Phenylacetylene Dendrimers by the Divergent, Convergent, and Double-Stage Convergent Methods

Xu, Zhen; Kahr, Michael S.; Walker, Kathleen L.; Wilkins, Charles L.; Moore, Jeffrey S.

doi:10.1021/ja00090a002

Cited by 240 publications

(117 citation statements)

References 0 publications

Supporting

Mentioning

113

Contrasting

Unclassified

Order By: Relevance

“…[8][9][10][11][12][13] Since they can be prepared with high regularity and controlled molecular weights, 14 dendrimers offer great promise in the control of energy funneling. Their successful directional-energy transfer has been studied by Moore et al, 15,16,9,17 who have reported the syntheses of a peryleneterminated dendrimer, called the nanostar. This molecule presents four generations of linear PPE segments with decreasing lengths toward the periphery, creating an efficient energy funnel toward the perylene trap.…”

Section: Introductionmentioning

confidence: 99%

Nonadiabatic Molecular Dynamics Simulations of the Energy Transfer between Building Blocks in a Phenylene Ethynylene Dendrimer

et al. 2009

View full text Add to dashboard Cite

The ultrafast dynamics of electronic and vibrational energy transfer between two-and three-ring linear poly(phenylene ethynylene) units linked by meta-substitution is studied by nonadiabatic molecular dynamics simulations. The molecular dynamics with quantum transitions 1,2 method is used including an "on the fly" calculation of the potential energy surfaces and electronic couplings. The results show that during the first 40 fs after a vertical photoexcitation to the S 2 state, the nonadiabatic coupling between S 2 and S 1 states causes a fast transfer of the electronic populations. A rapid decrease of the S 1 -S 2 energy gap is observed, reaching a first conical intersection at ≈5 fs. Therefore, the first hopping events take place, and the S 2 state starts to depopulate. The analysis of the structural and energetic properties of the molecule during the jumps reveals the main role that the ethynylene triple bond plays in the unidirectional energy transfer process.

show abstract

Section: Introductionmentioning

confidence: 99%

Nonadiabatic Molecular Dynamics Simulations of the Energy Transfer between Building Blocks in a Phenylene Ethynylene Dendrimer

et al. 2009

View full text Add to dashboard Cite

show abstract

“…72 Monomer 22 was readily available because methyl gallate could be selectively deprotonated and, therefore, allylated on account of the higher acidity of the 4-hydroxy group. All eight different combinations of inner dendrons 24-27 and outer dendrons 28-31 were prepared and then combined with a double-stage convergent growth approach [73][74][75] to afford a total of 16 fourthgeneration dendron structures (32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47). Methyl benzoates, rather than benzylic alcohols, were used for growth because alkylations proceed with higher degrees of regioselectivity, i.e., no O-alkylation is observed, and the additional reduction step is facilitated by workup with Baeckström's reagent.…”

Section: Aromatic Backbonesmentioning

confidence: 99%

Functionalizing the interior of dendrimers: Synthetic challenges and applications

Hecht

2003

J. Polym. Sci. A Polym. Chem.

119

View full text Add to dashboard Cite

Chemists' fascination with dendrimers mainly originates from their unique architecture and its exploitation for the design of well‐defined functional macromolecules. Depending on the nature of the synthesis, functionalization is traditionally introduced at the core, the periphery, or both. However, the specific incorporation of functional groups at the interior layers, i.e., generations, represents a considerable synthetic hurdle that must be overcome for the full potential of dendrimers to be realized. This review covers recent advances in this emerging frontier of dendrimer science with a particular focus on covalent modifications. Monomer design, syntheses, and properties of various dendritic backbone types are discussed. Internal functionalization dramatically increases the degree of complexity that can be implemented into a dendrimer macromolecule and, therefore, promises to lead to smart materials for future applications in bio‐ and nanotechnologies. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1047–1058, 2003

show abstract

“…Linear unit Self-similar geometry leads to unusual transport and optical properties in these Cayley tree or "Bethe lattice" structures [2][3][4][5][6][7][8][9][10][11]. Application of quantum chemistry methods to calculate the electronic structure of giant molecules is limited by computational power to small systems [12,13].…”

Section: Introductionmentioning

confidence: 99%

Localized Optical Excitations and Two-Exciton Spectroscopy of Phenylacetylene Dendrimers

et al. 1998

View full text Add to dashboard Cite

The one-and two-exciton manifolds of conjugated dendrimers possessing fractal geometries are studied using the Frenkel exciton model. Two-photon spectra can be used to determine both the magnitude and the sign of short-range coupling among segments. Self-similarity and the high degree of symmetry make it possible to compute the one-exciton states and the optical response with reduced numerical effort that scales linearly rather than exponentially with the number of generations. The third-order optical response and exciton scattering matrix are expressed in compact forms using irreducible representation of optical excitations, totally avoiding the expensive explicit calculation of two-exciton eigenstates.

show abstract

Phenylacetylene Dendrimers by the Divergent, Convergent, and Double-Stage Convergent Methods

Cited by 240 publications

References 0 publications

Nonadiabatic Molecular Dynamics Simulations of the Energy Transfer between Building Blocks in a Phenylene Ethynylene Dendrimer

Nonadiabatic Molecular Dynamics Simulations of the Energy Transfer between Building Blocks in a Phenylene Ethynylene Dendrimer

Functionalizing the interior of dendrimers: Synthetic challenges and applications

Localized Optical Excitations and Two-Exciton Spectroscopy of Phenylacetylene Dendrimers

Contact Info

Product

Resources

About