Structures, Thermal Properties, and Reactivities of Cationic Rh–cod Complexes in Solid State (cod = 1,5-Cyclooctadiene)

Abstract

Cationic rhodium complexes with 1,5-cyclooctadiene (cod) ligands are important organometallic compounds that are useful as precatalysts; however, their solidstate structures and thermal properties have not been adequately investigated. In this study, we synthesized [Rh(cod)L]X (L = cod, C 6 H 6 , PhMe; X = SbF 6 , (FSO 2 ) 2 N (= FSA), CF 3 BF 3 , CB 11 H 12 ) and investigated their phase behaviors, crystal structures, and reactivities. The phase transitions of these salts result in disordered solid-state structures. Moreover, the structural disorder increases with a decrease in the cation symmetry in the SbF 6 salts; [Rh(cod)(PhMe)]SbF 6 exhibits a rotator phase, and the cations in other salts exhibit a dynamic rotational disorder. In contrast, a lower crystal symmetry with less cation disorder is observed for FSA salts. The thermal stabilities and reactivities of these salts were further investigated. FSA salts with arene ligands produce anion-coordinated complexes upon melting, and SbF 6 salts with arene ligands produce [Rh(cod)L′ 2 ]SbF 6 (L′ = MeCN and SMe 2 ) via an in situ single-crystal-to-single-crystal ligand-exchange reaction.

Catalytic activity of cyclobutadiene rhodium complexes in hydrosilylation and other transformations of alkynes

“…The complex [Rh(cod)( p -xylene)]SbF 6 was synthesized similarly to the literature procedure. 28 Column chromatography was carried out using Macherey–Nagel silica gel 60 (0.04–0.063 mm particle size).…”

Efficient Exploration of Highly Conductive Pyrrolidinium-based Ionic Plastic Crystals Using Materials Informatics

“…The solvent was then concentrated using an evaporator, and diethyl ether (200 mL) was added into the concentrated solution. The precipitated white solid was collected by suction filtration and dried under a reduced pressure for overnight to give (4.25 g, 82% yield) a gray solid, AgCF3BF3 43 .…”

Organometallic Ionic Liquids Containing Sandwich Complexes: Molecular Design, Physical Properties, and Chemical Reactivities

“…Rh-containing ILs 6 are orange diamagnetic liquids, and they are thermodynamically unstable because they gradually transform into an anioncoordinated complex. [12] Dinuclear ILs 7 are deep-green, mixed-valence liquids whose melting points are close to room temperature despite their high molecular weight. [13] ILs containing half-sandwich complexes, such as ILs 8-10, are generally highly viscous, colored liquids.…”

“…However, introduction of coordinating substituents into ILs 5 makes them photoreactive, which is a versatile feature to design photoreactive ILs (Section 5). Rh‐containing ILs 6 are orange diamagnetic liquids, and they are thermodynamically unstable because they gradually transform into an anion‐coordinated complex [12] . Dinuclear ILs 7 are deep‐green, mixed‐valence liquids whose melting points are close to room temperature despite their high molecular weight [13] .…”