Maiti Debabrata, Woertink Julia S, Ghiladi Reza A, Solomon Edward I, Karlin Kenneth D
Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Inorg Chem. 2009 Sep 7;48(17):8342-56. doi: 10.1021/ic900975y.
Our continuing efforts into developing copper coordination chemistry relevant to dioxygen-processing copper proteins has led us to design and synthesize a cyclotriveratrylene (CTV)-based trinucleating ligand, CTV-TMPA, which employs tetradentate tris(2-pyridylmethyl)-amine chelates (TMPA) for their copper ion binding sites. Binding of three copper ions per CTV-TMPA unit was established by various chemical and spectroscopic methods such as UV-vis and resonance Raman (rR) spectroscopies. The following complexes were observed: A tricopper(I) complex (CTV-TMPA)Cu(I)(3) (1), a CO adduct (CTV-TMPA)Cu(I)(3)(CO)(3) (1-CO; nu(C=O) = 2094 cm(-1)), a triphenylphosphine adduct (CTV-TMPA)Cu(I)(3)(PPh(3))(3) (1-PPh(3)), a tricopper(II) complex (CTV-TMPA)Cu(II)(3) (1-Ox), and its tris-monochloride or tris-monobromide adducts. Also, introduction of dioxygen to the -80 degrees C solutions of 1 leads to O(2)-adducts, the first example of a synthetic copper complex which can stabilize a mononuclear Cu(II)-superoxo and dinuclear peroxo species simultaneously within one complex {[Cu] = 1.53 mM in THF: (mu-1,2-peroxo complex, lambda(max) = 543 (epsilon 9650) nm): nu(O-O) = 825 ((Delta(18)O(2)) = -47) cm(-1); nu(Cu-O) = 506 ((Delta(18)O(2)) = -26) cm(-1): (superoxo complex, lambda(max) = 427 (epsilon 3150) nm): nu(O-O) = 1129 ((Delta(18)O(2)) = -60) cm(-1); nu(Cu-O) = 463 ((Delta(18)O(2)) = -27) cm(-1)}. Elemental sulfur reacts reversibly with 1 leading to a (proposed) hexanuclear species {(CTV-TMPA)Cu(II)(3)}(2)(mu-1,2-S(2)(2-))(3) (1-S) {lambda(max) = 544 (epsilon 7270) nm}, possessing one dicopper(II)-disulfide structural type: {THF solvent) nu(S-S) = 489 ((Delta(34)S) = -10) cm(-1); nu(Cu-S) = 307 ((Delta(34)S) = -5) cm(-1)}. Derivation of spectroscopic, structural, and chemical conclusions were aided by the study of a close mononuclear analogue with one pyridyl group of the TMPA parent possessing a 6-CH(2)OCH(3) substituent, this being part of the CTV-TMPA architecture.
我们在开发与双加氧处理铜蛋白相关的铜配位化学方面的持续努力，促使我们设计并合成了一种基于环三聚藜芦烯（CTV）的三核配体CTV-TMPA，它利用四齿三（2-吡啶甲基）胺螯合物（TMPA）作为其铜离子结合位点。通过紫外可见光谱和共振拉曼光谱等多种化学和光谱方法确定了每个CTV-TMPA单元结合三个铜离子。观察到以下配合物：三铜（I）配合物(CTV-TMPA)Cu(I)(3)（1）、一氧化碳加合物(CTV-TMPA)Cu(I)(3)(CO)(3)（1-CO；ν(C=O)=2094 cm(-1)）、三苯基膦加合物(CTV-TMPA)Cu(I)(3)(PPh(3))(3)（1-PPh(3)）、三铜（II）配合物(CTV-TMPA)Cu(II)(3)（1-Ox）及其三氯化物或三溴化物加合物。此外，将双加氧引入到1在-80℃的溶液中会生成O(2)加合物，这是合成铜配合物中首个能在一个配合物中同时稳定单核Cu(II)-超氧和双核过氧物种的例子{在四氢呋喃中[Cu]=1.53 mM：（μ-1,2-过氧配合物，λ(max)=543（ε9650）nm）：ν(O-O)=825（(Δ(18)O(2))=-47）cm(-1)；ν(Cu-O)=506（(Δ(18)O(2))=-26）cm(-1)：（超氧配合物，λ(max)=427（ε3150）nm）：ν(O-O)=1129（(Δ(18)O(2))=-60）cm(-1)；ν(Cu-O)=463（(Δ(体8)O(2))=-27）cm(-1)}。元素硫与1可逆反应生成一种（推测的）六核物种{(CTV-TMPA)Cu(II)(3)}(2)(μ-1,2-S(2)(2-))(3)（1-S）{λ(max)=544（ε7270）nm}，其具有一种二铜（II）-二硫结构类型：{四氢呋喃溶剂）ν(S-S)=489（(Δ(34)S)=-10）cm(-1)；ν(Cu-S)=307（(Δ(34)S)=-5）cm(-1)}。通过研究TMPA母体的一个吡啶基带有6-CH(2)OCH(3)取代基的紧密单核类似物，辅助得出光谱、结构和化学方面的结论，该类似物是CTV-TMPA结构的一部分。
