X-ray Diffraction and DOSY NMR Characterization of Self-Assembled Supramolecular Metallocyclic Species in Solution

• Published in: Journal of the American Chemical Society Vol. 127; no. 30; pp. 10731 - 10738
• Main Authors: Megyes, Tünde, Jude, Hershel, Grósz, Tamás, Bakó, Imre, Radnai, Tamás, Tárkányi, Gábor, Pálinkás, Gábor, Stang, Peter J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03-08-2005
• Subjects: Chemistry; Exact sciences and technology; Magnetic Resonance Spectroscopy - methods; Models, Molecular; Organic chemistry; Organometalloidal and organometallic compounds; Organoplatinum Compounds - chemistry; Platinum - chemistry; Preparations and properties; Solutions; Transition metals derivatives; X-Ray Diffraction - methods; Cationic complex; Hydrodynamic radius; Tertiary phosphine; Platinum Organic compounds; Organic ligand; NMR spectrometry; Transition metal Complexes; X ray diffraction; Organic synthesis; Complexes Mixed; Supramolecular structure; Polynuclear complex; Diffusion coefficient; Physicochemical properties
• DOI: 10.1021/ja0523690
• EISSN: 1520-5126
• ISSN: 0002-7863

Wide-angle X-ray scattering and diffusion NMR techniques have been used to obtain structural information on three self-assembled metallacyclic supramolecular complexes in solution:  a rectangle, a triangle, and a three-diminsional cage. The low-angle region of the measured diffraction patterns and hydrodynamic radii calculations, determined from DOSY NMR experiments, suggest that the supramolecular assemblies retain their shape when dissolved in nitromethane. The experimental structure functions for the large-angle region have been analyzed, and the intramolecular contributions of the platinum−platinum interactions are discussed. These scattering measurements provide evidence that the supramolecular assemblies are not as rigid in solution as they are in the single crystal. Finally, by analysis of the radial distribution functions of the solutions, direct structural information (e.g., platinum−platinum intramolecular distances and coordination number) about the supramolecular assemblies has been obtained.