Selective Synthesis and Crystal Structure of [10]Cycloparaphenylene

Kayahara, Eiichi; Sakamoto, Yoichi; Suzuki, Toshiyasu; Yamago, Shigeru

doi:10.1021/ol301242t

Cited by 121 publications

(90 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…32,33 Very recently, we reported the selective synthesis of [10]CPP through an Lshaped cis-substituted bis(para-haloaryl)platinum complex. 34 Theoretical studies by our group have suggested that, 31 in sharp contrast to linear oligoparaphenylenes, the gap between the highest-occupied and lowest-unoccupied molecular orbital (HOMOLUMO gap) of CPPs becomes narrower as the number of phenylene rings decreases, which is due to increasing and decreasing HOMO and LUMO energies, respectively. As a result, compared to larger CPPs, CPPs of small ring size should display a range of intriguing properties, including a higher redox activity.…”

mentioning

confidence: 99%

Selective Synthesis of [6]-, [8]-, and [10]Cycloparaphenylenes

et al. 2013

Self Cite

View full text Add to dashboard Cite

The selective synthesis of [6]-, [8]-, and [10]cycloparaphenylenes (CPPs) was achieved by a new synthetic route involving Ni(0)-mediated coupling of bis(para-haloaryl)dinuclear arylplatinum complexes and the reductive elimination of the complexes. Importantly, the highly strained [6]CPP was prepared in good overall yield.Cycloparaphenylenes (CPPs; Figure 1a), being hoop-shaped ³-conjugated molecules consisting of para-linked phenylene rings, have recently gained much attention from a variety of disciplines, which, besides their structural beauty, is mostly associated with the topologically unique array of ³-orbitals. 15Since CPPs are the smallest structural units of armchair carbon nanotubes (CNTs; Figure 1b), their application in electronic and optoelectronic devices 69 and their use as a seed compound for the synthesis of structurally uniform CNTs have been suggested. 2,5,10 In addition, the cavity of CPPs offers a unique opportunity in supramolecular chemistry to study concave convex ³³ interactions and fabricate hierarchically ordered ³ materials.11,12 Despite their simple structure, however, the synthesis of CPPs was only recently achieved by three groups including our own despite intensive efforts that spanned more than half a century.Bertozzi and Jasti were the first to synthesize [9]-, [12]-, and [18]CPPs utilizing cis-cyclohexa-2,5-diene-1,4-diyl as the key precursor (Scheme 1a). 13 The subsequent extension of this synthetic strategy by Jasti realized the selective synthesis of a series of [6] 12 Isobe applied our method to the synthesis of the shortest sidewall segments of helical CNTs. 32,33 Very recently, we reported the selective synthesis of [10]CPP through an Lshaped cis-substituted bis(para-haloaryl)platinum complex. 34Theoretical studies by our group have suggested that, 31 in sharp contrast to linear oligoparaphenylenes, the gap between the highest-occupied and lowest-unoccupied molecular orbital (HOMOLUMO gap) of CPPs becomes narrower as the number of phenylene rings decreases, which is due to increasing and decreasing HOMO and LUMO energies, respectively. As a result, compared to larger CPPs, CPPs of small ring size should display a range of intriguing properties, including a higher redox activity. Unfortunately, despite recent developments, the synthesis of small CPPs still poses serious synthetic difficulties; the

show abstract

mentioning

confidence: 99%

Selective Synthesis of [6]-, [8]-, and [10]Cycloparaphenylenes

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…After heating at 90°C for 3 h, the 19 F NMR analysis indicated the complete disappearance of the signal at À 271.3 p.p.m. and the appearance of a new singlet peak at À 233.1 p.p.m.…”

Section: Resultsmentioning

confidence: 99%

“…(d) from internal tetramethylsilane or residual solvent peak. 19 F NMR spectra were measured at 376 MHz and are reported in d from external C 6 F 6 (-162.9 p.p.m. ), which was separately calibrated from CCl 3 F (0.0 p.p.m.).…”

Section: Methodsmentioning

confidence: 99%

“…The residue was purified by silica gel chromatography (hexane/CH 2 Cl 2 ¼ 4/1 to 1/1) to give 3 (21.9 mg, 21%) as a pale yellow solid. 1 19 F and 31 P NMR spectrometry after 3, 9 and 18 h. The disappearance of 5e and the formation of several species were observed at 3 and 9 h and the reaction eventually gave Pt(dppf)F 2 ( 19 F NMR; 233.1 p.p.m., 31 P NMR; 9.5 p.p.m., 1 J PtP ¼ 3542.3 Hz) as an exclusive product.…”

Section: Synthesis Ofmentioning

confidence: 97%

“…Our method relies on the formation of a square-shaped tetranuclear aryl platinum complex by the transmetallation of arylmetal species and a platinum dihalide (Fig. 1a) 12,[18][19][20] . The process of the complex formation can be regarded as a covalent bonding version of the self-assembly of structurally related coordination complexes of palladium and platinum macrocycles with, for example 4,4 0 -bipyridyl, in supramolecular chemistry (Fig.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Synthesis and physical properties of a ball-like three-dimensional π-conjugated molecule

et al. 2013

Self Cite

View full text Add to dashboard Cite

Curved p-conjugated molecules with closed and three-dimensional (3D) structures, such as fullerenes and carbon nanotubes, have been the subject of intensive research due to their potential applications in molecular electronics. However, basic molecular skeletons of 3D molecules are limited because of the lack of a rational and selective synthetic method by organic synthesis. Here we report the synthesis of a 3D p-conjugated molecule based on the platinum-mediated assembly of four molecules of a stannylated trisubstituted benzene derivative forming a hexanuclear platinum complex with an octahedral shape, from which reductive elimination of platinum gave the target molecule. As many supramolecular transition metal-ligand complexes with 3D cages and polyhedral structures have been synthesized by self-assembly of ligands and metals, the current assembly/reductive elimination strategy could provide a variety of new 3D p-conjugated molecules with different structures and topologies, which are challenging to obtain using conventional synthetic methods.

show abstract