Coordination of extraframework Li+ cation in the MCM-22 and MCM-36 zeolite: FTIR study of CO adsorbed

Nature and population of Li⁺ cationic sites in MCM-22 zeolite and its pillared form (MCM-36) were investigated by means of adsorption of CO as a probe molecule. CO stretching frequency and adsorption heat were measured by FTIR spectroscopy and adsorption microcalorimetry. Intrazeolitic carbonyl complexes on Li⁺ cations in MCM-22 and MCM-36 are characterized by two main vibrational bands at 2,195 and 2,188 cm^?1. Band at higher wavenumbers is ascribed to carbonyls on Li⁺ ions coordinated only to two oxygen atoms at the intersection of 10-ring channels and interacting with CO molecule by energy around 45 kJ mol^?1. Band at 2,188 cm^?1 was assigned to the carbonyls on Li⁺ cations located on top of 5 or 6-rings on the channel walls and coordinated to three or four oxygen atoms, interacting with CO molecule by energy 33–36 kJ mol^?1. Effect of pillaring and layered form of zeolite on nature and population of Li⁺ cationic sites is also discussed, as well as the formation of dicarbonyl complexes.     

The synthesis and characterisation of an expansive additive for M-type cements

The expansion effect of laboratory-prepared expansive additives for M-type expansive cement was investigated at the early stage of hydration by the multicell isoperibolic calorimeter and volumetric technique based on Archimedes’ principle. The relative volume changes and heat released during hydration are strongly affected by the content of lime in the expansive additive due to the influence of CaO on the kinetics and mechanism of formation of ettringite. The increasing content of lime favours the formation of monosulphate and its later transformation to ettringite generating expansion stress. The effect of expansive additive on the behaviour of mortar samples was measured as linear elongation of test blocks using Graf-Kaufman dilatometer. Lower or higher content of lime in expansion additive slightly decreases the 7th-day compressive and flexural strength of samples while this effect is negligible for expansive additive with nominal composition of ettringite.     

微铂电极上1-酰基二茂铁动力学参数的测定

本文合成并研究了１－酰基二茂铁在ＣＨ２Ｃｌ２中的伏安行为，测定了它们在ＣＨ２Ｃｌ２中不同支持电解质浓度时的扩散系数，并分明用Ｚ．Ｇａｌｕｓ和Ｋ．Ａｏｋｉ方法计算了两种状态下的电子迁移速率常数。讨论了取代基的诱导效应和共轭效应及其链长对１－酰基二茂铁的动力学性质的影响以及支持电解质及其浓度等因素对伏安曲线的影响。     

自生氧化铝颗粒增强铝基复合材料的扫描电镜和原子力显微镜的对比研究

用扫描电镜（ＳＥＭ）、原子力显微镜（ＡＦＭ）等分析技术研究了一种Ａｌ／Ａｌ２Ｏ３自生颗粒复合材料的微观形貌，结果表明，７００～７５０℃气－液反应生成的氧化铝自生颗粒的典型尺寸为亚微米级，颗粒与基体之间具有热力学稳定性。     

The application of Py-GC/MS for the catalytic upgrading of oil separated from summer food waste leachate

The catalytic cracking of oil fractions separated from summer food waste leachate was investigated over BEA zeolite and Al-SBA-15 catalysts. In this study, a mixture of food waste oil fractions and catalyst was directly introduced to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), with the resulting vapor phase products being simultaneously analyzed. Various acid compounds, including oleic acid, produced by the non-catalytic pyrolysis of food waste leachate were reformed into valuable compounds, such as oxygenates, hydrocarbons, and aromatics. The BEA zeolite catalyst showed higher selectivity for hydrocarbon compounds, especially aromatics, within the gasoline range due to its superior cracking ability originating from its highly acidic sites. Conversely, the cracking performance of the Al-SBA-15 catalyst, possessing mild acidic sites, was lower than that of the BEA zeolite. Increasing the amount of Al-SBA-15 catalyst enhanced the cracking activity and resulted in higher selectivity for hydrocarbons.     

Triazoles and tetrazoles: Prime ligands to generate remarkable coordination materials

The current great interest in preparing functional metal-organic materials is inevitably associated with tremendous research efforts dedicated to the design and synthesis of new families of sophisticated multi-nucleating ligands. In this context, the N-donor triazole and tetrazole rings represent two categories of ligands that are increasingly used, most likely as the result of the recent dramatic development of “click chemistry” and Zeolitic Imidazolate Frameworks (ZIFs). Thus, azole-based complexes have found numerous applications in coordination chemistry.In the present review, we focus on the utilization of 1,2,3-triazole, 1,2,4-triazole and tetrazole ligands to create coordination polymers, metal complexes and spin-crossover compounds, reported to the end of 2009. In the first instance, we present a compendium of all the relevant ligands that have been employed to generate coordination polymers and Metal-Organic Frameworks (MOFs). Due to the huge amount of reported MOFs and coordination polymers bearing these azole rings, three representative examples for each category (therefore nine in total) are described in detail. The second section is devoted to the use of the bridging abilities of these azole ligands to prepare metal complexes (containing at least two metal centers). Given the large number and the great structural diversity of the polynuclear compounds found in the literature, these have been grouped according to their nuclearity. Finally, in the last section, the triazole- and tetrazole-containing coordination compounds exhibiting spin-crossover properties are presented.     

Etherification of Ferrocenyl Alcohol by Highly‐efficient Ytterbium Triflate

Nucleophilic substitution of ferrocenyl alcohols with various aliphatic alcohols in the presence of a catalytic amount of ytterbium triflate [Yb(OTf)₃] was studied. It was found the unsymmetrical ferrocenyl ethers could be easily obtained in excellent yields when the reactions were performed in primary and secondary alcohols. However, in other organic non‐alcoholic solvents such as acetonitrile, the formation of symmetrical ferrocenyl ethers rather than unsymmetrical ones was observed.     

Synthesis of 32‐phenyl‐substituted methyl E/Z‐pyropheophorbide‐a's from methyl E/Z‐pyropehophorbide‐a 131‐ketoximes

Methyl E/Z‐pyropheophorbide‐a 13¹‐ketoximes 2a,b and their O‐acetyl derivatives 3a,b were oxidized with osmium(VIII) oxide to give aldehydes 4a,b and 5a,b , respectively. The Wittig reactions of the aldehyde chlorines 4a,b and 5a,b with benzyltriphenylphosphonium chloride were performed to form the corresponding methyl (3¹E/Z,13¹E/Z)‐3²‐phenylpyropheophorbide‐a 13¹‐ketoximes 6aa‐bb and their O‐acetyl derivatives 7aa‐bb ; hydrolysis of these ketoximes 6aa,ba and 6ab,bb in formic acid produced methyl (E/Z)‐3²‐phenylpyropheophorbide‐a's 8a,b .     

Mn（OAc）2/Schiff base as a new efficient catalyst system for the Henry reaction of nitroalkanes with aldehydes

A series of novel Schiff bases bearing triazole structure were synthesized and characterized by IR and NMR.Mn（OAc）₂/Schiff base efficiently catalyzed Henry reaction of nitroalkanes with aldehydes to produce the corresponding products of β-nitroalcohols, under mild conditions with high yields（up to 99%）.A reaction mechanism is proposed based on the experimental results.