共查询到20条相似文献,搜索用时 31 毫秒
1.
The North American tallgrass prairie is composed of a diverse mix of C 3 and C 4 plant species that are subject to multiple resource limitations. C 4 grasses dominate this ecosystem, purportedly due to greater photosynthetic capacity and resource-use efficiency associated with C 4 photosynthesis. We tested the hypothesis that intrinsic physiological differences between C 3 and C 4 species are consistent with C 4 grass dominance by comparing leaf gas exchange and chlorophyll fluorescence variables for seven C 4 and C 3 herbaceous species (legumes and non-legumes) in two different settings: experimental mesocosms and natural grassland sites. In the mesocosms, C 4 grasses had higher photosynthetic rates, water potentials and water-use efficiency than the C 3 species. These differences were absent in the field, where photosynthetic rates declined similarly among non-leguminous species. Thus, intrinsic photosynthetic advantages for C 4 species measured in resource-rich mesocosms could not explain the dominance of C 4 species in the field. Instead, C 4 dominance in this ecosystem may depend more on the ability of the grasses to grow rapidly when resources are plentiful and to tolerate multiple limitations when resources are scarce. 相似文献
2.
The characteristic surface lipid compositions of several C 3 and C 4 plants are discussed. C 4 plants produce surface lipids (epicuticular waxes) made up of the ubiquitous classes of aliphatic compounds: free fatty acids, aldehydes, primary alcohols, alkanes and aliphatic linear esters. C 3 plants synthesize surface lipids comprising the ubiquitous classes and either of the two following groups of compound: (i) lβ-diketones, hydroxy lβ-diketones, alkan-2-ol esters; (il) ketones and secondary alcohols with the functional group in the middle of the hydrocarbon chain. These features are suggested to represent physioIogical characteristics of the plant and to be related to ecological adaptations. Wax class compositions might also be an ancillary method for defining the C 3 or C 4 mechanism of CO 2 assimilation in cases where uncertainty exists. 相似文献
3.
Panicum milioides, a naturally occurring species with C 4-like Kranz leaf anatomy, is intermediate between C 3 and C 4 plants with respect to photorespiration and the associated oxygen inhibition of photosynthesis. This paper presents direct evidence for a limited degree of C 4 photosynthesis in this C 3-C 4 intermediate species based on: 1. (a) the appearance of 24% of the total 14C fixed following 4 s photosynthesis in 14CO2-air by excised leaves in malate and aspartate and the complete transfer of label from the C4 acids to Calvin cycle intermediates within a 15 s chase in 12CO2-air; 2. (b) pyruvate- or alanine-enhanced light-dependent CO2 fixation and pyruvate stimulation of oxaloacetate- or 3-phosphoglycerate-dependent O2 evolution by illuminated mesophyll protoplasts, but not bundle sheath strands; and 3. (c) NAD-malic enzyme-dependent decarboxylation of C4 acids at the C-4 carboxyl position, C4 acid-dependent O2 evolution, and 14CO2 donation from [4-14C]C4 acids to Calvin cycle intermediates during photosynthesis by bundle sheath strands, but not mesophyll protoplasts.
However, P. milioides differs from C4 plants in that the activity of the C4 cycle enzymes is only 15 to 30% of a C4 Panicum species and the Calvin cycle and phosphoenolpyruvate carboxylase are present in both cell types. From these and related studies (Rathnam, C.K.M. and Chollet, R. (1979) Arch. Biochem. Biophys. 193, 346–354; (1978) Biochem. Biophys. Res. Commun. 85, 801–808) we conclude that reduced photorespiration in P. milioides is due to a limited degree of NAD-malic enzyme-type C4 photosynthesis permitting an increase in pCO2 at the site of bundle sheath, but not mesophyll, ribulosebisphosphate carboxylase-oxygenase. 相似文献
4.
