO 2) (L = DMPE = (Me) 2PC 2H 4P(Me) 2 and dppe=Ph 2PC 2H 4PPh 2) in THF solvent, and for intermolecular SO 2 substitutions in Mo(CO) 3(η 2-L)(η 2-SO 2) (L = 2,2′-bipyridine, dppe) with phosphorus ligands in CH 2Cl 2 solvent. Activation parameters for intramolecular PPh 3 substitution reactions: Δ H≠ values are 12.3 kcal/mol for dmpe and 16.7 kcal/mol for dppe; Δ S≠ values are −30.3 cal/mol K for dmpe and −16.4 cal/mol K for dppe. These results are consistent with an intramolecular associative mechanism. Substitutions of SO 2 in MO(CO) 3(η 2-L)(η 2-SO 2) complexes proceed by both dissociative and associative mechanisms. The facile associative pathways for the reactions are discussed in terms of the ability of SO 2 to accept a pair of electrons from the metal, with its bonding transformations of η 2-SO 2 to η 1-pyramidal SO 2, maintaining a stable 18-e count for the complex in its reaction transition state. The structure of Mo(CO) 2(dmpe)(PPh 3)(SO 2) was determined crystallographically: P2 1/ c, A=9.311(1), B = 16.344(2), C = 18.830(2) Å, ß=91.04(1)°, V=2865.1(7) Å 3, Z=4, R( F)=3.49%. 相似文献
9.
以福建泉州地区种植的12个姜黄( Curcuma longa)和莪术( Curcuma zedoaria)种质的成熟根茎为试材, 采用正交设计法优化姜黄素(CCM)、单脱甲氧基姜黄素(DMC)和双脱甲氧基姜黄素(BDMC)的提取工艺条件, 比较不同产地姜黄属种质的3种姜黄素类化合物和16种矿质元素的含量。结果表明, 姜黄素类化合物提取工艺为: 100%甲醇, 1:5 (g·mL -1)固液比, 超声提取2分钟, 提取率达到最高值。CCM、DMC和BDMC的最大吸收波长分别为424、418及414 nm; 回归方程分别为 Y=0.170 3 X+0.024 3 (CCM), Y=0.173 8 X+0.041 (DMC), Y=0.140 6 X+0.051 4 (BDMC)。GY03种质中CCM、DMC和BDMC含量分别为1.23%、1.22%与1.50%, 总姜黄素类含量最高, 达3.95%; GY01种质的总姜黄素次之(为3.82%); GY03和GY01可在栽培地推广种植; 12个姜黄属种质的16种矿质元素中, 以Mg、Mn、Al、Fe和Zn含量较为丰富。 相似文献
10.
The phosphinoalkenes Ph 2P(CH 2) nCH=CH 2 ( n= 1, 2, 3) and phosphinoalkynes Ph 2P(CH 2) n C≡CR (R = H, N = 2, 3; R = CH 3, N = 1) have been prepared and reacted with the dirhodium complex (η−C 5H 5) 2Rh 2(μ−CO) (μ−η 2−CF 3C 2CF 3). Six new complexes of the type (ν−C 5H 5) 2(Rh 2(CO) (μ−η 1:η 1−CF 3C 2CF 3)L, where L is a P-coordinated phosphinoalkene, or phosphinoalkyne have been isolated and fully characterized; the carbonyl and phosphine ligands are predominantly trans on the Rh---Rh bond, but there is spectroscopic evidence that a small amount of the cis-isomer is formed also. Treatment of the dirhodium-phosphinoalkene complexes with (η−CH 3C 5H 4)Mn(CO) 2thf resulted in coordination of the manganese to the alkene function. The Rh 2---Mn complex [(η−C 5H 5) 2Rh 2(CO) (μ−η 1:η 1−CF 3C 2CF 3) {Ph 2P(CH 2) 3CH=CH 2} (η−CH 3C 5H 4)Mn(CO) 2] was fully characterized. Simi treatment of the dirhodium-phosphinoalkyne complexes with Co 2(CO) 8 resulted in the coordination of Co 2(CO) 6 to the alkyne function. The Rh 2---Co 2 complex [(η−C 5H 5) 2Rh 2(CO) (μ−η 1:η 1−CF 3C 2CF 3) {Ph 2PCH 2C≡CCH 3}Co 2(CO) 2], C 37H 25Co 2F 6O 7PRh 2, was fully characteriz spectroscopically, and the molecular structure of this complex was determined by a single crystal X-ray diffraction study. It is triclinic, space group
( Ci1, No. 2) with a = 18.454(6), B = 11.418(3), C = 10.124(3) Å, = 112.16(2), β = 102.34(3), γ = 91.62(3)°, Z = 2. Conventional R on | F| was 0.052 fo observed ( I > 3σ( I)) reflections. The Rh 2 and Co 2 parts of the molecule are distinct, the carbonyl and phosphine are mutually trans on the Rh---Rh bond, and the orientations of the alkynes are parallel for Rh 2 and perpendicular for Co 2. Attempts to induce Rh 2Co 2 cluster formation were unsuccessful. 相似文献
11.
