The structure of the proton skeleton in 1,3-butadieneiron Tricarbonyl as determined from the NMR spectra of oriented molecules

¹H NMR spectra of 1,3-butadieneiron tricarbonyl oriented in a nematic liquid crystal solvent have been analysed and used to derive the structure of the proton skeleton, which is found to be non-planar. The distance of the anti protons from the plane defined by the remaining four protons is 0.77 ± 0.06 ±.     

Evidence for proton pairs in γ-AIOOH (boehmite) from NMR absorption spectra

Continuous-wave and Fourier transform NMR absorption spectra have been recorded for pure γ-AIOOH at room temperature and 130K. The well-resolved doublet lineshape shows that there are proton pairs (intrapair separation $\text{R ? 1.7}$ Å), the presence of which has not previously been recognized. A structural model based on the occupation of two sites consistent with the space group Cmcm is proposed.     

Getting the most from your laboratory information system in the hematology laboratory

As laboratories continue to downsize, commercialize and become more businesslike in today’s managed care environment, their present and future success will greatly depend on the efficiency and flexibility of their laboratory information system (LIS). Today, LIS is a primary tool for managing business and communication. Laboratories that hope to remain competitive in today’s dynamic health care must continue to implement new and innovative approaches with their LISs. Received: 26 July 2002 Accepted: 6 August 2002 Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium     

Diastereoselective α-Alkylation of β-Amino Esters: Preparation of Novel α-Substituted β-Amino Esters from α-Amino Acids

b-Amino acids and their derivatives have attracted considerable attention in recent years due to their occurrence in biologically active natural products, such as dolastatins 11, cyclohexylnorstatine 22 and taxol 33. bAmino acids also find application in the synthesis of blactams4, piperidines5, indolizidines6. Moreover, the peptides consisting of bamino acids, the so called bpeptides, have been extensively studied recently7. Consequently, considerable efforts have been directed to the synt…     

构建助力学生全方位成长的化学实验课程助教体系

Based on decades of experiences on involving teaching assistants for laboratory teaching, College of Chemistry and Molecular Engineering at Peking University developed a complete set of teaching assistant management regulations and guidelines, including recruitment, lab-teaching training, supervising, and performance assessment of teaching assistants, to effectively improve laboratory teaching and to provide a platform which is beneficial to multi-dimensional development as well as future career of undergraduates.     

播种化学梦铸造科学魂——西北大学化学科普实验室的实践与反思

Under the background of college entrance examination reform, it becomes imperative to improve the students' interest in chemistry. During the effort to investigate how to present the chemistry knowledge, to cultivate and promote students' interest and professional attitude towards chemistry, we developed the public science education laboratory of College of Chemistry and Materials Science, Northwest University. In the current paper, we introduced the background of setting-up, the missions and targets of the laboratory, as well discussed the construction, evaluation systems and prospection of the laboratory.     

Our expedition in the construction of fluorescent supramolecular metallacycles

During the past few years, the construction of fluorescent supramolecular metallocycles has attracted extensive attention due to their diverse applications such as sensing, photoelectric devices, and mimicking complicated natural photo-processes. In this review, we will discuss how we entered the field of fluorescent supramolecular metallacycles and what we investigated in this field. The preparation of various fluorescent supramolecular metallacycles and their applications in monitoring the dynamics of coordination-driven self-assembly, sensing, catalysts, and supramolecular gels will be summarized.     

A novel variant of the medicinally relevant 1,2,5-benzothiadiazepin-4-one-1,1-dioxide scaffold accessed via the downstream modification of Castagnoli-Cushman lactams

Downstream modification of piperazin-2-ones obtained by the Castagnoli-Cushman reaction leads to a novel version of the medicinally relevant 1,2,5-benzothiadiazepin-4-one-1,1-dioxide scaffold. The relative stereochemistry remained trans as evidenced by the spectroscopic data and the single-crystal X-ray analysis.     

Cephasinenoside A,a new cephalotane diterpenoid glucoside from Cephalotaxus sinensis

A new cephalotane diterpenoid glucoside, cephasinenoside A (1), was isolated from the twigs and leaves of Cephalotaxus sinensis (Rehd. et Wils.) Li. The structure of 1 was established on the basis of spectroscopic analyses and ECD calculations. Compound 1 represents the first cephalotane diterpenoid glycoside which inhibits the proliferation of human acute myeloid leukemia HL-60 cells with a GI₅₀ value of 7.17 ± 1.03 μM.