We have integrated two cDNAs expressing Sorghum photosynthetic phosphoenolpyruvate carboxylase (C 4-PEPC) and NADP-malate dehydrogenase (cpMDH), two key enzymes involved in the primary carbon fixation pathway of NADP-malic enzyme-type C 4 plants, separately or together into a C 3 plant (potato). Analysis of the transgenic plants showed a 1.5-fold increase in PEPC and cpMDH activities compared to untransformed plants. Immunolocalization confirmed an increase at the protein level of these two enzymes in the transgenic plants and indicated that the Sorghum cpMDH was specifically addressed to the chloroplasts of potato mesophyll cells. However, integration of either or both of the cDNAs into the potato genome did not appear to significantly modify either tuber starch grain content or the rate of photosynthetic O 2 production compared to control untransformed plants. The low level of transgene expression probably explains the lack of influence on carbon metabolism and photosynthetic rates. This general observation suggests that some complex mechanism may regulate the level of production of foreign C 4 metabolism enzymes in C 3 plants. 相似文献
5.
[NBu n4] 2[W(C 3Se 5) 3] (C 3Se 52− = 1,3-diselenole-2-selone-4,5- diselenolate(2−)) was prepared by the reaction of Na 2[C 3Se 5] with WCl 6 in ethanol, followed by addition of [NBu n4]Br. The cyclic voltammogram in dichloromethane exhibits two oxidation peaks at −0.04 and +0.03 V (versus SCE). The complex reacted with [Fe(C 5Me 5) 2][BF 4], iodine or [TTF] 3[BF 4] 2 (TTF ·+ = the tetrathiafulvalenium radical cation) in acetonitrile to afford the oxidized complexes [Fe(C 5Me 5) 2] 0.5[W(C 3Se 5) 3], [NBu n4] 0.1[W(C 3Se 5) 3] and [TTF] 0.5[W(C 3Se 5) 3], respectively. Current-controlled electrochemical oxidation of the complex in acetonitrile gave [NBu n4] 0.6[W(C 3Se 5) 3]. The oxidized complexes exhibit electrical conductivities of 4.7×10 −5−1.5×10 −3 S cm −1 at room temperature measured for compacted pellets. Electronic absorption, IR and ESR spectra of these complexes are discussed. 相似文献
6.
用5种实验方法对东北草原区233种植物光合类型进行鉴定,并对其相对分布随纬度变化关系及其与土壤含盐量和PH值的关系进行分析.在此基础上对几种典型C 3、C 4牧草适应于盐碱环境的生理特点进行深入研究结果表明,在所鉴定的233种植物中,C 3植物有144种,隶属于28科94属,C 4植物有89种;隶属于17科55属,在高纬度地区C 3植物表现出更高的生长优势,在纬度较低和盐碱化区域,C 4植物分布具相对优势.尤其在盐碱化程度较重的地区,C 4植物成为明显的优势种,分布上的差别决定于它们对环境适应机制上的差异C 3植物对盐碱环境适应机制主要通过积累脯氨酸等有机溶质进行渗透调节,而C 4植物主要通过液泡中离子区域化积累作用进行调节,并且与C 3植物相比对盐碱环境具更强的适应能力. 相似文献
7.
UV photolysis of Ru 3(CO) 12 physisorbed onto porous Vycor glass leads to the oxidative addition product (μ-H)Ru 3(CO) 10(μ-OSi). The latter reacts thermally with 1-pentene to form a stable adduct, HRu 3(CO) 10(OSi)(1-C 5H 10), and photolysis of the adduct results in isomerization of the alkene. HRu 3(CO) 10(OSi)(1-C 5H 10) + hv → (μ-H)Ru 3(CO) 10(μ-OSi) + 2-pentene As with other photoactivated hybrid systems, the cis-/trans-2-pentene product ratio changes during photolysis. Unlike the other systems, where light generates a thermal catalyst, the data gathered here indicate a photoassisted catalytic process in which photoactivation of HRu 3(CO) 10(OSi)(1-C 5H 10) leads to an excited state similar to a π-allyl complex. 相似文献
8.
Cp #2Yb (Cp #=C 5H 4(CH 2) 2NMe 2) has been obtained by reaction of YbI 2(THF) 2 with 2 equiv. of C 5H 4(CH 2CH 2NMe 2)K in THF. The X-ray structure analysis shows a bent structure with intramolecular coordination of both nitrogen atoms to ytterbium. The reaction of C 60-fullerene with Cp #2Yb leads to the formation of the fullerenide derivative [Cp #2Yb] 2C 60, which shows an ESR signal in the solid state and in THF solution at room temperature (solid: Δ H = 50 G, G = 1.9992; solution: Δ H = 10 G, G = 2.0001) and a magnetic moment of 3.6 BM. The lutetium fullerenides CpLu(C 60)(DME) (3) and Cp *Lu(C 60)(DME)(C 6H 5CH 3) (4), (Cp = η 5−C 5H 5, Cp * = η 5−C 5Me 5), were obtained by reaction of C 60 with CpLu(C 10H 8) (DME) and Cp *Lu(C 10H 8) (DME) in toluene. Both complexes are paramagnetic (μ eff = 1.4 and 0.9 BM) and exhibit temperature-dependent ESR signals (293 K: g = 1.992 and 2.0002 respectively). 相似文献
9.
