Willner H, Bodenbinder M, Bröchler R, Hwang G, Rettig S J, Trotter J, von Ahsen B, Westphal U, Jonas V, Thiel W, Aubke F
Contribution from the Fachbereich 6, Anorganische Chemie, Gerhard-Mercator-Universität GH Duisburg, Lotharstrasse 1, D-47048 Duisburg, Germany.
J Am Chem Soc. 2001 Jan 31;123(4):588-602. doi: 10.1021/ja002360s.
The salts [M(CO)(4)]Sb(2)F(11), M = Pd, Pt, are prepared by reductive carbonylation of Pd[Pd(SO(3)F)(6)], Pt(SO(3)F)(4) or PtF(6) in liquid SbF(5), or HF-SbF(5). The resulting moisture-sensitive, colorless solids are thermally stable up to 140 degrees C (M = Pd) or 200 degrees C (M = Pt). Their thermal decompositions are studied by differential scanning calorimetry (DSC). Single crystals of both salts are suitable for an X-ray diffraction study at 180 K. Both isostructural salts crystallize in the monoclinic space group P2(1)/c (No. 14). The unit cell volume of [Pt(CO)(4)]Sb(2)F(11) is smaller than that of [Pd(CO)(4)]Sb(2)F(11) by about 0.4%. The cations M(CO)(4), M = Pd, Pt, are square planar with only very slight angular and out-of-plane deviations from D(4)(h)() symmetry. The interatomic distances and bond angles for both cations are essentially identical. The Sb(2)F(11) anions in [M(CO)(4)]Sb(2)F(11) M = Pd, Pt, are not symmetry-related, and both pairs differ in their Sb-F-Sb bridge angles and their dihedral angles. There are in each salt four to five secondary interionic C- -F contacts per CO group. Of these, two contacts per CO group are significantly shorter than the sum of the van der Waals radii by 0.58 - 0.37 A. In addition, structural, and spectroscopic details of recently synthesized [Rh(CO)(4)][Al(2)Cl(7)] are reported. The cations Rh(CO)(4) and M(CO)(4), M = Pd, Pt, are characterized by IR and Raman spectroscopy. Of the 16 vibrational modes (13 observable, 3 inactive) 10 (Pd, Pt) or 9 (Rh), respectively, are found experimentally. The vibrational assignments are supported by DFT calculations, which provide in addition to band positions also intensities of IR bands and Raman signals as well as internal force constants for the cations. (13)C NMR measurements complete the characterization of the square planar metal carbonyl cations. The extensive characterization of [M(CO)(4)]Sb(2)F(11), M = Pd, Pt, reported here, allows a comparison to linear and octahedral [M(CO)(n)()]Sb(2)F(11) salts [M = Hg (n = 2); Fe, Ru, Os (n = 6)] and their derivatives, which permit a deeper understanding of M-CO bonding in the solid state for superelectrophilic cations with Sb(2)F(11) or SbF(6) as anions.
盐类[M(CO)(4)]Sb(2)F(11)，M = Pd、Pt，是通过在液态SbF(5)或HF - SbF(5)中对Pd[Pd(SO(3)F)(6)]、Pt(SO(3)F)(4)或PtF(6)进行还原羰基化反应制备的。所得对湿气敏感的无色固体在高达140℃（M = Pd）或200℃（M = Pt）时热稳定。通过差示扫描量热法（DSC）研究了它们的热分解。两种盐的单晶适用于在180 K下进行X射线衍射研究。两种同构盐均结晶于单斜空间群P2(1)/c（编号14）。[Pt(CO)(4)]Sb(2)F(11)的晶胞体积比[Pd(CO)(4)]Sb(2)F(11)的小约0.4%。阳离子M(CO)(4)，M = Pd、Pt，为平面正方形，与D(4)(h)对称性仅有非常轻微的角度和平面外偏差。两种阳离子的原子间距离和键角基本相同。[M(CO)(4)]Sb(2)F(11)，M = Pd、Pt中的Sb(2)F(11)阴离子不具有对称相关性，且两对阴离子在其Sb - F - Sb桥角和二面角上有所不同。每种盐中每个CO基团有四到五个次级离子间C - -F接触。其中，每个CO基团有两个接触明显短于范德华半径之和0.58 - 0.37 Å。此外，还报道了最近合成的[Rh(CO)(4)][Al(2)Cl(7)]的结构和光谱细节。阳离子Rh(CO)(4)和M(CO)(4)，M = Pd、Pt，通过红外光谱和拉曼光谱进行表征。在16种振动模式（13种可观测，3种非活性）中，分别实验发现10种（Pd、Pt）或9种（Rh）。振动归属得到密度泛函理论（DFT）计算的支持，DFT计算除了提供能带位置外，还提供红外谱带和拉曼信号的强度以及阳离子的内力常数。(13)C NMR测量完成了平面正方形金属羰基阳离子的表征。本文报道的[M(CO)(4)]Sb(2)F(11)，M = Pd、Pt的广泛表征，使得能够与线性和八面体的[M(CO)(n)()]Sb(2)F(11)盐类[M = Hg（n = 2）；Fe、Ru、Os（n = 6）]及其衍生物进行比较，这有助于更深入地理解以Sb(2)F(11)或SbF(6)为阴离子的超亲电阳离子在固态中的M - CO键合。
