Resonance Raman spectra of polyyne molecules C10H2 and C12H2 in solution

Wakabayashi, Tomonari; Tochihara, Hiroshi; Doi, Tatsuya; Nagayama, Hiroyuki; Okuda, Koji; Umeda, Rui; Hisaki, Ichiro; Sonoda, Motohiro; Tobe, Yoshito; Minematsu, Toshie; Hashimoto, Kenro; Hayashi, Shinji

doi:10.1016/j.cplett.2006.11.077

Cited by 50 publications

(59 citation statements)

References 14 publications

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“…The UV absorption spectrum of hexayne H in dichloromethane (Figure 2 a) shows an intense band at 275–325 nm, with a well-defined progression of ∼2060 cm –1 , corresponding to the C≡C vibrational mode of the S n state. 9 , 27 − 36 , 56 The vibrational progression matches well with the ground-state C≡C stretch frequency (2165–2191 cm –1 ) seen in the IR spectrum (Figure 2 b). Hexayne H also displays a weak absorption band at 350–450 nm, dominated by a vibrational progression of 2040–2169 cm –1 (inset in Figure 2 a).…”

Section: Results and Discussionsupporting

confidence: 72%

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

et al. 2014

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We have used single-crystal X-ray diffraction and time-resolved UV–NIR–IR absorption spectroscopy to gain insights into the structures and excited-state dynamics of a rotaxane consisting of a hexayne chain threaded through a phenanthroline macrocycle and a family of related compounds, including the rhenium(I) chlorocarbonyl complex of this rotaxane. The hexayne unit in the rhenium-rotaxane is severely nonlinear; it is bent into an arc with an angle of 155.6(1)° between the terminal C1 and C12 atoms and the centroid of the central C–C bond, with the most acute distortion at the point where the polyyne chain pushes against the Re(CO)3Cl unit. There are strong through-space excited-state interactions between the components of the rotaxanes. In the metal-free rotaxane, there is rapid singlet excitation energy transfer (EET) from the macrocycle to the hexayne (τ = 3.0 ps), whereas in the rhenium-rotaxane there is triplet EET, from the macrocycle complex 3MLCT state to the hexayne (τ = 1.5 ns). This study revealed detailed information on the short-lived higher excited state of the hexayne (lifetime ∼1 ps) and on structural reorganization and cooling of hot polyyne chains, following internal conversion (over ∼5 ps). Comparison of the observed IR bands of the excited states of the hexayne with results from time-dependent density functional calculations (TD DFT) shows that these excited states have high cumulenic character (low bond length alternation) around the central region of the chain. These findings shed light on the complex interactions between the components of this supramolecular rotaxane and are important for the development of materials for the emerging molecular and nanoscale electronics.

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Section: Results and Discussionsupporting

confidence: 72%

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

et al. 2014

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“…The chemical shifts computed with the CAM-B3LYP functional compare well with earlier experimental and computed values reported for PY chains [35][36][37][38] . For PY with n=16, the chemical shift we predict ranges between 56-65 ppm, which compares very well to the experimental value reported by Tykwinski (57-69 ppm) 38 .…”

Section: Methodssupporting

confidence: 73%

“…Various experimental and theoretical reports are available in the literature studying the NMR of short chain polymers, especially, the polyyne backbone with terminal substituents [35][36][37][38] . Recently, Tykwinski et al They, along with other authors, found oscillations in chemical shift between the adjacent carbon atoms.…”

Section: 4 Chemical Shift ()mentioning

confidence: 99%

Impact of Donor–Acceptor Functionalization on the Properties of Linearly π-Conjugated Oligomers: Establishing Quantitative Relationships for the Substituent and Substituent Cooperative Effect Based on Quantum Chemical Calculations

et al. 2013

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To understand better the impact of donor-acceptor substitution on the properties of linearly -conjugated compounds, we performed a computational study on a series of variably substituted transpolyacetylenes, polyynes, and polythiophenes. The focus of this work is on how rapidly the impact of a given substituent or a given combination of substituents vanishes along the -conjugated chain. The response of the structural (bond-length alternation, rotational barrier) and molecular properties ((hyper)polarizability, chemical shift) to substitution is analyzed using different protocols, including a superposition model for the evaluation of the cooperative effect of substituents in homo-and heterosubstituted oligomers. With the exception of the (hyper)polarizability, the impact of donor-acceptor substitution is found to vanish following an exponential. The rate of decay of the substituent impact is found to be characteristic for each backbone, whereas the choice of substituent determines the absolute value of the respective property. The combination of substituents is shown to determine whether the substituent cooperative effect on a property is of an enhancing or damping nature. The rate of decay of the cooperative effect on most properties, including the (hyper)polarizability, is also found to follow an exponential law. With the exception of the (hyper-)polarizability, the impact of donor-acceptor substitution is found to vanish following an exponential. The rate of decay of the substituent impact is found to be characteristic for each backbone, whereas the choice of substituent determines the absolute value of the respective property. The combination of substituents is shown to lead whether the substituent cooperative effect on a property is of enhancing or damping nature. The rate of decay of the cooperative effect on most properties, including the (hyper-)polarizability, is also found to follow an exponential law.

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“…32 The applicability of Raman to different types of samples from powder, to film and moieties, and even in liquids makes this technique extremely valuable to access a number of different sp-carbon systems. [33][34][35][36] On the other hand, Raman has limited sensitivity when the amount of material is scarce and, except for special cases like graphene, enhancement techniques like Surface Enhanced Raman Scattering (SERS) are often required to record a spectrum. 37 Thus, the use of Raman on atomically thin layers of sp-carbon wires produced in vacuum appears to be particularly challenging for the scarcity of probed material and for the stability issues of the system when exposed to the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Scanning tunneling microscopy and Raman spectroscopy of polymeric sp–sp² carbon atomic wires synthesized on the Au(111) surface

et al. 2019

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Resonance Raman spectra of polyyne molecules C10H2 and C12H2 in solution

Cited by 50 publications

References 14 publications

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

Impact of Donor–Acceptor Functionalization on the Properties of Linearly π-Conjugated Oligomers: Establishing Quantitative Relationships for the Substituent and Substituent Cooperative Effect Based on Quantum Chemical Calculations

Scanning tunneling microscopy and Raman spectroscopy of polymeric sp–sp² carbon atomic wires synthesized on the Au(111) surface

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Resonance Raman spectra of polyyne molecules C10H2 and C12H2 in solution

Cited by 50 publications

References 14 publications

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

Impact of Donor–Acceptor Functionalization on the Properties of Linearly π-Conjugated Oligomers: Establishing Quantitative Relationships for the Substituent and Substituent Cooperative Effect Based on Quantum Chemical Calculations

Scanning tunneling microscopy and Raman spectroscopy of polymeric sp–sp2 carbon atomic wires synthesized on the Au(111) surface

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Scanning tunneling microscopy and Raman spectroscopy of polymeric sp–sp² carbon atomic wires synthesized on the Au(111) surface