HRu 2Fe 2PdC(CO) 12 (η 3-ß-C 10H 15) cluster was prepared in the reaction of (Et 4N) [HFe 2Ru 2C(CO) 12] with [Pd(η 3-ß-C 10H 15)Cl] 2. X-ray structural study of HRu 2Fe 2PdC(CO) 12 (η 3-ß-C 10H 15) (where ß-C 10H 15 is ß-pinenyl) revealed a wing-tip butterfly geometry of the metal core and (1R, 2S, 3S, 5R) absolute configuration for both crystallography independent molecules in the crystal. Chiroptical properties of this cluster are compared with other clusters containing a Pd(η 3-ß-C 10H 15) fragment and discussed. 相似文献
10.
Reactions of [Rh(COD)Cl] 2 with the ligand RN(PX 2) 2 (1: R = C 6H 5; X = OC 6H 5) give mono- or disubstituted complexes of the type [Rh 2(COD)Cl 2{ν 2−C 6H 5N(P(OC 6H 5) 2) 2}] or [RhCl{ν 2−C 6H 5 N(P(OC 6H 5) 2) 2 }] 2 depending on the reaction conditions. Reaction of 1 with [Rh(CO) 2Cl] 2 gives the symmetric binuclear complex, [Rh(CO)Cl{μ−C 6H 5N(P(OC 6H 5) 2) 2} 2, whereas the same reaction with 2 (R = CH 3; X = OC 6H 5) leads to the formation of an asymmetric complex of the type [Rh(CO)(μ−CO)Cl{μ−CH 3N(P(OC 6H 5) 2) 2} 2 containing both terminal and bridging CO groups. Interestingly the reaction of 3 (R = C 6H 5, X = OC 6H 4Br− p with either [Rh(COD)Cl] 2 or [Rh(CO) 2Cl] 2 leads only to the formation of the chlorine bridged binuclear complex, [RhCl{ν 2−C 6H 5N(P(OC 6H 4Br− p) 2) 2}] 2. The structural elucidation of the complexes was carried out by elemental analyses, IR and 31P NMR spectroscopic data. 相似文献
11.
The natural abundance of C 3 and C 4 plants is affected by multiple environmental factors including temperature, moisture balance and atmospheric pCO 2. The relative importance of these factors is a subject of considerable debate, and may vary in different natural ecosystems. Previous studies generally focus on single loess sequences in the Chinese Loess Plateau, and conflicting conclusions on C 4/C 3 have been reached when studying carbon isotope ratios in carbonate and organic matter. In this paper we report a comprehensive carbon isotopic characterization of total organic carbon (TOC) and individual higher plant leaf waxes from five loess sequences spanning the last 35 ka from the Chinese Loess Plateau (CLP). The five coring sites encompass large gradients of annual mean temperature (9.2–13.9 °C) and precipitation (402–673 mm), allowing us to assess the controlling mechanisms on C 4/C 3 plant ratios. Glacial–interglacial sequences provide carbon isotope data for comparison with other climatic and environmental proxies such as lithology and magnetic susceptibility. Our results demonstrate that increased C 4/C 3 ratios are positively correlated with higher temperature and increased summer rainfall which characterize stronger summer monsoon in all five sites. We conclude C 4 abundance increases from the last glacial to the Holocene in response to greater monsoon activity and that the C 4 expression is suppressed in the cold and drier intervals. 相似文献
12.
