Vergleichende Kernresonanz‐Untersuchungen an Makrocyclen und einem Catenan

Fritz, Hans; Logemann, Enno; Schill, Fottfried; Winkler, Tammo

doi:10.1002/cber.19761090407

Cited by 41 publications

(22 citation statements)

References 22 publications

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“…Similar shifts in 13 C NMR spectra have been observed in hydrocarbon catenanes relative to the individual macrocyclic components (6). These shifts to lower field were explained by interannular van der Waals interactions.…”

Section: A Nmr Resultssupporting

confidence: 55%

“…In 1 H NMR downfield shifts relative to the individual components have been observed in hydrocarbon catenane systems (6). It was reasoned that because of the interlocked structure the intertwined segments of the macrocycles can not be solvated in the same manner as the unthreaded macrocycle and this lack of solvation results in the downfield shift of the 1 H NMR signal.…”

Section: A Nmr Resultsmentioning

confidence: 98%

“…For example, the synthesis designed to produce 42-crown-14 (42C14) involves tri(ethylene glycol) ditosylate (2) addition to the sodium dianion (1) of tetra(ethylene glycol) in tetrahydrofuran (THF) (Scheme 1) to initially form α-oxy-ω-tosylate derivative 3, which can either cyclize to form 21-crown-7 (21C7) (4) or react with more 1 to produce the undeca(ethylene glycol) dianion (5). 3 can also react with 2 to form deca(ethylene glycol) ditosylate (6). After chain extension from the reaction of 2 and 5 or 1 and 6, the resultant oxytosylate 7 can afford 42C14 (8) through cyclization.…”

Section: Introductionmentioning

confidence: 99%

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42-crown-14-based [2]catenane

Gibson¹,

Lee²

2000

Can. J. Chem.

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A compound isolated from a synthesis directed toward 42-crown-14 (42C14) has been purified and characterized by means of IR, HPLC, NMR, MS, and DSC techniques. Its infrared spectrum contains no OH, tosylate, or unsaturated unit signals. The HPLC retention time of the compound differs from that of "42C14" and other crown ethers examined. The chemical shifts of the singlets in the 1 H and 13 C NMR spectra differ from those of poly(ethylene oxide)s (PEOs), and crown ethers. The FAB mass spectra contain signals attributable to a compound with twice the mass of 42C14 and the fragmentation pattern is consistent with [2]catenane 9 based on interlocked 42C14 units, because the next major signals generally correspond to 42C14 and its adducts. The DSC results showed that the compound, a colorless wax at room temperature, was amorphous with a glass transition temperature which was 80°higher than those of aliphatic crown ethers, which are crystalline compounds with melting points >40°C. Considering the high yield of the compound (8% in the reaction mixture as determined by NMR, 1.7% isolated), it is believed that sodium cation-crown ether-linear ether complexation was involved in templating its formation. Evidence for such complexation was also observed in the FAB MS.Résumé : Un composé a été isolé d'une synthèse effectuée dans le but d'obtenir l'éther 42-couronne-14 (42C14); on l'a purifié et caractérisé par des techniques de IR, CLHP, RMN, SM et d'analyse calorimétrique différentielle (ACD). Son spectre IR ne présente aucun signal correspondant à des groupes OH, tosylate ou insaturé. Le temps de rétention de ce composé en CLHP diffère de celui du « 42C14 » ou de tous les autres éthers couronnes étudiés. Les déplacements chimiques des singulets dans les spectres RMN du 1 H et du 13 C diffèrent de ceux des poly(oxydes d'éthylène) (POE) et des éthers couronnes. Les spectres de masse impliquant un bombardement avec des atomes rapides (BAR) comportent des signaux que l'on pourrait attribuer à un composé de masse double de celle du 42C14 et son patron de fragmentation est en accord avec le [2]caténane 9 dont la base serait des unités 42C14 reliées puisque les signaux majeurs suivants correspondent au 42C14 et à ses adduits. Les résultats d'ACD montrent que le composé, une cire incolore à la température ambiante, est amorphe avec une température de transition vitreuse qui est de 80°C plus élevée que celles des éthers couronnes aliphatiques qui sont des composés cristallins dont les points de fusion sont supérieurs à 40°C. Considérant le rendement élevé de ce composé (8% du mélange réactionnel sur la base de la RMN et 1,7% de produit isolé), on croit qu'une complexation du cation sodique avec l'éther couronne linéaire conduit à un gabarit impliqué dans sa formation. On a aussi observé des données pouvant supporter l'hypothèse d'une telle complexation dans le SM avec BAR.

