2025-95-8Relevant articles and documents
Energy transfer in bichromophoric molecules: The effect of symmetry and donor/acceptor energy gap
Yip,Levy, Donald H.,Kobetic, Renata,Piotrowiak, Piotr
, p. 10 - 20 (1999)
The dependence of the rate of singlet excitation transfer on the donor-acceptor energy gap was investigated in bichromophoric spiranes with symmetry-forbidden zero-order electronic coupling. The fluorescence measurements were performed in a supersonic jet in order to avoid collisional and inhomogeneous line broadening. Fluorescence excitation spectra and single-vibronic-level emission spectra of the model chromophores cyclopentaphenanthrene and 1,8-dimethylnaphthalene and the bichromophores spirofluorenephenanthrene and spirofluorenenaphthalene are presented and analyzed. Although the transition moments of the linked chromophores are rigorously perpendicular and the exchange coupling between the v′ = 0 states is computationally shown to be zero, all spiranes with energy gaps larger than ～1000 cm-1 exhibited complete electronic energy transfer from all vibrational states of the electronically excited donor, including the undistorted v′ = 0 state. This behavior is explained in terms of vibronic coupling between the sparse states of the donor and the dense manifold (pseudocontinuum) of the acceptor states. The electronic energy transfer was sufficiently fast to result in measurable lifetime broadening of the donor absorption lines, from which the kEET was estimated. The results demonstrate that the zero-order picture overestimates the degree of the molecular orbital symmetry control over electronic energy transfer and charge-transfer rates and that at sufficiently high driving forces the vibronically mediated "symmetry-forbidden" electronic energy transfer can be very rapid (～1 × 1012 s-1).
Synthesis of anti-4,5,14,15-Tetramethyl2>(2,7)naphthalenophane-1,11-diene and its Dianion. ESR and ENDOR Studies of its Radical Anion and Other Related Radical Ions
Rohrbach, William D.,Gerson, Fabian,Moeckel, Reinhart,Boekelheide, Virgil
, p. 4128 - 4132 (1984)
A synthesis of anti-4,5,14,15-tetramethyl2>(2,7)naphthalenophane-1,11-diene (4) has been achived in ten steps from 1,8-naphthalic anhydride in an overall yield of 4percent.The key step in the synthesis employed a double-barreled sulfur analogue of the Sommelet-Hauser rearrangement.Unexpectedly, formation of the dianion and radical anion of 4 occured without intramolecular cyclization.The radical anions and the radical cations both of 4 and of anti-4,5,14,15-tetramethyl2>(2,7)naphthalenophane (19) have been characterized by ESR and ENDOR spectroscopy.
EVIDENCE FOR THE EXISTENCE OF PEROXONIUM INTERMEDIATES
Mitchell, John C.,Heaton, Simon,Porter, Ned A.
, p. 3769 - 3772 (1984)
Low temperature 1H and 2H nmr are consistent with the presence of peroxonium intermediates in the intramolecular alkylation of two different bromoperoxides.In one case decomposition of this peroxonium intermediate results in unusual heterolytic oxygen-oxygen bond cleavage and methyl migration.
Unique behavior of 2,6-bis(bromomethyl)naphthalene as a highly active organic DNA crosslinking molecule
Higashi, Toshinori,Uemura, Koichi,Inami, Keiko,Mochizuki, Masataka
, p. 3568 - 3571 (2009)
Among 14 bis-halomethylated naphthalenes and quinolines, 2,6-bis(bromomethyl)naphthalene was found to have highly active crosslinking activity on DNA. The unique behavior of high microbial mutagenicity, even though it had a low propensity to form double-strands in linearized plasmid DNA, suggested that it would offer a new seed, capable of forming intrastrand crosslinks similar to cisplatin. The electron withdrawal extent of the halogen atoms, the substitution patterns of two halomethyl groups, and the introduction of a nitrogen atom into the aromatic nucleus had remarkable effects on the activity of the molecule.
Eight-membered-ring diaminocarbenes bearing naphthalene moiety in the backbone: DFT studies, synthesis of amidinium salts, generation of free carbene, metal complexes, and solvent-free copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction
Chesnokov, Gleb A.,Topchiy, Maxim A.,Dzhevakov, Pavel B.,Gribanov, Pavel S.,Tukov, Aleksandr A.,Khrustalev, Victor N.,Asachenko, Andrey F.,Nechaev, Mikhail S.
