2,3-二氰基-5,6-二(2-噻吩基)-1,4-吡嗪、[(CN)2Th2Pyz]及其钯(II)配合物[(CN)2Th2Pyz(PdCl2)2]和相关的五金属吡嗪卟啉嗪[(PdCl2)4Th8TPyzPzM]（M = Mg(II)(H2O)，Zn(II)）中顺式 2-噻吩基环的结构柔性及其作用。

Structural flexibility and role of vicinal 2-thienyl rings in 2,3-dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)2Th2Pyz], its palladium(II) complex [(CN)2Th2Pyz(PdCl2)2], and the related pentametallic pyrazinoporphyrazines [(PdCl2)4Th8TPyzPzM] (M = Mg(II)(H2O), Zn(II)).

机构信息

Dipartimento di Chimica, Università Sapienza, P.le A. Moro 5, I-00185 Rome, Italy.

出版信息

Inorg Chem. 2011 Dec 5;50(23):12116-25. doi: 10.1021/ic201678p. Epub 2011 Oct 31.

DOI:10.1021/ic201678p

PMID:22040347

Abstract

The solid state and solution structure of 2,3-dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)(2)Th(2)Pyz], and its Pd(II) derivative, [(CN)(2)Th(2)Pyz(PdCl(2))(2)]·H(2)O, formed by reaction of [(CN)(2)Th(2)Pyz] with [(C(6)H(5)CN)(2)PdCl(2)] were characterized by X-ray, UV-visible, (1)H and (13)C NMR, and extended X-ray absorption fine structure (EXAFS) spectral measurements. The X-ray crystal structure of [(CN)(2)Th(2)Pyz] shows the presence of one thienyl ring positioned orthogonal to the rest of the molecule, with the two vicinal thienyl rings lying orthogonal to each other in a rare arrangement. NMR studies of [(CN)(2)Th(2)Pyz] in the solid state and in solutions of dimethylformamide or dimethyl sulfoxide confirm a nonequivalence of the thienyl rings in the solid state and also in solution. EXAFS results indicate that two distinct Pd(II) coordination sites are formed at the di(2-thienyl)pyrazino moiety of [(CN)(2)Th(2)Pyz(PdCl(2))(2)]·H(2)O, with identical Pd-N(pyz) (2.03(3) Å) and Pd-Cl (2.36(3) Å) bond lengths but with different Pd-S1 (2.25(4) Å) and Pd-S2 (3.21(5) Å) bond distances in an overall asymmetric molecular framework. Density functional theory (DFT) and time-dependent DFT (TDDFT) theoretical studies also provide information about the structure and spectral behavior of the precursor and its metalated Pd(II) derivative. (1)H/(13)C NMR and UV-visible spectral measurements were also carried out on two heteropentametallic porphyrazine macrocycles which were prepared by a reaction of PdCl(2) with [Th(8)TPyzPzM] where Th(8)TPyzPz = tetrakis-2,3-[5,6-di-(2-thienyl)-pyrazino]porphyrazinato dianion and M = Mg(II)(H(2)O) or Zn(II). Spectroscopic data on the newly synthesized [(PdCl(2))(4)Th(8)TPyzPzM] compounds suggest that the binding of PdCl(2) involves coordination sites of the type S(2(th))PdCl(2) with the two thienyl rings of each di(2-thienyl)pyrazino fragment bound to Pd(II) in an equivalent manner ("th-th" coordination). This is similar to what was found for the corresponding octapyridinated analogues ("py-py" coordination).

摘要

2,3-二氰基-5,6-二(2-噻吩基)-1,4-吡嗪[(CN) 2 Th 2 Pyz]及其 Pd(II)衍生物[(CN) 2 Th 2 Pyz(PdCl 2 ) 2 ]·H 2 O 的固态和溶液结构，通过[(CN) 2 Th 2 Pyz]与[(C 6 H 5 CN) 2 PdCl 2 ]反应形成，通过 X 射线、紫外-可见、(1)H 和(13)C NMR 以及扩展 X 射线吸收精细结构(EXAFS)光谱测量进行了表征。[(CN) 2 Th 2 Pyz]的 X 射线晶体结构表明存在一个噻吩环与分子的其余部分垂直定位，两个相邻的噻吩环以罕见的方式彼此垂直排列。[(CN) 2 Th 2 Pyz]在固态和二甲基甲酰胺或二甲基亚砜溶液中的 NMR 研究证实，在固态和溶液中噻吩环是不等价的。EXAFS 结果表明，[(CN) 2 Th 2 Pyz(PdCl 2 ) 2 ]·H 2 O 中二(2-噻吩基)吡嗪基部分形成了两个不同的 Pd(II)配位位点，具有相同的 Pd-N(pyz)(2.03(3)Å)和 Pd-Cl(2.36(3)Å)键长，但不同的 Pd-S1(2.25(4)Å)和 Pd-S2(3.21(5)Å)键距在整体不对称的分子框架中。密度泛函理论(DFT)和时间相关 DFT(TDDFT)理论研究也提供了关于前体及其金属化 Pd(II)衍生物的结构和光谱行为的信息。还对两个杂五吡咯嗪卟嗪大环进行了(1)H/(13)C NMR 和紫外-可见光谱测量，这些大环是通过 PdCl 2 与[Th 8 TPyzPzM]反应制备的，其中 Th 8 TPyzPz = 四-2,3-[5,6-二(2-噻吩基)-吡嗪]卟嗪二阴离子，M = Mg(II)(H 2 O)或 Zn(II)。新合成的[(PdCl 2 ) 4 Th 8 TPyzPzM]化合物的光谱数据表明，PdCl 2 的结合涉及 S(2(th))PdCl 2 型配位位点，每个二(2-噻吩基)吡嗪片段的两个噻吩环以等效的方式与 Pd(II)配位("th-th"配位)。这与相应的八吡啶化类似物("py-py"配位)相同。