In a search for novel analogues of β 3-adrenoceptor (AR) agonists relaxing the bladder for treatment of urinary dysfunction, 2-[4-(2-{[(1 S,2 R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino}ethyl)phenoxy]-2-methylpropionic acids (1a–e), into which a fibrate-like structure had been incorporated, were synthesised. Compound 1a was found to be a selective β 3-AR agonist in functional assays using the ferret detrusor (β 3-AR), rat uterus (β 2-AR), and rat atrium (β 1-AR); β 3: EC 50=7.8 nM, β 2: IC 50=7,300 nM, β 1: EC 20=23,000 nM. The introduction of a chlorine atom or methyl substituent at the ortho-position on the phenyl ring of 1a further improved β 3-AR selectivity. In an in vivo study, 1a lowered intrabladder pressure (ED 50=31 μg/kg) in rats, without increasing heart rate, in keeping with the in vitro results. Consequently, it is proposed that 1a and its analogues (1b–e), possess β 3-AR agonistic activity in the absence of undesirable β 1- or β 2-AR mediated actions, and may be useful for clinical treatment and pharmacological studies. 相似文献
12.
Three fractions containing hemicellulosic material were obtained by sequential extraction of barley residue (left after removal of water-extractable polysaccharides) with saturated barium hydroxide [Ba(OH) 2 fraction], distilled water [ Ba( OH) 2/ H2O fraction], and 1 m sodium hydroxide [NaOH fraction]. The yields of the fractions were 1.6, 1.7, and 2.6% (w/w), respectively, of the dry barley grist. The Ba(OH) 2 fraction contained mainly arabinose and xylose, 35.8% and 60.9%, respectively. The Ba( OH) 2/ H2O fraction in addition to 26.7% Ara and 36.6% Xyl contained also 34.8% Glc. The NaOH fraction was composed of 14.2% Ara, 44.0% Xyl, and 40.9% Glc. The Ba( OH) 2/ H2O and NaOH extracts were further fractionated by stepwise (NH 4) 2SO 4 precipitation into several subfractions with varying amounts of β-glucans and arabinoxylans. β-Glucans in Ba( OH) 2/ H2O and NaOH fractions were characterized by high ratios of β-(1→4)/β-(1→3) linkages, large amounts of contiguously linked β-(1→4) segments, and high ratios of cellotriosyl/cellotetraosyl units. The alkali-extractable arabinoxylans, especially those NaOH-extractable, were characterized by a very low degree of substitution, high xylose/arabinose ratio, and a small content of doubly substituted xylose residues. Some populations of arabinoxylans displayed structural features that would enable them to self-associate or to interact with β-glucans. 相似文献
13.
The reaction of RuCl 3(H 2O), with C 5Me 4CF 3J in refluxing EtOH gives [Ru 2(η 5-C 5Me 1CF 2) 2 (μ-Cl 2] (20 in 44% yield. Dimer 2 antiferromagnetic (−2 J=200 cm 1). The crystal structures of 2 (rhombohedral system, R3 space group, Z=9, R=0.0589) and [Rh 2(η 5-C 5Me 4CF 3( 2Cl 2(μ-Cl) 2] (3) (rhombohedral system.
space group, Z = 9, R = 0.0641) were solved; both complexes have dimeric structures with a trans arrangement of the η 5-C 5Me 4CF 4 rings. Comparison of the geometry of 2 and 3 with those of the corresponding η 5-C 5Me 5 complexes shows that lowering the ring symmetry causes significant distortion of the M 2(μ-Cl) 2 moiety. The analysis of the MCl 3 fragment conformations in 2 and 3 and in the η 5-C 5ME 5 analogues shows that they are correlated with the M---M distances. The Cl atoms are displaced by Br on reaction of 2 with KBr in MeOH to give the diamagnetic dimer [Ru 2(η 5-C 5Me 4CF 3) 2Br 2 (μ-Br 2] (4). Complex 2 reacts with O 2 in CH 2Cl 2 solution at ambient temperature to form a mixture of isomeric η 6-fulvene dimers [Ru 2(η 6-C 5Me 3CF 3 = CH 2) 2Cl 2(μ-Cl) 2] (5). Reactions of 5 with CO and allyl chloride give Ru(η 5-C 5Me 3CF 3CH 2Cl)(CO) 2Cl (6) and Ru(η 5-C 5Me 3CF 3CF 3CH 2Cl)(η 3-C 3H 5)Cl 2 (7) respectively. 相似文献
14.
