New discrete metallocycles incorporating palladium(II) and platinum(II) corners and dipyridyldibenzotetraaza[14]annulene side units
New discrete metallocycles incorporating palladium(II) and platinum(II) corners and dipyridyldibenzotetraaza[14]annulene side units
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DOI：
10.1039/b510860h
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发表时间：
2006-02-07
影响因子：
4
通讯作者：
Wei, G
中科院分区：
文献类型：
--
作者：
Beves, JE;Chapman, BE;Wei, G
扩展的完全共轭大环联吡啶二苯并四氮杂[14]轮烯 (1) 与方形平面钯 (II) 和铂 (II) 配合物 [M(dppp)(三氟甲磺酸酯)(2)]中心点 2H(2)O (M = Pd, Pt) 的相互作用已在溶液和固态下进行了研究。在每种情况下均获得显示金属络合物:1比例为1:1的固体产物。 1和[Pd(dppp)(2)(三氟甲磺酸酯)(2)]中心点2H(2)O在二氯甲烷中的1:1混合物产生两种主要产物，如反应溶液的P-31 {H-1}-NMR谱中存在两个单峰所证明的。类似地，在将1:1产物溶解在硝基苯中所获得的相应光谱中，两个单峰是明显的。光谱的温度和浓度依赖性清楚地表明每种情况下存在的两种物质处于平衡状态。根据温度依赖性，低场信号被分配给两个物种中较小的一个。对于相应的含铂系统，观察到了大致平行的行为。铂衍生物的MS-ESI谱显示存在对应于[Pt(dppp)(1)](2)(2+)的双核物质，并且该产物的X射线结构证实相应的双核配合物以固态存在。该产品的几何形状是两个弯曲的大环侧单元桥接两个金属中心以产生椭圆形结构。尝试使用脉冲场梯度自旋回波 (PGSE) P-31 NMR 证实，低场共振对应于溶液中两种物质中较小的一种。含钯和铂产品的 STM (HOPG) 成像显示，阵列似乎由“拉链状”的二聚体单元行组成，后者的尺寸与 [Pt(dppp)(1)](2)(2+) 的 X 射线结构中发现的尺寸相当。
The interaction of the extended, fully-conjugated macrocycle, dipyridyldibenzotetraaza[14]annulene (1), with the square planar palladium(II) and platinum(II) complexes [M(dppp)(triflate)(2)]center dot 2H(2)O (M = Pd, Pt) has been investigated in both solution and the solid state. In each case solid products showing a 1 : 1 ratio of metal complex: 1 were obtained. A 1 : 1 mixture of 1 and [Pd(dppp)(2)(triflate)(2)]center dot 2H(2)O in dichloromethane yielded two major products as evidenced by the presence of two singlets in the P-31 {H-1}-NMR spectrum of the reaction solution. Similarly, two singlets were evident in the corresponding spectrum obtained on dissolving the 1 : 1 product in nitrobenzene. The temperature and concentration dependence of the spectra clearly showed that the two species present in each case were in equilibrium. From the temperature dependence, the low field signal was assigned to the smaller of the two species. Broadly parallel behaviour was observed for the corresponding platinum-containing system. The MS-ESI spectrum of the platinum derivative showed the presence of a dinuclear species corresponding to [Pt(dppp)(1)](2)(2+) and an X-ray structure of this product confirmed that a corresponding dinuclear complex exists in the solid state. This product has a geometry in which two curved macrocyclic side units bridge two metal centres to yield an ellipse-shaped structure. Attempts to employ pulsed-field gradient spin-echo (PGSE) P-31 NMR confirmed that the lower-field resonance corresponded to the smaller of the two species in solution. STM (HOPG) imaging of the palladium- and platinum-containing products revealed arrays that appear to be composed of "zipper-like" rows of dimer units, with the dimensions of the latter comparing well with those found in the X-ray structure of [Pt(dppp)(1)](2)(2+).