丁烯二酸二丁酯配体异构化的研究

用市售的未经分离提纯的顺丁烯二酸二丁酯与W(CO)4(phen)(phen=1,10-邻菲咯啉)在甲苯中加热回流24h，反应液经硅胶柱层析分离得到两个产物，分别用甲苯/石油醚重结晶，获得橙黄色块状晶体(1)和橙红色片状晶体(2)。用X射线衍射法测定其晶体结构分别为W(CO)2(phen)(DBF)2(1)与W(CO)2(phen)(DBF)(DBM)(2)(DBM=顺丁烯二酸二丁酯，DBF=反丁烯二酸二丁酸)。经对原料中的DBM和DBF含量的分析及对两种产物中DBF总量的计算表明配体DBM很可能在配位反应过程中有部分异构化为更稳定的配体DBF.

Study on lsomerizatin of the ligand dibutyl maleate

The tungsten complex W(CO)4(phen)(phen=1,10-phenanthroline) reacted in toluene refluxing for 24 hours with unpurified dibutyl maleate, which was commercially purchased, to give a dark brown solution. The solution was separated by column chromatography on silica gel and two main chromatographic bainds were collected. The orange block crystals (1) and the red orange platelet crystals (2) were obtained by slow diffusion of petroleum ether into the toluene solutions of the two bands respectively.The crystal structures are W(CO)2(phen) (DBF)2(1) and W(CO)2(phen)(DBF)(DBM) (2) (DBF=dibutyl fumarate, DMB=dibutyl maleate), determined by the X-ray diffraction method. In the molecules of both crystals tungsten atom coordination is distorted octahedral with the two CO groups and phen in the equatorial plane and the metal binds in an η^2 fashion to C-C bonds of DBM or DBF. Grystal data for complex 1: space group R-3, a=3.026 4 (4) nm , b=3.026 4(4) nm,c=2.135 2 (4) nm, α=90°, β=90°, γ=120°. V=16.936(4) nm^3, Dc=1.547 g/cm^3, Z=18, R=0.49 1 for 6 624 independent reflections. Crystal data for complex 2: space group P2 (1)/n, a=1.038 2(2) nm, b=1.428 1 (3) nm, c=2.530 3(5) nm, α＝90°,β =92.74(3)°, γ＝90°, V=3.747 (0) nm^3, Dc=1.554g/cm^3, Z=4, R=0.039 3 for 8 562 independent reflections. The analysis of the contents for DBM and DBF in the unpurified dibutyl maleate and the quantitative calculation for the total content of DBF in the two products indicate that in the coordination reaction the ligand DBM was probably partly isomerized into DBF which is more stable.