Substituted Cyclooctatetraenes as Ligands inf-Metal Chemistry

Abstract

The use of substituted cyclooctatetraenes confers various desired properties on the resulting metal complexes such as a higher thermal and kinetic stability as well as higher solubility relative to the nonsubstituted systems. Furthermore, the formation of polymeric structures is inhibited because intermolecular interactions are reduced. Alkyl-and aryl-substituted cyclooctatetraenes were mainly used as ligands in the [a] a Karl-Winnacker-Stipendium. His current research interest revolves around the use of coordination compounds of the lanthanides for catalytic applications and for material science.MICROREVIEWS: This feature introduces the readers to the authors' research through a concise overview of the selected topic. Reference to important work from others in the field is included.

Cyclooctatetraenes through Valence Isomerization of Cubanes: Scope and Limitations

“…Since the discovery of 1,3,5,7‐cyclooctatetraene (COT, 1 ) in 1911 by the German Nobel laureate Willstätter and his co‐worker Waser, COT and its derivatives have found increasing application in diverse areas of synthetic chemistry . Some important examples include the total synthesis of natural products (e.g., pentacycloanammoxic acid ( 2 ) by Corey and Mascitti), use in organometallic chemistry (e.g., as a versatile ligand either in its neutral or anionic form such as the bis‐COT palladium sandwich complex 3 ), materials chemistry (e.g., 4 as a useful OLED emitter of blue light), in polymer chemistry as a swelling agent and more recently to access the archetypal fluxional hydrocarbon bullvalene on a practical scale . Beyond these broad applications, our group recently identified COT as a (bio)motif (i.e., bioactive complement to cubane (bio)isosterism), which enhanced biological activity in select pharmaceutical templates, for example, the warfarin analogue 5 (Scheme ).…”

It's not just the size that matters: crystal engineering of lanthanide-based coordination polymers

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Nevertheless, few fundamental structural motifs have been established, reecting the limited number of successful complete structural characterization studies. 17 The reason for this is the low solubility of the unsubstituted Cot ligand and its complexes in common organic solvents, which complicates the crystallization of these compounds as well as further investigations regarding their physical properties and reactivities. 2 The classical anionic sandwich complexes of the general type [K(L) n ][Ln III (h 8 -Cot) 2 ] (L = thf (n = 3), L = 18-crown-6 (n = 1), L = diglyme (n = 1)) were among the rst sandwich compounds of the lanthanides to be isolated.…”

Accurate Crystal Structures of C12H9CN, C12H8(CN)2, and C16H11CN Valence Isomers Using Nonspherical Atomic Scattering Factors

“…Cyclooctatetraenes (COTs) are antiaromatic [8]-annulenes with a distinctly nonplanar geometry, which see a great deal of use in coordination chemistry as sterically demanding ligands. , There has been strong directed research in recent years toward geometric modifications of polycyclic arenes to modulate electronic and optical properties that arise from three-dimensional nanocarbon structures. − COTs are an essential component to introducing stable and rational curvature into polycyclic sheets due to their tub-shaped geometry, and to this end, there has been significant inquiry as to how to incorporate COTs into these systems. In pursuit of this goal, Bello-Garcia et al.…”