The hydrothermal reactions of (Ph 4P)[VO 2Cl 2] and H 2C 2O 4 at 150 and 125°C yield (Ph 4P) 2[V 2O 2(H 2O) 2(C 2O 4) 3]·4H 2O (1) and (Ph 4P)[VOCl(C 2O 4)] (2), respectively. The structure of the molecular anion of 1 consists of a binuclear unit of oxovanadium(IV) octahedra bridged by a bisbidentate oxalate group. The VO 6 coordination geometry at each vanadium site is defined by a terminal oxo group, an aquo ligand, and four oxygen donors — two from the bisbidentate bridging oxalate and two from the terminal bidentate oxalate. The structure of 2 consists of discrete Ph 4P + cations occupying regions between [VOCl(C 2O 4)] −∞ spiral chains. The structure of the one-dimensional anionic chain exhibits V(IV) octahedra bridged by bisbidentate oxalate groups. Crystal data: 1·4H 2O, monoclinic P2 1/ n, A = 12.694(3), B = 12.531(3), C = 17.17(3) Å, β = 106.32(2)°, V = 2621.3(13) Å 3, Z = 2, Dcalc = 1.501 g cm −3, structure solution and refinement converged at a conventional residual of 0.0518; 2, tetragonal P4 3, A = 12.145(2), C = 15.991(3) Å, V = 2358.7(12) Å 3, Z = 4, R = 0.0452. 相似文献
13.
The crystalline ion pair [Co 2{OOC---CCo 3(CO) 9} 5, C 10H 6(N(CH 3) 2) 2H] (1) presents unusual magnetic properties. The X-band EPR spectrum of 1 at room temperature presents two unresolved bands at g=1.98 and 4.55. At a low temperature (20 K), the cluster of clusters 1 presents a complicated spectrum with an intense signal at 1700 G. The magnetic susceptibility of 1 was fit to a two spin S1= S2=3/2 Heisenberg model, with J=11.2 cm −1 and a g value of 2.3. There is no field dependence of the magnetization, which suggests intramolecular coupling between the two tetrahedral centers of the cluster. Molecular orbital modeling indicates a sigma path of exchange between two topologically non-equivalent cobalt(II) centers. 相似文献
14.
The reaction between the linear trinuclear complex [Pt{Fe(CO) 3(NO)} 2(PhCN) 2] and Ph 2(2-C 5H 4N)PSe led to the isolation and characterization of the 46-electron cluster [(CO) 3Fe(μ 3-Se){Pt(CO)P(2-C 5H 4N)Ph 2} 2] (1), whose structure has been determined by X-ray diffraction methods. The cluster typology, which consists of an open triangle Pt---Fe---Pt capped by a μ 3-Se atom, is rather rare. The chemical bonding in 1 and in similar systems has been analyzed through density functional theory (DFT) and qualitative MO approaches. A strict analogy with the well understood L 2M(μ-acetylene)ML 2 systems is invoked by considering 1 as formed by the (CO) 3FeSe tetrahedral unit stabilized by sidewise interactions of the triple bond with two d 10-L 2M fragments. Otherwise, the 18-electron (CO) 3FeSe monomer is unstable as an isolate molecule. This is confirmed by our DFT calculations that indicate how the well characterized dimer (CO) 3Fe(μ-Se 2)Fe(CO) 3 lies as much as, approximately, 58 kcal mol −1 deeper in energy. Finally, by considering an analogy with [L 2M(μ-dichalcogen)ML 2] 0, +2 redox systems (M=Pd, Pt), reduction of 1 to a dianion has been hypothesized and the structure of the latter has been tentatively explored by DFT calculations. 相似文献
15.
The amino-functionalized metallocene (C 5H 4CH(Me)NMe 2) 2ZrCl 2, [(Cp N) 2ZrCl 2] was synthesized by salt metathesis of ZrCl 4 and 2 equiv. of C 5H 4CH(Me)NMe 2Li. The metallocene was obtained in good yield as a mixture of rac and meso diastereomers as established by NMR spectroscopy. The addition of 2 equiv. of n-BuLi to the metallocene (Cp N) 2ZrCl 2 produced a co-catalyst system which was active, at a 1.0 mol% loading, in the dehydropolymerization of PhSiH 3 to poly(phenylsilane), PPSi. The PPSi was obtained as a 9:1 linear–cyclic mixture ( Mw=3850, Mn=2300) as established by GPC analysis; 29Si{ 1H} NMR spectroscopy revealed an atactic polymer microstructure. 相似文献
16.
