Toward Dendrimers with Cylindrical Shape in Solution

The structures of seven benzene derivatives [1,2,3-tri(bromomethyl)benzene, (1); 3,5-di(bromomethyl)bromobenzene, (2); 2,5-di(bromomethyl)bromobenzene, (3); 4-(bromomethyl)-2,5-dibromotoluene, (4); 4-(bromomethyl)bromobenzene, (5); 2,3-di(bromomethyl)bromobenzene, (6) and (bromomethyl)-p-dibromobenzene, (7)] with bromo and bromomethyl (and in one case methyl) substituents are presented and analysed in terms of Br···Br interactions up to 4.0Å, supported by hydrogen bonds H···Br. Some interactions of the type Br···π and π···π are encountered and play a subordinate role in the packing. Despite the close chemical similarity of the compounds, some of which are isomers with permuted substituent positions, the packing motifs are highly variable. Compounds 2-5 are based on layer structures with Br n (n = 3, 4) and/or mixed Br/C rings. Compounds 1, 6 and 7 display three-dimensional packings of differing complexity, but with interpretable substructures; 1 can be analysed in terms of ribbons of linked Br 3 and Br 4 rings; 6 displays chains of linked Br 3 triangles; 7 consists of ribbons of linked Br 4 quadrilaterals.

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“…Spectroscopic data for compounds 1 [18], 2 [19], 3 [20], 4 [21], 5 [22,23], 6 [24,25], and 7 [26] agree with those reported in …”

Section: Methodssupporting

confidence: 84%

X-Ray Structure Determinations of Bromo- and/or Bromomethylsubstituted Benzenes: C–H···Br, C–Br···Br, and C–Br···π Interactions

Jones

Kuś

Dix

2012

Zeitschrift Für Naturforschung B

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“…140,141 The sterically demanding, perfectly branched dendritic side chains force the linear backbone of these polymers into an extended conformation and can lead to the formation of molecular objects in the nanometer range. 142,143 It remains an intriguing question, if LHGCs are also able to show this behavior and if they could be used for similar applications as DenPols, which range from biomedicine to catalysis. The major distinction of LHGCs compared with DenPols is their facile synthesis.…”

Section: Linear-hyperbranched Graft Copolymersmentioning

confidence: 99%

Hyperbranched aliphatic polyether polyols

Schömer

Schüll

Frey

2012

J. Polym. Sci. A Polym. Chem.

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Hyperbranched polymers, dendritic macromolecules with branch-on-branch structures, have become an important polymer class since the early 1990s. They combine several advantages of the perfectly branched dendrimers with easy accessibility, typically in a one-step synthesis. Hyperbranched polyethers are a particularly interesting class of chemically stable and often biocompatible materials. Multifunctional hyperbranched polyethers with controllable molar mass and comparably low polydispersities can been prepared using hydroxyl-functional epoxides or oxetanes for polymerization via anionic and cationic polymerization mechanisms. Here, we review the progress in the preparation, characterization, and application of these uniquely versatile aliphatic polyether polyols. Their unusual mechanical, thermal, and solution properties render them useful for a variety of applications, for example, as building blocks for various complex macromolecular architectures or in biomedical applications.

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“…Some of these macromolecules may be ceeded very cleanly and gave the corresponding carboxylic considered as molecular objects with a cylindrical acid 2b in 90% yield. shape [2] [3] . In order to be able to engineer the properties of this intriguing class of macromolecules [4] it would be imScheme 1.…”

Section: Introductionmentioning

confidence: 99%

Hydroxy-Functionalized Dendritic Building Blocks

et al. 1998

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A convenient and practical multi‐gram procedure for the synthesis of second‐ (G2; 4a, 5a, 5d) and third‐generation (G3; 6a) dendrons with orthogonally protected functional groups in the periphery (hydroxy) and at the focal point (carboxylic acid) is described. It uses the amply available first‐generation dendrons with amine and carboxylic ester functions (1) and tetrahydropyranyl‐protected hydroxy and carboxylic acid functions (2b, 3), respectively, which are connected via amides by peptide methods. Purification is either done by recrystallization or simple filtration through silica gel and yields the products as analytically pure materials on a several‐gram scale (even for G3). ‘The dendrons’ protective groups are proven to be orthogonal (500‐MHz NMR) which makes them useful components (building blocks) of a future dendron construction kit for a versatile synthesis of, for example, dendronized polymers.

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Toward Dendrimers with Cylindrical Shape in Solution

Cited by 219 publications

References 16 publications

X-Ray Structure Determinations of Bromo- and/or Bromomethylsubstituted Benzenes: C–H···Br, C–Br···Br, and C–Br···π Interactions

X-Ray Structure Determinations of Bromo- and/or Bromomethylsubstituted Benzenes: C–H···Br, C–Br···Br, and C–Br···π Interactions

Hyperbranched aliphatic polyether polyols

Hydroxy-Functionalized Dendritic Building Blocks

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