supporting information, p. 4331 - 4345 (2017/04/03)
A new type of eight-membered ring N-heterocyclic carbene (NHC) bearing a rigid naphthalene moiety in the backbone is reported for the first time. Stereoelectronic properties of 4,5-dihydro-1H-naphtho[1,8-ef][1,3]diazocin-3(2H)-ylidene (NaphtDHD) and small
1-Aminobenzocyclobutene-1-phosphonic Acid and Related Compounds as Inhibitors of Phenylalanine Ammonia-Lyase
Zoń, Jerzy,Miziak, Piotr
, (2017/05/17)
Five new geminal aminocycloalkanephosphonic acids (4 – 8) containing both an aromatic ring and a cycloalkane ring were synthesized and evaluated as potential inhibitors of buckwheat phenylalanine ammonia-lyase (PAL). Within the set of compounds which are related to 2-aminoindane-2-phosphonic acid (AIP, 3), a known powerful inhibitor of PAL, racemic 1-aminobenzocyclobutene-1-phosphonic acid (4), was six times weaker than AIP as an in vitro inhibitor of buckwheat PAL, but six times stronger than AIP as an in vivo inhibitor of phenylalanine-derived anthocyanin synthesis in buckwheat.
Synthesis and properties of dicarboximide derivatives of perylene and azaperylene
Nagao, Yukinori,Yoshida, Tatsurou,Arimitsu, Koji,Kozawa, Kozo
experimental part, p. 1197 - 1213 (2010/10/04)
The N-alkyl dicarboximide derivatives of naphthylisoquinoline and binaphthalene were prepared by the hetero coupling reaction of the corresponding N-alkyl dicarboximide derivatives of stannylnaphthalene with bromodimethyisoquinoline and bromodimethylnaphthalene, respectively. The ring closing of the N-hexyl derivatives of naphthylisoquinoline and binaphthalene produced the N-hexyldicarboximide derivatives of azaperylene and perylene having the same substituents, respectively. The absorption spectra and fluorescence spectra of the azaperylene and perylene derivatives were investigated.
Secondary interactions in crystals of all ten isomers of Di(bromomethyl)naphthalene
Jones, Peter G.,Kus, Piotr
experimental part, p. 433 - 444 (2010/10/01)
The packing of all ten isomers of di(bromomethyl)naphthalene is analysed; nine of the structures were determined here, one (the 1,8-isomer) was already known. The 1,5- and 2,6-isomers display crystallographic inversion symmetry and the 2,7-isomer mirror symmetry through the central bond. For the 1,2-, 1,7- and 2,7-isomers, the bromomethyl groups point to the same side of the ring system, and for all other isomers to opposite sides. As expected, the molecules are linked into aggregates by various types of interactions: weak hydrogen bonds CH...Br, Br...Br interactions, CH...π contacts, π ...π stacking and Br...π contacts. The weak hydrogen bonds tend to be numerous but relativelyi; long, and do not combine to form readily recognisable patterns; a more readily assimilated view of the packing is based on the Br...Br interactions, which are observed for all isomers except 1,7 and 2,3, and in some cases lead to aggregation to form quadrilaterals or chains. With decreasing frequency, the interactions π ...π, C-H...π and Br...π are observed, but the latter are rare (just two examples) and very asymmetric, with contacts to only one or two carbons.
A novel fluoride ion colorimetric chemosensor
Hyoung, Min Yeo,Byung, Ju Ryu,Kye, Chun Nam
supporting information; scheme or table, p. 2931 - 2934 (2009/04/18)
(Figure Presented) A novel phosphonium derivative of naphthalene was synthesized by the reaction of 1,8-dibromomethylnaphthalene with triphenylphosphine, which only showed a distinct color change when treated with fluoride ions.
Mononuclear and polynuclear chain complexes of a series of multinucleating N/S donor ligands
Ronson, Tanya K.,Adams, Harry,Ward, Michael D.
, p. 4533 - 4549 (2007/10/03)
We have prepared a series of five ligands with potentially N,S-bidentate chelating arms derived from 3-[2-(methylsulfanyl)phenyl]pyrazole linked to central aromatic spacers by methylene units. Complexes with a variety of architectures have been obtained, including simple mononuclear complexes and polynuclear chain complexes. The p-xylyl-spaced ligand L1 forms one-dimensional helical coordination polymers with copper(I) and silver(I) ions. These polymers display interligand aromatic stacking interactions within each helical chain. The m-xylyl-spaced ligand L2 forms a coordination polymer with copper(I) but a mononuclear complex with the larger silver(I) ion in which the central phenyl ring is involved in an η1 π-type Ag...C interaction with the AgI. The 3,3′-biphenyl-spaced ligand L3 also forms one-dimensional polymers with silver(I) and copper(I) ions, but in this case the sequence of bridging ligands between one metal centre and the next follows a zig-zag path rather than being helical. The 1,8-naphthyl-spaced ligand L4 only forms mononuclear complexes with copper(I) and silver(I) ions showing that this spacer is not large enough to enforce a bridging coordination mode. The three-armed ligand L5, prepared from 2,4,6-tris-(bromomethyl)mesitylene, also forms a mononuclear complex with silver(I) ions, where one of the three arms is pendant. However, when excess silver(I) ions are present two of these mononuclear complexes can be assembled into the trinuclear complex [Ag3(L5) 2] (ClO4)3. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
