混合溶剂热条件下DL-Trp晶体生成过程的研究

 以L-Trp和碳酸钕为原料，通过混合溶剂热法制得DL-Trp晶体，并进行红外光谱、单晶X-衍射等表征。该化合物属单斜晶系P2(1)/c空间群，具有中心对称结构。a=1.890 8(2) nm, b=0.572 67(11) nm,c=0.930 32(15) nm，Z=4。此晶体通过′C-O-H-N′氢键缔合作用形成三维空间构型。对构型转变原因进行了分析。通过测定溶液体系旋光度-时间曲线可知，L色氨酸构型变化是一个渐变过程，降温至90 ℃左右是色氨酸发生构型转变最显著的温度范围。

Investigation on Crystallization of DL-Tryptophan by Mixed Solvent-thermal Method

The DL tryptophan (DLTrp) crystal was prepared by the mixed solvent thermal method between neodymium carbonate and L tryptophan. The structure was characterized by FTIR, single crystal X-ray diffraction analyses. The results indicated that the cyrstallized DL Trp molecule possessed a centrosymmetric monoclinic space group P2(1)/c with a=1.89 08(2) nm, b=0.572 67(11) nm,c=0.930 32(15) nm and Z=4. It showed a three dimensional structure assembled by hydrogen bond of ′C-O-H-N′ interactions. The reasons for changing in configuration and the mechanism of the reaction were investigated by the curves of optical rotation and reaction time. The result indicated the transformation in configuration was a gradual change process. The temperature around 90 ℃ was important for configuration transforming of Trp.