Ring-size dependent orientation in dehydration of 1-[(ethoxycarbonyl)methyl]cycloalkanols

1988 ◽  
Vol 53 (4) ◽  
pp. 893-894 ◽  
Author(s):  
Constantinos G. Screttas ◽  
Ioulia C. Smonou
Keyword(s):  
Ring Size ◽  
Size Dependent

scholarly journals Aromaticity and Antiaromaticity in the Excited States of Porphyrin Nanorings

2019 ◽  
Author(s):  
Martin Peeks ◽  
Juliane Gong ◽  
Kirstie McLoughlin ◽  
Takayuki Kobatake ◽  
Renee Haver ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Density Functional ◽  
Ring Size ◽  
Critical Importance ◽  
Peak Wavelength ◽  
Functional Theory ◽  
Size Dependent ◽  
Nucleus Independent Chemical Shift ◽  
Radiative Rate

Aromaticity can be a useful concept for predicting the behavior of excited states. Here we show that π-conjugated porphyrin nanorings exhibit size-dependent excited-state global aromaticity and antiaromaticity, for rings containing up to eight porphyrin subunits, although they have no significant global aromaticity in their neutral singlet ground states. Applying Baird’s law, odd rings ([4n] π-electrons) are aromatic in their excited states, whereas the excited states of even rings ([4n+2] π-electrons) are antiaromatic. These predictions are borne out by density functional theory (DFT) studies of the nucleus-independent chemical shift in the T1 triplet state of each ring, which reveal the critical importance of the triplet delocalization to the emergence of excited-state aromaticity. The singlet excited states (S1) are explored by measurements of the radiative rate and fluorescence peak wavelength, revealing a subtle odd-even alternation as a function of ring size, consistent with symmetry-breaking in antiaromatic excited states.

Stereogenic cyclic oligonaphthalenes displaying ring size-dependent handedness of circularly polarized luminescence (CPL)

2019 ◽  
Vol 55 (19) ◽  
pp. 2749-2752 ◽  
Author(s):  
Yuki Nojima ◽  
Masashi Hasegawa ◽  
Nobuyuki Hara ◽  
Yoshitane Imai ◽  
Yasuhiro Mazaki
Keyword(s):  
Coupling Reaction ◽  
Ring Size ◽  
Chiroptical Properties ◽  
Circularly Polarized ◽  
Size Dependent ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Cyclic Oligomers

A series of cyclic oligomers with Dn symmetry (n = 2–5) based on chiral (R)/(S)-binaphthyl exhibiting intensive chiroptical properties were synthesized by using a Ni(0)-catalyzed coupling reaction.

scholarly journals Aromaticity and Antiaromaticity in the Excited States of Porphyrin Nanorings

2019 ◽  
Author(s):  
Martin Peeks ◽  
Juliane Gong ◽  
Kirstie McLoughlin ◽  
Takayuki Kobatake ◽  
Renee Haver ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Density Functional ◽  
Ring Size ◽  
Critical Importance ◽  
Peak Wavelength ◽  
Functional Theory ◽  
Size Dependent ◽  
Nucleus Independent Chemical Shift ◽  
Radiative Rate

Aromaticity can be a useful concept for predicting the behavior of excited states. Here we show that π-conjugated porphyrin nanorings exhibit size-dependent excited-state global aromaticity and antiaromaticity, for rings containing up to eight porphyrin subunits, although they have no significant global aromaticity in their neutral singlet ground states. Applying Baird’s law, odd rings ([4n] π-electrons) are aromatic in their excited states, whereas the excited states of even rings ([4n+2] π-electrons) are antiaromatic. These predictions are borne out by density functional theory (DFT) studies of the nucleus-independent chemical shift in the T1 triplet state of each ring, which reveal the critical importance of the triplet delocalization to the emergence of excited-state aromaticity. The singlet excited states (S1) are explored by measurements of the radiative rate and fluorescence peak wavelength, revealing a subtle odd-even alternation as a function of ring size, consistent with symmetry-breaking in antiaromatic excited states.

Photophysics and peripheral ring size dependent aggregate emission of cross-conjugated enediynes: applications to white light emission and vapor sensing

2018 ◽  
Vol 20 (6) ◽  
pp. 4167-4180 ◽  
Author(s):  
Anuja Singh ◽  
Avik Kumar Pati ◽  
Ashok Kumar Mishra
Keyword(s):  
White Light ◽  
Light Emission ◽  
White Light Emission ◽  
Ring Size ◽  
Organic Fluorophores ◽  
Size Dependent ◽  
Vapor Sensing ◽  
Peripheral Ring ◽  
Optoelectronic Applications

Photophysical understanding of organic fluorophores with π-conjugated scaffolds is crucial as such dyes are central to optoelectronic applications.

Charge-Density and Ring-Size Dependent Dimerization of 1-Arylcycloalkene Cation Radicals

2000 ◽  
Vol 73 (7) ◽  
pp. 1557-1565 ◽  
Author(s):  
Masanobu Kojima ◽  
Akito Ishida ◽  
Yasunao Kuriyama ◽  
Shigero Oishi
Keyword(s):  
Charge Density ◽  
Ring Size ◽  
Cation Radicals ◽  
Size Dependent

SYNTHESIS OF p-CHLOROAZACALIX[5]ARENE PENTAMETHYL ETHER: RING SIZE-DEPENDENT DEPROTECTION OF N-BENZYL GROUPS

Heterocycles ◽  
2012 ◽  
Vol 86 (1) ◽  
pp. 159 ◽  
Author(s):  
Hirohito Tsue ◽  
Kazuyuki Miyata ◽  
Daisuke Takahashi ◽  
Hiroki Takahashi ◽  
Kohei Sasaki ◽  
...  
Keyword(s):  
Ring Size ◽  
Size Dependent
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