64793-98-2Relevant academic research and scientific papers
Synthesis of organometallic poly(dendrimer)s by macromonomer polymerization: effect of dendrimer size and structural rigidity on the polymerization efficiency
Cheung, Siu-Yin,Chow, Hak-Fun,Ngai, To,Wei, Xiaoling
supporting information; experimental part, p. 2278 - 2288 (2009/10/23)
Two series of first to third generation (G1-G3) oligoether dendrimers, one hearing a shorter spacer chain (C-O) and the other having a longer spacer branch (C-C-C-O) were prepared. Both series of compounds, containing two reactive C≡CH moieties on the dendrimer surface, were used as macromonomers and copolymerized with trans-[Pt(PEt3)2Cl2] to form organometallic poly(dendrimer)s by an outer-sphere-outer-sphere connection strategy. It was found that concentration of monomer used in the polymerization, the dendrimer generation, and, most strikingly, the length of the spacer were key factors that determined the polymerization efficiency. Hence, the structurally more rigid and compact C-O linked dendrimers formed poly(dendrimer)s with a higher degree of polymerization than the structurally less rigid and more bulky C-C-C-O dendrimers. This result was due to the higher tendency to form cyclic oligomers in the latter series of compounds. In addition, the differences in the polymerization efficiency among the three generations of dendrimers could be explained by the gradual decrease of reactive functional group density on the dendrimer surface.
Synthesis and retrostructural analysis of libraries of AB3 and constitutional isomeric AB2 phenylpropyl ether-based supramolecular dendrimers
Percec, Virgil,Peterca, Mihai,Sienkowska, Monika J.,Ilies, Marc A.,Aqad, Emad,Smidrkal, Jan,Heiney, Paul A.
, p. 3324 - 3334 (2007/10/03)
We report the synthesis of methyl esters of 3-(4-hydroxyphenyl)propionic, 3-(3,4-dihydroxyphenyl)propionic, 3-(3,5-dihydroxyphenyl)propionic, and 3-(3,4,5-trihydroxyphenyl)propionic acids and their use in a convergent iterative strategy to prepare up to four generations of three libraries, one of 3,4,5- and two of constitutional isomeric 3,4- and 3,5-substituted 3-phenylpropyl dendrons. Each library contains 3-[3,4,5-tris(dodecyl-1-oxy) phenyl]propyl-, 3-[3,4-bis(dodecyl-1-oxy)phenyl]propyl-, 3-{3,4-bis[3-(4- dodecyl-1-oxyphenyl)propyl-1-oxy]phenyl}propyl-, and 3-{3,4,5-tris[3-(4-dodecyl- 1-oxyphenyl)propyl-1-oxy]phenyl}propyl ether first-generation dendrons on their periphery and -CO2CH3, -COOH, and -CH2OH groups at their apex. Regardless of their generation number and their periphery, internal, and apex structures, these dendrons self-assemble into supramolecular dendrimers that self-organize into all periodic and quasi-periodic assemblies encountered previously and in several unencountered with architecturally related benzyl ether-based supramolecular dendrimers. A variety of porous columnar lattices that were previously obtained only from dendritic dipeptides and hollow supramolecular spheres were also discovered from these building blocks. The more flexible and less compact 3-phenylpropyl ether repeat units are stable under acidic conditions, facilitate a simpler synthetic strategy, provide faster dynamics of self-assembly into higher-order supramolecular structures of larger dimensions, exhibit lower transition temperatures than the corresponding benzyl ether homologues, and demonstrate the generality of the self-assembly concept based on amphiphilic dendrons.
Synthesis of hormothamnione and 6-desmethoxyhormothamnione
Jain, Niveta,Gambhir, Geetu,Krishnamurty
, p. 278 - 283 (2007/10/03)
The antineoplastic styrylchromones hormothamnione 1 and 6-desmethoxyhormothamnione 2 are readily prepared by selective and simultaneous demethylation and debenzylation of chromones 3 and 4 using excess AlCl3-Nal in CH3CN.