Two novel, weakly antiferromagnetically coupled, tetranuclear copper(II) complexes [Cu 4(PAP) 2(μ 2-1,1-N 3) 2(μ 2-1,3-N 3) 2(μ 2-CH 3OH) 2(N 3) 4 (1) (PAP = 1,4-bis-(2′-pyridylamino)phthalazine) and [Cu 4(PAP3Me) 2 (μ 2-1,1-N 3) 2(μ 2-1,3-N 3) 2(H 2O) 2(NO 2) 2]- (NO 3) 2 (2) (PAP3Me = 1,4-bis-(3′-methyl-2′-pyridyl)aminophthalazine) contain a unique structural with two μ 2-1,1-azide intramolecular bridges, and two μ 2-1,3-azide intermolecular bridges linking pairs of copper(II) centers. Four terminal azide groups complete the five-coordinate structures in 1, while two terminal waters and two nitrates complete the coordination spheres in 2. The dinuclear complexes [Cu 2(PPD)(μ 2-1,1-N 3)(N 3) 2(CF 3SO 3)]CH 3OH) (3) and [Cu 2(PPD)(μ 2-1,1-N 3)(N 3) 2(H 2O)(ClO 4)] (4) (PPD = 3,6-bis-(1′-pyrazolyl)pyridazine) contain pairs of copper centers with intramolecular μ 2-1,1-azid and pyridazine bridges, and exhibit strong antiferromagnetic coupling. A one-dimensional chain structure in 3 occurs through intermolecular μ 2-1,1-azide bridging interactions. Intramolecular Cu-N 3-Cu bridge angles in 1 and 2 are small (107.9 and 109.4°, respectively), but very large in 3 and 4 (122.5 and 123.2°, respectively), in keeping with the magnetic properties. 2 crystallizes in the monoclinic system, space group C2/ c with a = 26.71(1), b = 13.51(3), c = 16.84(1) Å, β = 117.35(3)° and R = 0.070, Rw = 0.050. 3 crystallizes in the monoclinic system, space group P2 1/ c with a = 8.42(1), b = 20.808(9), c = 12.615(4) Å, β = 102.95(5)° and R = 0.045, Rw = 0.039. 4crystallizes in the triclinic system, space group P1, with a = 10.253(3), b = 12.338(5), c = 8.072(4) Å, = 100.65(4), β = 101.93(3), γ = 87.82(3)° and R = 0.038, Rw = 0.036 . The magnetic properties of 1 and 2 indicate the presence of weak net antiferromagnetic exchange, as indicated by the presence of a low temperature maximum in χ m (80 K (1), 65 K (2)), but the data do not fit the Bleaney-Bowers equation unless the exchange integral is treated as a temperature dependent term. A similar situation has been observed for other related compounds, and various approaches to the problem will be discussed. Magnetically 3 and 4 are well described by the Bleaney-Bowers equation, exhibiting very strong antiferromagnetic exchange (− 2 J = 768(24) cm −1 (3); − 2 J = 829(11) cm −1 (4)). 相似文献
15.
1. 1. By varying the redox potential of a chloroplast suspension, we obtained new evidence for an equilibrium between states S0 and S1 in the model of Kok, B., Forbush, B. and McGloin, N. (1970, Photochem. Photobiol. 11, 457–475). The mid-point potential of the S0 to S1 couple is close to that for the pool of the electron acceptor of System II, A to A−. 2. 2. The limiting steps between two consecutive photoreactions of System II in Chlorella and spinach chloroplasts, have been studied. 2.1. (a) The limiting step from S1 to S2 (noted γ1 (Δt)) is not exponential. Its temperature coefficient becomes greater as the reaction proceeds. The shape of the kinetics is an intrinsic property of each center. Chloroplasts fixed with 2% glutaraldehyde, show simple first order kinetics. 2.2. (b) The limiting step from S0 to S1 (γ0 (Δt)) exhibits the same characteristics as γ1 (Δt)). 2.3. (c) The limiting step from S2 to S3 (γ2 (Δt)) shows sigmoidal kinetics; two reactions are involved. One of the reactions exhibits the same properties as γ0 (Δt) and γ1 (Δt). 2.4. (d) The limiting step from S3 to S0 (γ3 (Δt)) is a first order reaction, two times slower than the other transitions. This reaction is interpretated in terms of oxygen release.
