Journal ArticleDOI
Triplet‐Triplet Spectroscopy of Polyacenes
TLDR
In this article, the LCAO-MO-SCF Pariser-Parr-Pople method was used to estimate the ππ* triplet states energies with the use of large configuration interactions.Abstract:
Complete triplet—triplet absorption spectra (2000–10000 A) were measured in alcoholic solution at 113°K with naphthalene, anthracene, tetracene, and a few methylated derivatives. Several new bands were observed. Calculations of the higher ππ* triplet states energies with the LCAO—MO—SCF Pariser—Parr—Pople method were improved by the use of large configuration interactions. These include many doubly excited configurations with respect to both the ground singlet state S0 and the lowest triplet state T1, thanks to the systematic use of all monoexcitations with respect to S0 plus all monoexcitations with respect to T1. The comparison of all experimental and theoretical results for the three polyacenes allows one to modify a few previous assignments and to give a general tentative assignment for all observed transitions.read more
Citations
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Benchmarks for electronically excited states: CASPT2, CC2, CCSD, and CC3
TL;DR: In this article, a set of 28 medium-sized organic molecules is assembled that cover the most important classes of chromophores including polyenes and other unsaturated aliphatic compounds, aromatic hydrocarbons, heterocycles, carbonyl compounds, and nucleobases.
Journal ArticleDOI
Synthesis and Characterization of Quarteranthene: Elucidating the Characteristics of the Edge State of Graphene Nanoribbons at the Molecular Level
Akihito Konishi,Yasukazu Hirao,Kouzou Matsumoto,Hiroyuki Kurata,Ryohei Kishi,Yasuteru Shigeta,Masayoshi Nakano,Kazuya Tokunaga,Kazuya Tokunaga,Kenji Kamada,Kenji Kamada,Takashi Kubo +11 more
TL;DR: The molecular geometry that was determined from the X-ray analysis is consistent with a zigzag-edge-localized structure of unpaired electrons, and insight into the edge state of ZGNRs can be gained.
Journal ArticleDOI
Tuneable Singlet Exciton Fission and Triplet-Triplet Annihilation in an Orthogonal Pentacene Dimer
Steven Lukman,Andrew J. Musser,Kai Chen,Stavros Athanasopoulos,Chaw K. Yong,Zebing Zeng,Qun Ye,Chunyan Chi,Justin M. Hodgkiss,Jishan Wu,Richard H. Friend,Neil C. Greenham +11 more
TL;DR: In this article, fast and highly efficient intramolecular singlet exciton fission in a pentacene dimer, consisting of two covalently attached, nearly orthogonal units, was reported.
Journal ArticleDOI
A new implementation of the second‐order polarization propagator approximation (SOPPA): The excitation spectra of benzene and naphthalene
TL;DR: In this paper, a new implementation of the second-order polarization propagator approximation (SOPPA) using a direct linear transformation approach is presented, in which the SOPPA equations are solved iteratively.
Journal ArticleDOI
Multiconfigurational Second-Order Perturbation Theory Restricted Active Space (RASPT2) Method for Electronic Excited States: A Benchmark Study
Vicenta Sauri,Luis Serrano-Andrés,Abdul Rehaman Moughal Shahi,Laura Gagliardi,Steven Vancoillie,Kristine Pierloot +5 more
TL;DR: The recently developed second-order perturbation theory restricted active space (RASPT2) method has been benchmarked versus the well-established complete active space approach and extended the applicability of multiconfigurational perturbations theory to much larger and complex systems than previously.
References
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Journal ArticleDOI
Theory of the Electronic Spectra and Structure of the Polyacenes and of Alternant Hydrocarbons
TL;DR: In this paper, a previously given theory of the electronic spectra and structure of complex unsaturated molecules is further elucidated by listing specific formulas for the charge density, bond order, transition moment, and configuration interaction matrix elements.
Journal ArticleDOI
The Electronic Spectra of Aromatic Molecules II: A Theoretical Treatment of Excited States of Alternant Hydrocarbon Molecules based on Self-Consistent Molecular Orbitals
TL;DR: In this article, the theoretical treatment of the electronic spectrum of benzenoid hydrocarbons has been generalized so that full account is taken of electron interaction, based on the use of a self-consistent molecular orbital function for the ground state and corresponding functions for excited states.
Journal ArticleDOI
The Triplet State in Fluid Media
George Porter,Maurice W. Windsor +1 more
TL;DR: In this paper, the triplet-triplet absorption spectra of a variety of organic molecules have been observed in fluid solutions at normal temperatures and the effect of dissolved gases, particularly oxygen, on these lifetimes is described.