Nitrosation of N-methylhydroxylamine by nitroprusside. A kinetic and mechanistic study
作者:María Marta Gutiérrez、Graciela Beatriz Alluisetti、José Antonio Olabe、Valentín Tomás Amorebieta
DOI:10.1039/b805329d
日期:——
complex reacts through a competitive one-electron-transfer path, forming the [Fe(CN)5NO]3- ion with slow production of small quantities of N2O. The stoichiometry and mechanism of the main adduct-formation path are similar to those previously reported for hydroxylamine (HA) and related nucleophiles. The nitrosated product, MeN(NO)OH, decomposes thermally at physiological temperatures, slowly yielding NO
Na2 [Fe(CN)5NO] .2H2O(五氰基亚硝酰基高铁酸钠(II),硝普钠,SNP)和MeN(H)OH(N-甲基羟胺,MeHA)水溶液之间的反应动力学已被研究-可见光谱,使用互补溶液技术:FTIR / ATR,EPR,质谱和同位素标记(15NO),pH范围为7.1-9.3,I = 1 M(NaCl)。主要产物是N-甲基-N-亚硝基羟胺(MeN(NO)OH)和[Fe(CN)5H2O] 3-,其特征为[Fe(CN)5(pyCONH2)] 3-配合物(pyCONH2 =异烟酰胺) 。用Me2NOH(N,N-二甲基羟胺,Me2HA)作为亲核试剂未发生反应。速率定律为:R = kexp [Fe(CN)5NO2-] x [MeN(H)OH] x [OH-],其中kexp = 1.6 +/- 0.2x10(5)M(-2)s(- 1),在25.0摄氏度下,DeltaH#= 34 +/- 3 kJ mol(-1),DeltaS#=-32