Ein molekularer Knoten mit zwölf Amidgruppen – Einstufensynthese, Kristallstruktur, Chiralität

Abstract

Molekulare Knoten sind eine noch wenig bekannte Substanzklasse. [1] Bisher konnten lediglich solche vom (historisch ersten) Phenanthrolin-(Dietrich-Buchecker und Sauvage, 1989), [2] Nucleinsäure- (Seeman, 1992) [3] und Krone/Quat-Typ (Stoddart et al., 1997) [4] synthetisiert werden. Wir berichten hier über die wohl einfachste, unter Selbstorganisation ablaufende Synthese eines neuartigen molekularen Kleeblattknotens in 20 % Ausbeute, der auûer einem 96-gliedrigen Die Einfachheit kovalent aufgebauter Modelle dieses Typs ermöglicht entsprechende Untersuchungen für die schnelle Charakterisierung neuer Metallkomplexe hinsichtlich ihrer Fähigkeit zur Funktionalisierung von C-H-Bindungen. Derzeit untersuchen wir Möglichkeiten zur vorhersagbaren Positionierung des Substrats am Metallzentrum durch nichtkovalente Wechselwirkungen, um so zu einer tatsächlich katalytisch aktiven oxidierenden Spezies zu gelangen.

Self-Assembly of Rings, Catenanes, and a Doubly Braided Catenane Containing Gold(I): The Hinge-Group Effect in Diacetylide Ligands

“…Yield: 4.38 g, 85 %; IR (Nujol): n Ä 2049 (br, w), 2121 cm À1 (s) (CC); 1 H NMR (300 MHz, CD 2 Cl 2 , 258C): d 7.21 (m, 4 H; C 6 H 4 ), 6.88 (m, 4 H; C 6 H 4 ), 4.66 (d, J 2. 4 Hz,4 H; OCH 2 ), 2.56 (t, J 2.4 Hz, 2 H; CCH), 2.24 (m, 4 H; C 6 H 10 ), 1.51 (m, 6 H; C 6 H 10 ); 13 C NMR (75 MHz, CD 2 Cl 2 , 258C): d 155. 5, 142.3, 128.3, 114.7 (all C 6 H 4 ), 79.2 (CCH), 75.4 (CCH), 56.1 (OCH 2 ), 45.…”

“…1 ± 2 mL) and addition of pentane (100 mL) precipitated a white solid. 4 PPh 2 ]}]´0.4 CH 2 Cl 2´0 .6 Et 2 O were grown from slow diffusion of diethyl ether into a solution of 4 a in dichloromethane. A colorless, trapezoidal plate was mounted on a glass fibre and data were collected at low temperature (150 K) by using a Nonius Kappa-CCD diffractometer with COLLECT (Nonius, 1998) software.…”

“…Compound 4 c: Crystals of [{m-H 2 C(C 6 H 4 OCH 2 CCAu) 2 }{m-[Ph 2 P-(CH 2 ) 4 PPh 2 ]}] 2´3 CH 2 Cl 2 were grown from slow diffusion of diethyl ether into a solution of 4 c in dichloromethane. A colorless, rectangular plate was mounted on a glass fibre.…”

“…[3±6] New synthetic strategies, based on ideas such as metal-ion templating [3] and selfassembly through non-covalent interactions, [4] have led to the realization of these original ideas through the synthesis of increasingly intricate molecular topologies. [5,6] These supermolecules attract continued attention for their potential application in the development of nanoscale devices.…”

Mass spectrometric evidence for catenanes and rotaxanes from negative-ESI FT-ICR tandem-MS-experiments

“…Some of them may be deprotonated at one of their amide bonds, others bear a phenolic OH group so that it should be Chart 1. Structures under study here involve a series of differently substituted tetralactam macrocycles (1-10), two catenanes (11 and 12), the trefoil amide knot 13, and five different rotaxanes (14)(15)(16)(17)(18). The axles 19-21 serve as control compounds.…”