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Section: A Nmr Resultssupporting

confidence: 55%

Section: A Nmr Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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42-crown-14-based [2]catenane

Gibson¹,

Lee²

2000

Can. J. Chem.

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“…These features are the reason why one would expect specific material properties of catenanes. [67] Even smaller shifts (0.00Ϫ0.03 ppm) were found between the spectra of the larger ring compounds m-13a, m-19e, m-19h, and l-13a and the corresponding catenanes m-18a, m-18e, m-18h, and l-18a. Having the catenanes at hand, we took a closer look at their properties to see whether they met our expectations.…”

Section: The Co-conformation Of the Catenanes 18mentioning

confidence: 88%

Non‐Rusty [2]Catenanes with Huge Rings and Their Polymers

Godt

2004

Eur J Org Chem

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We describe the design and synthetic realisation of [2]catenanes characterised by having huge rings that can rotate freely and shift laterally within the constraints of concatenation. The synthetic strategy, which is based on using a carbonate group as a covalent template and oxidative dimerization of alkynes to achieve ring formation, is versatile with respect to ring size and the presence of functional groups. The monocyclic constitutional isomer of the catenane is available by a simple exchange of steps in the sequence. EPR spectroscopy revealed that in solution the catenanes adopt all possible co‐conformations in equal abundances. The thermotropic liquid crystallinity of the [2]catenanes and their corresponding non‐intertwined macrocycles proves intermolecular ordering in the bulk phase. The [2]catenanes were polymerized through ester formation and through acyclic diene metathesis. All of the poly[2]catenanes have rather low degrees of polymerisation ( ≈︁ 10), possibly because cyclisation occurs. For the preparation of [n]catenanes having n > 3, we propose fusing the rings of [2]catenanes so that the crucial steps of threading and cyclisation need only occur during the synthesis of the smallest catenane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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“…[6]- [12] and [14], we can allot the partial molar volumes for any atomic groups. slopes of the straight lines in eqs.…”

Section: For Cycloalkanes We Havementioning

confidence: 99%

Additivity of the partial molar volumes of organic compounds

Nishimura¹,

Tanaka²,

Motoyama³

1987

Can. J. Chem.

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N o~i o NISH~MURA, TOHRU TANAKA, and TAKUSH~ MOTOYAMA. Can. J. Chem. 65, 2248Chem. 65, (1987. A critical test of additivity for partial molar volume has been made at 25' C in CCI4 with polyethylene glycol dimethyl ethers, crown ethers, cycloalkanes, n-alkanes, and others. Plots of partial molar volume at infinite dilution (v O ) against the properly chosen number of repeating unit ( n ) are linear except for small cyclic molecules, and the slopes of homologous straight chain and ring compounds are the same. The values of v O extrapolated to 11 = 0 for cycloalkanes and crown ethers support the validity of the contribution due to the translational kinetic energy that has been predicted recently on a theoretical basis. The importance of packing efficiencies around the solute molecules has been examined by means of simple models.NORIO NISHIMURA, TOHRU TANAKA et TAKUSH~ MOTOYAMA. Can. J. Chem. 65,2248Chem. 65, (1987. OpCrant i 25"C, dans des solutions de CC14, on a effectuC une Cvaluation critique de I'additivitC des volumes molaires partiels pour des Cthers dimtthyliques du polyCthylkne glycol, des Cthers couronnes, des cycloalcanes, des n-alcanes et d'autres composCs. A l'exception des molCcules contenant des petits cycles, on a trouvC qu'il existe une relation linCaire entre les volumes molaires partiels i dilution infinie (a O) et le nombre choisi appropriC d'unitts periodiques (n); de plus, les pentes des courbes pour les composCs homologues aliphatiques sont les mkmes que celles pour les composts cycliques. Pour les cycloalcanes et pour les Cthers couronnes, les valeurs de (v O ) extrapolCes i n = 0 sont en accord avec la prCdiction qui a rCcemment CtC faite sur une base thCorique et selon laquelle on pr6voit une contribution de la part de 1'Cnergie cinCtique de translation. Utilisant des moddes simples, on a CtudiC I'importance des efficacitCs d'empilement autour des moltcules de solutCs.[Traduit par la revue]

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Vergleichende Kernresonanz‐Untersuchungen an Makrocyclen und einem Catenan

Cited by 41 publications

References 22 publications

42-crown-14-based [2]catenane

42-crown-14-based [2]catenane

Non‐Rusty [2]Catenanes with Huge Rings and Their Polymers

Additivity of the partial molar volumes of organic compounds

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