Aromaticity of substituted fulvene derivatives: substituent-dependent ring currents.
نویسندگان
چکیده
Fulvene is a non-aromatic molecule, but variation of the electron-donating/withdrawing power of substituents exo to the five-membered ring can drive the system between the extremes of aromatic and antiaromatic, as judged by prediction of fully developed diatropic and paratropic ring currents through ab initio calculations made at the ipsocentric 6-31G**/CTOCD-DZ CHF level.
منابع مشابه
Aromatic Character and Energy of the Five- and Seven-Membered Rings in Derivatives of Penta- and Heptafulvene Substituted in Exocyclic Position
Application of aromaticity indices to geometries of rings of eleven derivatives of fulvene, two salts of cyclopentadienyl, and nine derivatives of heptafulvene gives a coherent view in line with expectation due to the (4n + 2) rule: electron-donating substituents attached to exocyclic carbon atom in fulvenes and electron-accepting substituents attached to heptafulvenes increase significantly th...
متن کاملSubstituent effects on the aromaticity of carbocyclic five-membered rings.
The influence of the substituent nature, as well as the number and position of the substituents, on the aromaticity/antiaromaticity of a comprehensive set of derivatives of cyclopentadienyl anion, cyclopentadiene and cyclopentadienyl cation has been analyzed. The aromaticity/antiaromaticity of substituted cyclopentadienyl derivatives has been measured using energetic, magnetic and structural cr...
متن کاملInfluence of excited state aromaticity in the lowest excited singlet states of fulvene derivatives.
The absorption spectra and excited state dipole moments of four differently substituted fulvenes have been investigated both experimentally and computationally. The results reveal that the excited state dipole moment of fulvenes reverses in the first excited singlet state when compared to the ground state. The oppositely polarized electron density distributions, which dominate the ground state ...
متن کاملShannon entropy as a new measure of aromaticity, Shannon aromaticity.
Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...
متن کاملTheoretical investigation on the aromaticity of mono-substituted benzene derivatives by using cyclic reference
The degree of aromaticity of mono-substituted derivatives of benzene has beeninvestigated using a new index based on electric field gradient index, by using two mechanicalquantum methods with Gaussian 03. Two different basis sets have applied to study and theresults compared. This strategy has demonstrated that, due to violation of symmetry in have pisystems,how the degree of aromaticity can ha...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical chemistry chemical physics : PCCP
دوره 12 36 شماره
صفحات -
تاریخ انتشار 2010