Bowman W Russell, Burchell Colin J, Kilian Petr, Slawin Alexandra M Z, Wormald Philip, Woollins J Derek
Department of Chemistry, Loughborough University, Loughborough LE11 3TU, UK.
Chemistry. 2006 Aug 16;12(24):6366-81. doi: 10.1002/chem.200501528.
The synthesis and full characterisation of a series of 1,2,4-thiadiazoles is reported. (SCN)(x) has been studied by a variety of techniques and the data compared with 1,2,4-thiadiazole and 1,2,4-dithiazoles. The observed data suggest that the polymer consists of 1,2,4-dithiazole rings linked by nitrogen atoms. For (SCN)(x), the MALDI-TOF mass spectroscopy showed a parent ion at 1149 and a series of peaks with (SCN)(2) repeat units (116 m/z); this result implies that (SCN)(2) may be the monomer unit of the polymer. Its IR spectrum shows a very broad peak with maximum at 1134 cm(-1) consisting of several overlapping peaks in the same region as ring vibrations for 1,2,4-thiadiazole and 1,2,4-dithiazole compounds. Peaks in the Raman spectrum in the range 400-480 cm(-1) support the presence of disulfide units within the polymer. The solid-state (13)C NMR (99 % (13)C-labelled) spectrum is dominated by two singlets of equal intensity at approximately 187 and 184 ppm with low intensity peaks in the range 152-172 ppm, in approximately the same range as both 1,2,4-thiadiazoles and 1,2,4-dithiazoles. The solid-state (15)N NMR (99 % (15)N labelled) spectrum displays two major peaks of similar intensity at 236.9 and 197.2 ppm, which are clearly very different environments to those observed in bis(3-bromo-1,2,4-thiadiazol-5-yl) disulfide, but similar to 1,2,4-dithiazoles. The X-ray structures of seven C-S-N systems are reported. Preliminary studies on (SeCN)(x) suggest that literature references to this polymer may be in error with the red solid actually being red selenium.
报道了一系列1,2,4 - 噻二唑的合成及全面表征。已通过多种技术对(SCN)ₓ进行了研究，并将数据与1,2,4 - 噻二唑和1,2,4 - 二噻二唑进行了比较。观察到的数据表明该聚合物由通过氮原子连接的1,2,4 - 二噻二唑环组成。对于(SCN)ₓ，基质辅助激光解吸电离飞行时间质谱（MALDI - TOF）显示母离子峰位于1149，以及一系列带有(SCN)₂重复单元（116 m/z）的峰；该结果表明(SCN)₂可能是该聚合物的单体单元。其红外光谱显示在1134 cm⁻¹处有一个非常宽的峰，最大值由在与1,2,4 - 噻二唑和1,2,4 - 二噻二唑化合物的环振动相同区域的几个重叠峰组成。拉曼光谱中400 - 480 cm⁻¹范围内的峰支持聚合物中存在二硫键单元。固态¹³C NMR（99%¹³C标记）光谱主要由两个强度相等的单峰主导，分别位于约187和184 ppm，在152 - 172 ppm范围内有低强度峰，该范围与1,2,4 - 噻二唑和1,2,4 - 二噻二唑大致相同。固态¹⁵N NMR（99%¹⁵N标记）光谱在236.9和197.2 ppm处显示两个强度相似的主要峰，这与在双(3 - 溴 - 1,2,4 - 噻二唑 - 5 - 基)二硫化物中观察到的环境明显不同，但与1,2,4 - 二噻二唑相似。报道了七个C - S - N体系的X射线结构。对(SeCN)ₓ的初步研究表明，文献中对该聚合物的描述可能有误，实际的红色固体是红色硒。