Three novel methylene bridged binuclear iron(II) complexes: (R,R′ = i-C 3H 7 (6); R = i-C 3H 7, R′ = CH 3 (7); R,R′ = CH 3 (8))} have been synthesized. Activated by Al( i-Bu) 3, complex 6 shows very poor activity for the polymerization of ethylene at one bar ethylene pressure, whereas, 7 and 8 exhibit much higher activity than mononuclear iron catalysts {[ArNC(Me)C 5H 3N(Me)CNAr′]FeCl 2 (Ar,Ar′ = 2,6-C 6H 3- i-Pr (9); Ar = 2,6-C 6H 3- i-Pr 2, Ar′ = 2,6-C 6H 3–Me 2 (10); Ar,Ar′ = 2,6-C 6H 3–Me 2 (11))}. The molecular weight ( Mw) of PE produced by 7 and 8 are in the range 13.2–46.0 × 10 4 and much higher than those produced by mononuclear iron catalysts 9 and 10. GPC results demonstrate that 7 and 8 yield PE with a broad/bimodal molecular weight distribution (MWD). In contrast, 9 and 10 yield PE with relatively narrow and unimodal MWD (4.26 and 3.55). Elevating the temperature and Al/Fe molar ratio will narrow the MWD of PE. 相似文献
17.
The aqueous chemistry of vanadium with physiologically relevant ligands constitutes a subject of burgeoning research, extending from bacterial metalloenzymic functions to human-health physiology. Vanadium, in the form of VCl 3 and V 2O 5, reacted expediently with citric acid, in a 1:2 molar ratio in water at pH4, and, in the presence of various cations, afforded crystalline materials bearing the general formula (Cat) 2[V 2O 4(C 6H 6O 7) 2]· nH 2O (A) (Cat +=Na +, NH 4 +, n=2; Me 4N +, K +, n=4). Exploration of the reactivity of A toward H 2O 2 yielded the peroxo-containing complexes (Cat) 2[V 2O 2(O 2) 2(C 6H 6O 7) 2]·2H 2O (B) (Cat +=K +, NH 4 +). Both classes of compounds were characterized analytically and spectroscopically. The X-ray structures of complexes A and B emphasize the exceptional stability of the dimeric rhombic unit V V 2O 2, which is retained upon H 2O 2 reaction, and the preserved mode of coordination of the citrate ligand as a doubly deprotonated moiety. In these complexes, typical six and eight coordination numbers were observed for the Na + and K + counter-ions, respectively. The variety of synthetic approaches leading to A, along with the stepwise and direct assembly and isolation of peroxo-compounds (B), denotes the significance of reaction pathways and intermediates in vanadium(III–V)–citrate synthetic chemistry. Hence, a systematic investigation of reactivity modes in aqueous vanadium–citrate systems emerges as a crucial tool for the establishment of chemical interconnectivity among low MW complex species, potentially participating in the intricate biodistribution of that metal ion in biological fluids. 相似文献
18.
The reactions of [(H 5C 6) 3P] 2ReH 6− with (CH 3CN) 3Cr(CO) 3, (diglyme)Mo(CO) 3 or (C 3H 7CN) 3W(CO) 3 led to the formation of [(H 5C 6) 3P] 2ReH 6M(CO) 3− (M = Cr, Mo, W) complexes. These have been characterized by IR and NMR spectroscopies, as well as elemental analyses. A single crystal X-ray diffraction study has also been carried out for the M = Cr complex as a K(18-crown-6) + salt. The complex crystallizes as a THF monosolvate in the monoclinic space group P2 1/ n with a = 22.323(6), B = 9.523(2), C = 27.502(5) Å, β = 104.98(2) 0 and V = 5648 Å 3 for Z = 4. The Re---Cr separation is 2.5745(12) Å, and the two phosphine ligands are oriented unsymmetrically. Although the hydride ligands were not found, the presence of three bridging hydrides and a dodecahedral coordination geometry about rhenium could be inferred. Low temperature 1H and 31P NMR spectroscopic studies did not reveal the low symmetry of the solid state structure. 相似文献
19.