3. 3. We also studied the limiting steps in the presence of low concentrations (50 μM) of hydroxylamine. The results favor the binding of two molecules of hydroxylamine to every photochemical center.
Abbreviations: DCIP, dichlorophenolindophenol 相似文献
16.
Reaction of (NEt 4) 2MS 4 (M = Mo, W) with CuCl and KSCN (or NH 4SCN) in acetone or acetonitrile affords a new set of mixed metal–sulfur compounds: infinite anionic chains Cu 4(NCS) 5MS 43− (1,2), (CuNCS) 3WS 42− (3) and two dimensional polymeric dianions (CuNCS) 4MS 42− (4,5). Crystal of 1 (M = W) and 3 are triclinic, space group P1(1: a = 10.356(2), b = 15.039(1), c = 17.356(2)Å, = 78.27(1)°, β = 88.89(2)° and γ = 88.60(1)°, Z = 2, R = 0.04 for 3915 independent data;3: a = 8.449(2), b = 14.622(4), c = 15.809(8)Å, = 61.84(3)°, β = 73.67(3)° and γ = 78.23(2)°, Z = 2, R = 0.029 for 6585 independent data). Crystals of 4 (M = W) and 5 (M = Mo) are monoclinic, space group P2 1/ m, Z = 2 (4: a = 12.296(4), b = 14.794(4), c = 10.260(3)Åand β = 101.88(3)°, R = 0.034 for 4450 independent data;5: a = 12.306(2), b = 14.809(3), c = 10.257(2)Åand β = 101.99(3)°, R = 0.043 for 3078 independent data). The crystal structure determinations of 4 and 5 show that four edges of the tetrahedral MS 42− core are coordinated by copper atoms forming WS 4Cu 4 aggregates linked by eight-membered Cu(NCS) 2Cu rings. A two-dimensional network is thus formed in the diagonal (101) plane. The space between the anionic two-dimensional networks is filled with the NEt 4+ cations. Additional NCS groups lead to the [Cu 4(NCS) 5WS 4] 3− (1) trianion connected by NCS bridges forming pseudo-dimers. These latter are held together by weak CuS(NCS) interactions giving rise to infinite chains along a direction parallel to [100]. In contrast complex3 develops infinite chains from WS 4Cu 3 aggregates with the same Cu(NCS) 2Cu bridges as in 4 and 5. These chains are running along a direction parallel to [010]. The structural data of the different types of polymeric compounds containing MS 42− and CuNCS have been used to interpret vibrational spectroscopic data of the thiocyanate groups. 相似文献
17.
Metathesis of [(η 3:η 3−C 10H 16)Ru(Cl) (μ−Cl)] 2 (1) with [R 3P) (Cl)M(μ-Cl)] 2 (M = Pd, Pt), [Me 2NCH 2C 6H 4Pd(μ-Cl)] 2 and [(OC) 2Rh(μ-Cl)] 2 affords the heterobimetallic chloro bridged complexes (η 3:η 3-C 10H 16) (Cl)Ru(μ-Cl) 2M(PR 3)(Cl) (M = Pd, Pt), (η 3:η 3-C 10H 16) (Cl)Ru(μ-Cl) 2PdC 6H 4CH 2NMe 2 and (η 3:η 3-C 10H 16) (Cl)Ru(μ-Cl) 2Rh(CO) 2, respectively. Complex 1 reacts with [Cp *M(Cl) (μ-Cl)] 2 (M = Rh, Ir), [ p-cymene Ru(Cl) (μ-Cl] 2 and [(Cy 3P)Cu(μ-Cl)] 2 to give an equilibrium of the heterobimetallic complexes and of educts. The structures of (η 3:η 3-C 10H 16)Ru(μ-Cl) 2Pd(PR 3) (Cl) ( R = Et, Bu) and of one diastereoisomer of (η 3:η 3-C 10H 16)Ru(μ-Cl) 2IrCp *(Cl) were determined by X-ray diffraction. 相似文献
18.
