center ligated to at least one carboxamido nitrogen. Both the carbonyl and N-O stretching frequencies (nu(CO) and nu(NO)) of the present and related complexes strongly suggest a [low-spin Mn(II)-NO*] formulation for 5. The alternative description [low-spin Mn(I)-NO+] is not supported by the spectroscopic and redox behavior of 5. Complex 5 is the first example of a [Mn-NO]6 nitrosyl that exhibits photolability
                                    五齿
配体N,N-双(2-
吡啶甲基甲基)胺-N-乙基-2-
吡啶-2-羧酰胺(PaPy3H; H是可分解的羧酰胺H)的Mn(II)和Mn(III)配合物,即,[Mn(PaPy3)(
H2O)] 
ClO4(1)和[Mn(PaPy3)(Cl)]     (2),具有结合的羧酰胺氮,已被分离和表征。1中的高自旋Mn(II)中心对双氧非常敏感,当与Cl-在空气中反应时,该配合物迅速转变为2。由于类似的席夫碱配合物[Mn(SBPy3)Cl]     (4)非常抗氧化,因此1中结合的羧酰胺氮对这种氧化负责。NO与1的反应生成抗磁性的[Mn-NO] 6亚
硝酰基[Mn(PaPy3)(NO)]     (5)。没有键合的羧酰胺基氮的络合物(例如4和[Mn(PaPy3H)(Cl)2](3))不会与NO反应。Mn(III)配合物2和[Mn(PaPy3)(MeCN)] 2+均未观察到与NO的反应。这些反应共同表明,NO