Abstract— Cultured mouse neuroblastoma cells (clone N18) contained a homologous series of gangliosides, G M3, G M2, G M1 and G D1a; the total lipid bound sialic acid (LBSA) was 3.3 nmol per mg of protein, of which G D1a comprised two-thirds. In contrast, neonatal hamster astrocytes (clone NN) and human glioblastoma cells (Cox clone) contained mainly G M3, which represented 95% of the 2 nmol of LBSA per mg protein in these cells. When the cells were grown in the presence of [ 14C]galactose, label was incorporated into all of the gangliosides isolated from the cells. The labeling pattern corresponded to the ganglioside composition of the cell lines; G D1a was more extensively labeled in N18 cells and G M3 was the major labeled ganglioside extracted from glial cells. In addition to in rivo biosynthesis, in vitro synthesis of gangliosides was also determined. The activities of five glycosyltransferases of the ganglioside biosynthetic pathway were measured in homogenates of the three cell lines. The neuroblastoma cells contained all five enzyme activities whereas the two glial cell lines were deficient in UDP- N -acetylgalactosamine: G M3 N -acetylgalactosaminyltransferase activity, which catalyzes the synthesis of G M2 from G M3. The results indicated that cells of neuronal origin contain the more complex gangliosides associated with CNS and the requisite biosynthetic enzymes and that cells of glial origin are missing these complex gangliosides and the key glycosyltransferase required for their synthesis. 相似文献
20.
Condensation of Z-PPh 2CH 2C(Bu t)=NNH 2 with 4-nitroacetophenone gave the azine phosphine Z,E-PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 4NO 2-4) (I). The corresponding phsophine oxide II was prepared by treatment of I with H 2O 2. The phosphine I with [Mo(CO) 4(nbd)] (nbd=norbornadiene) gave [Mo(CO) 4{PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 4NO 2-4)}] (1a); the corresponding tungsten 1b and chromium 1c complexes were made similarly. The crystal structure of 1a was determined by X-ray diffraction and showed the presence of a six-membered chelate ring with the bulky 4-nitrophenyl group held close to the metal. Oxidation of 1a with bromine gave the seven-coordinate molybdenum (II) complex 2. Treatment of [PtMe 2(cod)] (cod=cycloocta-1,5-diene) with I at 20°C gave the dimethyl-platinum (II) complex [PtMe 2{PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 4NO 2-4)}] (3a) which with MeI gave the iodotrimethylplatinum(IV) complex 4. Treatment of 3a with C≡O opened the chelate ring to give the dimethyl(carbonyl)platinum(II) complex 5 containing a monodentate phosphine ligand. When 3a was heated in toluene solution at 110°C it gave the cyclometallated methylplatinum(II) complex [PtMe{PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 3NO 2-4)}] (6). Treatment of 6 with MeI gave the platinum(IV) complex 7. The dichloropalladium(II) complex [PdCl 2{PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 4NO 2-4)}] (3b) was prepared by treatment of [PdCl 2(NCPh) 2] with I in CH 2Cl 2. Treatment of [PtCl 2(NCMe) 2] with 2 equiv. of I gave the trans-bis(phosphine) complex 8. When 2 equiv. of I were treated with [PtCl 2(cod)] followed by NH 4PF 6 this gave the salt 9a containing two six-membered chelate rings; the analogous palladium(II) 9b) salt was also prepared. Treatment of 2 equiv. of I with [PtCl 2(cod)] followed by NH 4PF 6 gave the PF 6 salt 10 containing a six-membered chelate ring and a monodentate ligand. When 10 was treated with AgNO 3 followed by NH 4PF 6 this gave the bis-chelate complex 11 containing five- and six-membered chelate rings. Treatment of [IrCl(CO) 2( p-toluidine)] with I gave the cyclometallated iridium(III) hydride complex [IrHClCO{PPh 2CH 2C(Bu t)=N-N=CMe(C 6H 3NO 2-4)}] (12). [RuCl 2(PPh 3) 3] with the phosphine I resulted in the Ru(II) complex 13 in which the ortho hydrogens of the 4-nitrophenyl group are agostically interacting with ruthenium. Proton, Phosphorus-31, some carbon-13 NMR and IR data have been obtained. Crystals of 1a are orthorhombic, space group Pna2 1, with a = 1819.3(2), b = 1050.0(1), c = 1614.8(2) pm and Z = 4; final R = 0.0191 for 2616 observed reflections. 相似文献
|