Tri‐, Penta‐, and Octaiodide Salts of Transition Metal Polyether Complexes

Abstract

Salts of transition metal cations complexed by 12-crown-4, benzo-15-crown-5 or 18-crown-6 with I 3 Ϫ , I 5 Ϫ and I 8 2Ϫ anions, are synthesized and their crystal structures are determined by single X-ray diffraction. The crystal structures of 1, 2 and 3 are built up by three different cations with the compositions [Fe(H 2 O) 6 (12c4) 6 ] 2ϩ , [Zn(H 2 O) 2 (b15c5) 3 ] 2ϩ , [Zn(H 2 O) 5 (18c6) 2 ] 2ϩ , and isolated triiodide anions I 3 Ϫ , respectively. Aside from the Einleitung Polyiodidanionen I 2mϩn nϪ mit wechselndem Iodüberschuss (m ϭ 1, I 3 Ϫ ; m ϭ 2, I 5 Ϫ , m ϭ 3, I 8 2Ϫ ) und verschiedenen Ionenladungen n lassen sich durch systematische Änderung der Form, Größe und Ladung des jeweiligen Gegenkations als kristalline Festkörper gewinnen, bisher allerdings nur ungeplant. Die Polyiodidanionen ergeben sich durch Addition von m Iodmolekülen und n Iodidionen und können isoliert oder mit unterschiedlicher Koordinationszahl und Dimensionalität verkettet oder vernetzt sein [1]. Die an zahlreichen Beispielen untersuchte Strukturchemie der Polyiodidanionen ist dabei gekennzeichnet durch Abstände, die den Bereich zwischen kovalenten (270 pm) und van der Waals-Kontakten (430 pm) umfassen. Über die Ursache dieser unterschiedlichen Abstände ist bisher allerdings nur wenig bekannt. Als Weiterführung unserer Arbeiten an Polyiodidanionen mit komplexen Kationen der allgemeinen Form [M(Kronenether)] xϩ (M ϭ Kationen der ersten und zweiten Hauptgruppe, Selten-Erdmetall-Kationen; Kronenether ϭ * Dr. I. Pantenburg

Combined EXAFS and DFT Structure Calculations Provide Structural Insights into the 1:1 Multi‐Histidine Complexes of CuII, CuI, and ZnII with the Tandem Octarepeats of the Mammalian Prion Protein

“…Regarding the solvated structure of aquozinc(II), there are countless examples of six‐coordinate [Zn II (OH 2 ) 6 ] 2+ in the Cambridge Structure Database, providing ample support for our assertion that this is a reasonable representation of Zn in aqueous solution. There are few examples of pentaaquozinc(II) species in the CSD, with the entries DEHFUR49 and YUPKAW50 representing credible bona fide [Zn II (OH 2 ) 5 ] 2+ species. Many other apparent pentaaquozinc(II) species that arise through structure and formula searches actually prove to be the result of disorder within the crystal, as evidenced by the presence of additional atoms within the Zn coordination sphere and apparently distorted coordination geometries (e.g., ASACON51 and FURWUL52).…”

Solid state anion–π interactions involving polyhalides

“…Finally, following the work of Metrangolo and Resnati et al 17 salt 5 was synthesized and mixed with iodine in methanolic solution (Scheme 1, Route 3). Compounds 2c, 3, 4, 5 and 6 are fully characterized by standard analytical methods ( 1 H, 19 F NMR, MS, IR, CHN). In order to investigate the polyiodides in detail without single crystals UV-Vis spectral as well as collision induced dissociation (CID) ESI mass spectrometric experiments were performed for 4a and 4b in solution.…”

“…Therefore, two mole- ), like recently reported for three structures. 19,20 The two Scheme 1 Routes to polyhalide salts. Crystals of compound 6 could be obtained by slow evaporation of methanol.…”

“…1 H-NMR (300 MHz, DMSO-d 6 ): δ ( ppm) = 4.57 (s, 4H, H benzyl ), 3.38 (t, J = 7.3 MHz, 6H, CH 2 ), 3.01 (t, J = 7.3 MHz, 6H, CH 2 ). 19…”

“…1 H-NMR (300 MHz, DMSO-d 6 ): δ ( ppm) = 4.82 (s, 4H, H benzyl ), 4.24 (s, 4H, CH 2 ), 3.13 (s, 12H, CH 3 ). 19…”