2-(1H-苯并咪唑-2-基)-3-苯丙烯腈类化合物的电喷雾质谱裂解方式研究

Study on the fragment pathways of electrospray ionization mass spectroscopy of 2-( 1H-benzimidazole-2-yl)-3-phenylacrylonitrile derivatives

目的探讨2-（1H-苯并咪唑-2-基）-3-苯丙烯腈类化合物的质谱裂解规律。方法分别在正离子和负离子检测模式下,解析2-（1H-苯并咪唑-2-基）-3-苯丙烯腈类化合物的主要特征碎片离子以及可能的裂解途径。结果在正离子模式下,1~16号化合物二级质谱主要有[M＋H-HR2]＋、[M＋H-NH]＋和[M＋H-HCN]＋3个特征离子峰。其中1~10号化合物[M＋H-HR2]＋特征离子进一步三级质谱可裂解为碎片离子峰218、217、77;12~16号化合物[M＋H-HR2]＋特征离子进一步三级质谱可裂解为碎片离子峰244[M＋H-HR2-HR1]＋。17~18号化合物在正离子模式下,二级质谱主要有[M＋H-HR2]＋、[M＋H-HR3]＋2个特征离子峰;[M＋H-HR3]＋特征离子峰进一步三级质谱可裂解为碎片离子峰[M＋H-HR3-HR2]＋、[M＋H-HR3-NH]＋、[M＋H-HR3-HCN]＋。在负离子模式下,1~18号化合物二级质谱主要有[M-HHCN]-1个特征离子峰,1~11号化合物进一步三级质谱可裂解为碎片离子峰216。结论 2-（1H-苯并咪唑-2-基）-3-苯丙烯腈类化合物二级质谱主要有3条裂解途径,当苯并咪唑环上氮或苯环上有取代时都将发生裂解,氮上有取代的化合物裂解易于苯环上有取代的化合物。

Objective To study the fragment pathways of electrospray ionization mass spectroscopy of 2-（ 1H-benzimidazole-2-yl）-3-phenylacrylonitrile derivatives. Methods In positive or negative mode,the main fragment ions and the fragment pathways of 2-（ 1H-benzimidazole-2-yl）-3-phenylacrylonitrile derivatives were analyzed. Results In positive mode,the ion peaks of MS / MS of 1-16 compounds were mainly [M＋H-HR2]＋,[M ＋ H-NH]＋and [M ＋ H-HCN]＋; The ion peaks of MS3 of [M ＋ H-HR2]＋from 1-10 compounds were mainly 218,217 and 77; The ion peaks of MS3 of [M＋H-HR2]＋from 12-16 compounds were mainly 244 [M＋H-HR2-HR1]＋; The ion peaks of MS2 of 17-18 compounds were mainly [M＋HHR2]＋and [M＋H-HR3]＋; The ion peaks of MS3 of [M＋H-HR3]＋from 17-18 compounds were mainly[M＋H-HR3-HR2]＋,[M＋H-HR3-NH]＋,and [M＋H-HR3-HCN]＋. In negative mode,the ion peaks of MS2 of 1-18 compounds were mainly [M-H-HCN]-,and ion peaks of MS3 of 1-11 compounds were 216.Conclusion There were three main pathways of MS / MS of 2-（ 1H-benzimidazole-2-yl）-3-phenylacrylonitrile derivatives. When there were some replacing functional group in the C or N of benzimidazole,functional group would be lost in the fragment pathways. The functional group in the N was easier lost than that in the C.