Self-complementary nickel halides enable multifaceted comparisons of intermolecular halogen bonds: fluoride ligands vs. other halides.
Self-complementary nickel halides enable multifaceted comparisons of intermolecular halogen bonds: fluoride ligands vs. other halides.
复制标题
DOI：
10.1039/c8sc00890f
复制
发表时间：
2018-04-21
期刊：
影响因子：
8.4
通讯作者：
Perutz RN
中科院分区：
文献类型：
--
作者：
Thangavadivale V;Aguiar PM;Jasim NA;Pike SJ;Smith DA;Whitwood AC;Brammer L;Perutz RN
X-Ni-C6 F4 I···X-Ni-C6 F4 I卤素键网络的研究揭示了氟化物（X = F）与其他卤化物之间的显著差异：19 F-MAS NMR光谱是卤素键的灵敏探针。本文报道了三个系列的具有自互补基序的配合物的合成，并对四个卤代配体C_6F_4I···X-Ni（X = F，Cl，Br，I）之间的卤素键进行了结构比较。在反式-[NiX（2，3，5，6-C6 F4 I）（PEt 3）2] 1 pX和反式-[NiX（2，3，4，5-C6 F4 I）（PEt 3）2]（X = F，Cl，Br，I）1 oX系列中，苯环上的碘取代基分别位于金属的帕拉和邻位。膦取代基的系列变化，trans-NiX（2，3，5，6-C6 F4 I）（PEt 2 Ph）2]（X = F，I）2 pX。获得了完整系列1 pX、1 oF、1 oCl、1 oI和2 pI的晶体结构。所有配合物在固态下均表现出卤键，其中1 pF表现出独特的线性链特征，最短的卤键d（C6 F4 I···F-Ni）= 2.655（5）π，卤键距离（I···F）与Bondi货车van der Waals半径之和相比最大减小23%.剩余的配合物形成锯齿形链的卤键的距离也减少相对于货车德瓦耳斯半径的总和。减少的幅度遵循模式F > Cl <$Br > I，1 pX> 1 oX，与遵循相同顺序的卤素键强度一致。I···X-Ni角的变化与卤化物配体的各向异性电荷分布一致。1 pF的X射线结构的温度依赖性表明，从240到111 K冷却时，卤键距离减少了0.055（7）π。三个多晶型的1 oI的比较表明，卤素键的几何形状可能会改变显着的结晶环境。通过比较1 pF和1 oF与不能形成卤键的配合物trans-NiF（C6 F5）（PEt 3）2] 3F的魔角旋转NMR谱，证明了卤键对固态19 F NMR化学位移的影响。卤素键导致垂直于镍配位面的张量分量中δiso的去屏蔽。结果表明氟配体在超分子结构中形成卤键的潜力。
Studies of X–Ni–C6F4I···X–Ni–C6F4I halogen-bonded networks reveal pronounced differences between fluoride (X = F) and other halides: the 19F-MAS NMR spectrum is a sensitive probe of the halogen bond. The syntheses of three series of complexes designed with self-complementary motifs for formation of halogen bonds between an iodotetrafluorophenyl ligand and a halide ligand at square-planar nickel are reported, allowing structural comparisons of halogen bonding between all four halides C6F4I···X–Ni (X = F, Cl, Br, I). In the series trans-[NiX(2,3,5,6-C6F4I)(PEt3)2] 1pX and trans-[NiX(2,3,4,5-C6F4I)(PEt3)2] (X = F, Cl, Br, I) 1oX, the iodine substituent on the benzene ring was positioned para and ortho to the metal, respectively. The phosphine substituents were varied in the series, trans-[NiX(2,3,5,6-C6F4I)(PEt2Ph)2] (X = F, I) 2pX. Crystal structures were obtained for the complete series 1pX, and for 1oF, 1oCl, 1oI and 2pI. All these complexes exhibited halogen bonds in the solid state, of which 1pF exhibited unique characteristics with a linear chain, the shortest halogen bond d(C6F4I···F–Ni) = 2.655(5) Å and the greatest reduction in halogen bond distance (I···F) compared to the sum of the Bondi van der Waals radii, 23%. The remaining complexes form zig-zag chains of halogen bonds with distances also reduced with respect to the sum of the van der Waals radii. The magnitude of the reductions follow the pattern F > Cl ∼ Br > I, 1pX > 1oX, consistent with the halogen bond strength following the same order. The variation in the I···X–Ni angles is consistent with the anisotropic charge distribution of the halide ligand. The temperature dependence of the X-ray structure of 1pF revealed a reduction in halogen bond distance of 0.055(7) Å on cooling from 240 to 111 K. Comparison of three polymorphs of 1oI shows that the halogen bond geometry may be altered significantly by the crystalline environment. The effect of the halogen bond on the 19F NMR chemical shift in the solid state is demonstrated by comparison of the magic-angle spinning NMR spectra of 1pF and 1oF with that of a complex incapable of halogen bond formation, trans-[NiF(C6F5)(PEt3)2] 3F. Halogen bonding causes deshielding of δiso in the component of the tensor perpendicular to the nickel coordination plane. The results demonstrate the potential of fluoride ligands for formation of halogen bonds in supramolecular structures.
登录
查看更多内容
影响因子：
62.1
作者：
Cavallo G;Metrangolo P;Milani R;Pilati T;Priimagi A;Resnati G;Terraneo G
通讯作者：
Terraneo G
影响因子：
15
作者：
Clot, Eric;Megret, Claire;Perutz, Robin N.
通讯作者：
Perutz, Robin N.
影响因子：
3.8
作者：
Brammer, L;Bruton, EA;Sherwood, P
通讯作者：
Sherwood, P
影响因子：
2.8
作者：
BENNETT, MA;WENGER, E
通讯作者：
WENGER, E
影响因子：
--
作者：
BONDI, A
通讯作者：
BONDI, A