Optical Excitations in Carbon Architectures Based on Dodecadehydrotribenzo[18]annulene

Anand, Smriti; Varnavski, Oleg; Marsden, Jeremiah A.; Haley, Michael M.; Schlegel, H. Bernhard

doi:10.1021/jp0539573

Cited by 39 publications

(34 citation statements)

References 64 publications

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“…The disappearance of the peak from the terminal phenyl acetylene indicates nearly complete conversion of the monomers in the SAM to the corresponding linked monolayer. A variety of conjugated polymers have been previously synthesized that resemble these linked monolayers (20,21,26,27). The spectroscopic changes observed in the monolayersupported systems are similar to those seen in the literature examples.…”

Section: Resultssupporting

confidence: 62%

“…Similarly, the linked monolayer from 2 on quartz possesses a broad new peak at 370 nm (Fig. 2D) that matches the absorbance of poly(1,4-phenylene-1,3-butadiynylene) derivatives (20,21). This has been described as a delocalized 3 * transition in molecules comprised of multiple 1,4-diphenylbutadiyne chromophores (20).…”

Section: Resultsmentioning

confidence: 57%

“…This has been described as a delocalized 3 * transition in molecules comprised of multiple 1,4-diphenylbutadiyne chromophores (20). The appearance of these lower-energy peaks suggests an increased delocalization of electrons on oligomerization/polymerization resulting from increased conjugation (21). The spectrum of the linked monolayer of 3 is significantly broadened compared with that of the original SAM (Fig.…”

Section: Resultsmentioning

confidence: 89%

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Synthesis of linked carbon monolayers: Films, balloons, tubes, and pleated sheets

Schultz

Zhang

Unarunotai

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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Because of their potential for use in advanced electronic, nanomechanical, and other applications, large two-dimensional, carbon-rich networks have become an important target to the scientific community. Current methods for the synthesis of these materials have many limitations including lack of molecular-level control and poor diversity. Here, we present a method for the synthesis of two-dimensional carbon nanomaterials synthesized by Mo-and Cu-catalyzed cross-linking of alkyne-containing selfassembled monolayers on SiO 2 and Si3N4. When deposited and cross-linked on flat surfaces, spheres, cylinders, or textured substrates, monolayers take the form of these templates and retain their structure on template removal. These nanomaterials can also be transferred from surface to surface and suspended over cavities without tearing. This approach to the synthesis of monolayer carbon networks greatly expands the chemistry, morphology, and size of carbon films accessible for analysis and device applications.networks ͉ nanomaterials ͉ self-assembled I n contrast to carbon nanotubes, fullerenes and various derivatives (1-3), the synthesis of large 2D sheets such as graphene (4), graphyne, and graphdiyne (5, 6) extending over micrometers in lateral dimensions is either in its infancy or has significant limitations. In fact, the synthesis of 2D carbon networks has been recognized as an outstanding challenge in materials chemistry (7).Graphene, the simplest of the 2D conjugated carbon nanomaterials, is produced by micromechanical cleavage of bulk graphite (HOPG) or by thermal decomposition of silicon carbide (8, 9). However, these approaches lack the molecular-level control necessary to define the chemical makeup of these systems. Scholl coupling reactions on oligophenylene precursors (10) produce small (Ͻ15 nm) 2D graphene fragments with improved molecular diversity, and radiation induced modifications of self-assembled (11, 12) or Langmuir-Blodgett (13) monolayers create larger sheets, but with reduced control of the chemistry. Polyelectrolytes (14) represent a different class of chemistry that can form 2D (15) and 3D (16) nanomaterials. These films are formed through deposition of separately synthesized polymers, often in layer-by-layer assemblies, in the form of relatively thick (typically Ͼ5 nm) films governed by electrostatic interactions. These limitations, together with those associated with the planar, radiation-cross-linked monolayers, motivate the need for alternative approaches to these classes of materials.A potential solution to the formation of large 2D conjugated carbon nanomaterials would employ a two-step procedure involving the formation of self-assembled monolayers (SAMs) with highly functionalized monomers followed by chemical crosslinkage of the SAMs to form linked monolayers. Fig. 1 shows the overall process beginning with the formation of SAMs of suitably designed carbon precursors on solid supports, followed by chemical cross-linking to yield covalently bonded networks with monolayer thicknesses. Not...

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Section: Resultssupporting

confidence: 62%

Section: Resultsmentioning

confidence: 57%

Section: Resultsmentioning

confidence: 89%

See 1 more Smart Citation

Synthesis of linked carbon monolayers: Films, balloons, tubes, and pleated sheets

Schultz

Zhang

Unarunotai

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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show abstract

“…The electronic absorption data for "G1" targets 15a and 19-23 exhibit a characteristic pattern of four absorption bands, which are assigned primarily to π→π* transitions in the [18]annulene skeleton [41]. These peaks shift to longer wavelengths and possess greater intensities as the number of longer 1,4-bis(phenylbutadiynyl)benzene chromophores is increased.…”

Section: Properties Of Graphdiyne Substructuresmentioning

confidence: 99%

“…In the area of nonlinear optics, organic multi-chromophore systems such as organic dendrimers have been utilized for two-photon absorption (TPA) effects which may have applications in optical limiting, imaging and photodynamic therapy [42]. Our graphdiyne mimics, which are multi-chromophore structures composed of repeated building block molecules, exhibit intramolecular coupling interactions among the multiple chromophores [41] and thus should lead to enhanced two-photon cross-sections. In addition, the various structures in hand allow us to investigate the influence of symmetry on the characteristics of the ground and excited states that are accessible by oneand two-photon processes, ultimately giving information about the mechanism(s) of the large TPA effect found in related systems.…”

mentioning

confidence: 99%