Synthesis and Characterization of a Rhenabenzyne Complex

Abstract

Komplexe Umlagerungen: Rhenahydrobenzole sind mit Metallabenzolen verwandte Metallaarene (siehe Schema) und werden durch Umlagerung aus einem thermisch instabilen Rhenium‐Carbin‐Komplex erzeugt. Die Rhenahydrobenzol‐Komplexe wurden durch Elementaranalyse, 1H‐NMR‐Spektroskopie und Röntgenstrukturanalyse charakterisiert. Die Ergebnisse zeigen, dass es möglich ist, Metallahydrobenzole mit verschiedenen Übergangsmetallzentren aufzubauen.

Synthesis and Characterization of a Metallapyridyne Complex

“…The bond distances of the CC bonds in the metallacycle rings of 4 (1.338(5)–1.456(5) Å) are within the range of typical aromatic CC bond lengths. The evident long/short CC bond alternations are parallel to those found in other metallabenzynes, such as osmabenzyne Os(CC(SiMe 3 )C(CH 3 )‐C(NO 2 )CH)(PPh 3 ) 2 Cl 2 [1.366(4)–1.440(4) Å],6a osmabenzyne Os(CC(SiMe 3 )C(CH 3 )C(NO)CH)(PPh 3 ) 2 Cl 2 [1.363(5)–1.451(5) Å],6a and rhenabenzyne Re(CCHC( t Bu)CHCH)‐(PMe 2 Ph) 3 Cl [1.367(6)–1.457(6) Å] 6b. The structural parameters indicate that the metallacycles of 4 could be represented by two resonance structures, namely 4 and 4 A , with 4 A being more important [Eq.…”

A Metal‐Bridged Tricyclic Aromatic System: Synthesis of Osmium Polycyclic Aromatic Complexes

“…[2] Many metalla-aromatics have been synthesized since that time. [4][5][6][7] In contrast, the metal-bridged bicyclic aromatics, which contain a metal that is shared by two aromatic rings (type II, Scheme 1), have been less developed. [4][5][6][7] In contrast, the metal-bridged bicyclic aromatics, which contain a metal that is shared by two aromatic rings (type II, Scheme 1), have been less developed.…”

“…[3] Most of the well-characterized metalla-aromatic systems contain five-or six-membered rings with the characteristic feature that the metal participates only in one ring system (type I, Scheme 1). [4][5][6][7] In contrast, the metal-bridged bicyclic aromatics, which contain a metal that is shared by two aromatic rings (type II, Scheme 1), have been less developed. [7g, 8] Metal-bridged bicyclic aromatics are interesting because the bridge-head metal can stabilize and influence both rings, thus creating metalla-aromaticity in an extended, p-electron conjugated framework.…”

Synthesis of Five‐Membered Osmacycloallenes and Conversion into Six‐Membered Osmacycloallenes

“…For comparison, the angles for the cumulative double bonds in the five-membered metallacycloallenoids range from 153.6(3)8 to 158.7(2)8 in II [5] and from 145.8(5)8 to 153.5(4)8 in III. [6] Strained five-or six-membered metallacycloalkynes, such as metallacyclopen-tynes, [11] metallapentalyne, [12] metallabenzynes, [13] and metallapyridyne, [14] display distorted angles at the carbyne carbon, which can be represented by resonance structures of metallacycloallenes.…”