Brown David A, Fitzpatrick Noel J, Müller-Bunz Helge, Ryan Aine T
School of Chemistry and Chemical Biology, Centre for Synthesis and Chemical Biology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
Inorg Chem. 2006 May 29;45(11):4497-507. doi: 10.1021/ic050849m.
Attempts to produce Zn analogues of the structural model complexes [M2(mu-O2CR)2(O2CR)2(mu-H2O)(tmen)2] (M = Ni, Co, Mn; R = CH(3), C(CH3)3, CF3) by the reaction of a series of zinc carboxylates with N,N,N',N'-tetramethylethylenediamine (tmen), resulted in the mononuclear complexes [Zn(OAc)(2)(tmen)] (1) and [Zn(crot)2(tmen)].(0.5)H2O (2) for R = CH3 and (CH)2CH3, respectively, and the dinuclear complexes [Zn(2)(mu-piv)(2)(piv)(2)(mu-H2O)(tmen)2] (3) and [Zn2(mu-OAc(F))2(OAc(F))2(mu-H2O)(tmen)2] (4) for R = C(CH3)3 and CF3, respectively. In contrast to the analogous imidazole series, i.e., [M2(mu-O2CR)2(O2CR)2(mu-H2O)(Im)4] (M = Ni, Co, Mn; R = CH3, C(CH3)3, CF3), zinc carboxylates react with imidazole to give only the mononuclear complexes [Zn(OAc)2(Im)2] (5), [Zn(crot)2(Im)2].H2O (6), [Zn(piv)2(Im)2].(0.5)H2O (7), and [Zn(OAc(F))2(Im)2] (8). Reaction of 1, 2, and 3 with either acetohydroxamic acid (AHA) or benzohydroxamic acid (BHA) gives the dinuclear complexes [Zn2(O2CR)3(R'A)(tmen)], where R'A = acetohydroxamate (AA) (9, 10, 11) or benzohydroxamate (BA) (13, 14, 15). In these complexes, the zinc atoms are bridged by a single hydroxamate and two carboxylates, with a capping tmen ligand on one zinc and a monodentate carboxylate bonded to the second zinc atom. This composition models closely the observed structure of the active site of the p-iodo-d-phenylalanine hydroxamic acid inhibited Aeromonas proteolyticaaminopeptidase enzyme. In contrast, 4 reacts with AHA to give [Zn2(OAc(F))3(tmen)2(AA)] (12) with an additional tmen ligand so that both Zn atoms are 6-coordinate, whereas reaction with BHA gives the trinuclear complex [Zn3(OAc(F))4(tmen)2(BA)2] (16). Reactions of 3 and 4 with glutarodihydroxamic acid (GluH2A2) produce the tetranuclear complexes [Zn4(piv)6(tmen)4(GluA2)] (18) and [Zn4(OAc(F))6(tmen)4(GluA2)] (19).
通过一系列羧酸锌与N,N,N',N'-四甲基乙二胺（tmen）反应，试图制备结构模型配合物[M2(μ-O2CR)2(O2CR)2(μ-H2O)(tmen)2]（M = Ni、Co、Mn；R = CH(3)、C(CH3)3、CF3）的锌类似物，分别得到了R = CH3和(CH)2CH3时的单核配合物[Zn(OAc)(2)(tmen)]（1）和[Zn(crot)2(tmen)].(0.5)H2O（2），以及R = C(CH3)3和CF3时的双核配合物[Zn(2)(μ-piv)(2)(piv)(2)(μ-H2O)(tmen)2]（3）和[Zn2(μ-OAc(F))2(OAc(F))2(μ-H2O)(tmen)2]（4）。与类似的咪唑系列，即[M2(μ-O2CR)2(O2CR)2(μ-H2O)(Im)4]（M = Ni、Co、Mn；R = CH3、C(CH3)3、CF3）不同，羧酸锌与咪唑反应仅得到单核配合物[Zn(OAc)2(Im)2]（5）、[Zn(crot)2(Im)2].H2O（6）、[Zn(piv)2(Im)2].(0.5)H2O（7）和[Zn(OAc(F))2(Im)2]（8）。1、2和3与乙酰氧肟酸（AHA）或苯甲羟肟酸（BHA）反应得到双核配合物[Zn2(O2CR)3(R'A)(tmen)]，其中R'A = 乙酰氧肟酸酯（AA）（9、10、11）或苯甲羟肟酸酯（BA）（13、14、15）。在这些配合物中，锌原子由一个单羟肟酸酯和两个羧酸盐桥连，一个锌上有一个封端的tmen配体，第二个锌原子上键合有一个单齿羧酸盐。这种组成与对碘-d-苯丙氨酸羟肟酸抑制的解蛋白气单胞菌氨肽酶酶活性位点的观察结构密切相似。相比之下，4与AHA反应得到[Zn2(OAc(F))3(tmen)2(AA)]（12），带有一个额外的tmen配体，使得两个锌原子都是六配位的，而与BHA反应得到三核配合物[Zn3(OAc(F))4(tmen)2(BA)2]（16）。3和4与戊二双羟肟酸（GluH2A2）反应生成四核配合物[Zn4(piv)6(tmen)4(GluA2)]（18）和[Zn4(OAc(F))6(tmen)4(GluA2)]（19）。
