Synthesis and Crystal Structure of Trans-diaquabis(hexamethylenetetramine-N)bis(isothiocyanato)cobalt(Ⅱ) trans-tetraaquabis(isothiocyanato)cobalt(Ⅱ) dihydrate

1 INTRODUCTION Supramolecular compounds assembled by coordination covalent bonding or hydrogen bonding are of considerable interest due to their potential applications in developing new materials with magnetic, optical and catalytic properties[1]. One of the synthesis methods used to construct the functional compounds is that octahedral metal ion connects to polydentate ligand such as 4, 4?bipyridine, pyrazine and so on to form multi-dimensional supramolecular polymer[2]. Hmt (hexamethyl…     

Al2O3-TiO2二元氧化物的制备条件对酸性的影响

用两种方法制备了Al₂O₃-TiO₂二元氧化物。经不同温度焙烧后,用Hammett指示剂滴定法、吡啶吸附IR法、正丁胺——TPD法对其表面酸性质进行了测定。结果表明：随着Al₂O₃含量增加,Al₂O₃-TiO₂二元氧化物的总酸量、酸强度和L酸比例都增加;随着焙浇温度的增大,总酸量下降,L酸比例和酸强度较大的酸量、百分数则增加。     

异噁唑啉基咪唑[1,2-a]吡啶C-核苷类化合物的合成

以异恶唑啉基环取代呋喃核糖环（ribose ring）为基本单元,成功地合成了一系列咪唑[1,2-a]吡啶衍生物的C－核苷化合物3和4（其中碱基和异恶唑啉基环之间以C－C化学键方式连接）。这两种异构体中N和O原子处于相互交换的位置,分别可以利用相应的烯烃和腈氧化物中间体进行偶极环合加成反应制得。