Complexes of type A 4[VO(tart)] 2· nH 2O, where A = Rb or Cs and tart = d, l-tartrate(4−) ( n = 2) or d,d-tartrate(4−) ( n = 2 for Rb and n = 3 for Cs), were prepared from an aqueous mixture of V 2O 5, AOH and H 4tart. These complexes were studied by single-crystal X-ray diffraction methods: Rb 4[VO( d, l-tart)] 2·2H 2O, space group P1 with a = 8.156(1), b = 8.246(1), c = 8.719(1)Å, = 66.09(1)°, β = 65.07(1)°, γ = 82.40(1)°, Z = 2, 1917 observed reflections, and final Rw = 0.035; Cs 4[VO( d, l-tart)] 2·2H 2O, space group P21/ c with a = 9.350(1), b = 13.728(2), c = 8.479(1)Å, β = 106.77(1)°, Z = 4, 2235 observed reflections, and final Rw = 0.054; Rb 4[VO( d, d-tart)] 2·2H 2O, space group P4122 with a = 8.072(1), c = 32.006(3)Å, Z = 8, 1014 observed reflections and final Rw = 0.038; Cs 4[VO( d, d-tart)] 2·3H 2O, space group P122 with a = 8.184(1), c = 33.680(5)Å, Z = 8, 1310 observed reflections, and final Rw = 0.063. Bulk magnetic susceptibility data (1.5–300 K) for these compounds and A 4[VO l, l-tart)] 2· nH 2O (A = Rb, Cs) were obtained on polycrystalline samples. These data were analyzed in terms of a Van Vleck exchange coupled S = 1/2 model which was modified to include an interdimer exchange parameters Θ. Analysis of the low-temperature (1.5–20 K) susceptibility data gave 2 J = +1.30 cm −1 and Θ = −1.86 K for Rb 4[VO( d, l-tart)] 2·2H 2O, 2 J = +1.16 cm −1 and Θ = −1.69 K for Cs 4[VO( d, l-tart)] 2·2H 2O, 2 J = +1.90 cm −1 and Θ = −0.82 K for Rb 4[VO( d, d-tart)] 2·2H 2O, 2 J = +2.04 cm −1 and Θ = −0.80 K for Rb 4[VO( l, l-tart)] 2·2H 2O, 2 J = +1.52 cm −1 and Θ = −0.25 K for Cs 4[VO( d, d-tart)] 2·3H 2O, and 2 J = +1.64 cm −1 and Θ = −0.31 K for Cs 4[VO( l, l-tart)] 2·3H 2O. These results suggest the magnitudes of intradimer (ferromagnetic and interdimer (antiferromagnetic) exchange interactions are similar in these complexes, as observed for the analogous Na salts. 相似文献
19.
The ligand 1,4,7-triazacyclononane-1,4,7-tris[2′( R)-2′-propionate](-3)(( R)-tacntp 3−), binds stereospecifically to transition metal ions. The structures of the complexes [Cr(( R)-tacntp)]·NaBr and [Fe(( R)-tacntp)]·H 2O have been determined by X-ray crystallography. Both complexes have the Λ-configuration but the conformation of the chelate rings in Λ-[Cr(( R)-tacntp)] is (λ,λ,λ) with a geometry close to octahedral while in Λ-[Fe(( R)-tacntp)] it is (δ,δ,δ) and the geometry is closer to that of a trigonal prism. Chiral induction in the electron transfer reactions of Λ-[Co(( R)-tacntp)], Λ-[Fe(( R)-tacntp)] and Λ-[Mn(( R)-tacntp)] with [Co(( RR,SS)-chxn) 3] 2+ has been investigated. All three reactions are outer-sphere and four isomeric [Co(( RR,SS)-chxn) 3] 3+ products are identified in each case. The oxidants Λ-[Fe(( R)-tacntp)] and Λ-[Mn(( R)-tacntp)] show very similar selectivities, quite different from those of Λ-[Co(( R)-tacntp)]. Reasons for this behavior are discussed. 相似文献
20.
The mammalian Per1 gene is one of the most important components of circadian clock function of the suprachiasmatic nucleus and peripheral tissues. We examined whether the β 2-adrenoceptor agonists, procaterol and fenoterol, induce human Per1 mRNA expression in human bronchial epithelium. The in vitro stimulation of β 2-adrenoceptor agonists in BEAS-2B cells led to a remarkable increase in the level of h Per1 mRNA. Moreover, fenoterol or procaterol induced the phosphorylation of CREB in BEAS-2B cells as verified by immunoblot analysis. β 2-adrenoceptor agonists induced human Per1 mRNA expression by the signaling pathways of cAMP-CREB in BEAS-2B cells. 相似文献
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