Intermolecular (119)Sn,(31)P Through-Space Spin-Spin Coupling in a Solid Bivalent Tin Phosphido Complex

• Published in: Inorganic chemistry 2016-05, Vol.55 (9), p.4669-4675
• Main Authors: Arras, Janet, Eichele, Klaus, Maryasin, Boris, Schubert, Hartmut, Ochsenfeld, Christian, Wesemann, Lars
• Format: Article
• Language: English
• ISSN: 1520-510X
• DOI: 10.1021/acs.inorgchem.6b00573

A bivalent tin complex [Sn(NP)2] (NP = [(2-Me2NC6H4)P(C6H5)](-)) was prepared and characterized by X-ray diffraction and solution and solid-state nuclear magnetic resonance (NMR) spectroscopy. In agreement with the X-ray structures of two polymorphs of the molecule, (31)P and (119)Sn CP/MAS NMR spectra revealed one crystallographic phosphorus and tin site with through-bond (1)J((117/119)Sn,(31)P) and through-space (TS)J((117/119)Sn,(31)P) spin-spin couplings. Density functional theory (DFT) calculations of the NMR parameters confirm the experimental data. The observation of through-space (TS)J((117/119)Sn,(31)P) couplings was unexpected, as the distances of the phosphorus atoms of one molecule and the tin atom of the neighboring molecule (>4.6 Å) are outside the sum of the van der Waals radii of the atoms P and Sn (4.32 Å). The intermolecular Sn···P separations are clearly too large for bonding interactions, as supported by a natural bond orbital (NBO) analysis.