N,N'-二-[5-甲氧基-3-溴-2(5H)-4-呋喃酮基]-1,2-乙二胺的合成及其晶体结构(英文)

通过串联迈克尔加成-消除反应合成了N,N'-二-[5-甲氧基-3-溴-2(5H)-4-呋喃酮基]-1,2-乙二胺,利用IR、UV、1H NMR、13C NMR、MS、元素分析和X射线单晶衍射对其进行表征.X射线单晶衍射结果表明:标题化合物包含两个平面的呋喃酮环和两个手性中心,并通过N(1)-H(1A)…O(1)分子间氢键和Br(1)…O(2)近距离作用形成超分子结构.     

5-(N-2-羟乙基)羟乙酰氨基-N,N'-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺的合成

5-氨基-N,N'-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(2)在N,N-二甲基乙酰胺中可直接与乙酰氧基乙酰氯反应,产物再经碱性水解得5-羟乙酰氨基-N,N'-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(3),后者再与氯乙醇反应生成5-(N-2-羟乙基)羟乙酰胺基-N,N'-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(1),经乙二醇甲醚/正丁醇重结晶,纯度高于99%(HPLC),反应总收率由39.3%(文献值)提高到55.1%.     

N,N'-双-三唑甲基-[2,2]的合成及晶体结构

标题化合物由N,N′-双-甲氧基甲基_[2,2]和1H_1,2,4-三唑在无溶剂的情况下反应得到。它的单晶X射线分析表明晶体属正交晶系,空间群为Pca2_1,晶胞参数:a=9.986(3)、b=12.932(6)、c=17.135(6)A,z=4。结构用直接法解出,经块矩阵最小二乘法修正,最后的R=0.042。该冠醚环的C—C、N—C与O—C的平均键长分别为1.50(1)、1.40(1)、1.43(1)A,三唑(a)与(b)的五个键长的平均值皆为1.33(1)A。     

Liquid-crystalline oxovanadium(IV) complexes accessed from bidentate [N,O] donor salicylaldimine Schiff-base ligands

A series of bis[4-(n-alkoxy)-N-(4′-R-phenyl)salicylideneiminato]oxovanadium(IV) complexes (n?=?6,?10,?14,?16,?18 and R?=?C₃H₇) were prepared and their mesogenic properties were investigated. The mesomorphic behaviors of the compounds were studied by polarized optical microscopy and differential scanning calorimetry. Ligands display SmA/SmC and unexpected nematic mesophases. The complexes bearing longer alkoxy carbon chain (n?=?10,?14,?16, and 18) showed both monotropic or enantiotropic transitions with smectic A and high ordered smectic E phases. However, the complex with shorter carbon chain length (n?=?6) showed monotropic transition with an unprecedented nematic (N) phase. A density functional theory study was carried out using DMol3 at BLYP/DNP level to obtain a stable optimized structure. A square-pyramidal geometry for the vanadyl complexes has been suggested. A ν_V=O stretching value of ～970?cm^?1 corroborated absence of any V?=?O?···?V?=?O interactions. Cyclic voltammetry revealed a quasireversible one-electron response at 0.61?V for the VO(IV)–VO(V) redox couple. Variable temperature magnetic susceptibility measurements of the vanadyl complexes suggested absence of any exchange interactions among the vanadyl spin centers.