20443-71-4Relevant articles and documents
6MNEP: A molecular cation with large hyperpolarizability and promise for nonlinear optical applications
Bloxham, Joseph C.,Brock, Daniel J.,Jackson, Erika W.,Johnson, Jeremy A.,Kenney, Karissa C.,Michaelis, David J.,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.,Wayment, Adam X.
supporting information, p. 11079 - 11087 (2020/09/09)
Molecular organic crystals are strategically designed for nonlinear optical applications using push-pull chromophores as the core feature. In this approach, electron-donating and accepting groups are connected through a π-conjugated bridge to obtain planar molecules with high hyperpolarizability. However, the non-centrosymmetric packing that is required for nonlinear optical (NLO) applications is a critical challenge that must be addressed to design useful materials. In this article, we present the new organic cation 6MNEP that shows a large hyperpolarizability and can be crystallized in ideal non-centrosymmetric structures for NLO applications, when paired with T and 4NBS anions. The 6MNEP cation was obtained by extending the conjugation length of already existing chromophores. We compare the 6MNEP crystals with other crystals that also have cations with extended conjugation lengths, but result in centrosymmetric crystal structures. Using the effective hyperpolarizability, we found 6MNEP-T and 6MNEP-4NBS to have 1.6 to 2.5 times larger macroscopic nonlinearities than benchmark NLO organic crystals. Additionally, the significantly lower absorption wavelength compared with other state-of-the-art crystals make 6MNEP-T and 6MNEP-4NBS promising materials for NLO applications like intense terahertz generation.
A kinetic study on nucleophilic displacement reactions of aryl benzenesulfonates with potassium ethoxide: Role of K+ ion and reaction mechanism deduced from analyses of LFERs and activation parameters
Um, Ik-Hwan,Kang, Ji-Sun,Shin, Young-Hee,Buncel, Erwin
supporting information, p. 490 - 497 (2013/03/13)
Pseudofirst-order rate constants (kobsd) have been measured spectrophotometrically for the nucleophilic substitution reactions of 2,4-dinitrophenyl X-substituted benzenesulfonates 4a-f and Y-substituted phenyl benzenesulfonates 5a-k with EtOK in anhydrous ethanol. Dissection of k obsd into kEtO- and kEtOK (i.e., the second-order rate constants for the reactions with the dissociated EtO - and ion-paired EtOK, respectively) shows that the ion-paired EtOK is more reactive than the dissociated EtO-, indicating that K + ion catalyzes the reaction. The catalytic effect exerted by K + ion (e.g., the kEtOK/kEtO- ratio) decreases linearly as the substituent X in the benzenesulfonyl moiety changes from an electron-donating group (EDG) to an electron-withdrawing group (EWG), but it is independent of the electronic nature of the substituent Y in the leaving group. The reactions have been concluded to proceed through a concerted mechanism from analyses of the kinetic data through linear free energy relationships (e.g., the Bronsted-type, Hammett, and Yukawa-Tsuno plots). K+ ion catalyzes the reactions by increasing the electrophilicity of the reaction center through a cyclic transition state (TS) rather than by increasing the nucleofugality of the leaving group. Activation parameters (e.g., ΔH? and ΔS?) determined from the reactions performed at five different temperatures further support the proposed mechanism and TS structures.
The SN3-SN2 spectrum. Rate constants and product selectivities for solvolyses of benzenesulfonyl chlorides in aqueous alcohols
Bentley, T. William,Jones, Robert O,Kang, Dae Ho,Koo, Sun
scheme or table, p. 799 - 806 (2010/06/16)
Rate constants for a wide range of binary aqueous mixtures and product selectivities (S) in ethanol - Water (EW) and methanol-water (MW) mixtures, are reported at 25 °C for solvolyses of benzenesulfonyl chloride and the 4-chloro - Derivative. S is defined as follows using molar concentrations: S =([ester product]/[acid product]) × ([water solvent]/[alcohol solvent]). Additional selectivity data are reported for solvolyses of 4-Z-substituted sulfonyl chlorides (Z - OMe, Me, H, Cl and NO2) in 2, 2, 2-trifluoroethanol-water. To explain these results and previously published data on kinetic solvent isotope effects (KSIEs) and on other solvolyses of 4-nitro and 4-methoxybenzenesulfonyl chloride, a mechanistic spectrum involving a change from third order to second order is proposed. The molecularity of these reactions is discussed, along with new term 'SN3-SN2 spectrum' and its connection with the better established term 'S N2-SN1 spectrum'. Copyright
Smiles-type free radical rearrangement of aromatic sulfonates and sulfonamides: Syntheses of arylethanols and arylethylamines
Tada, Masaru,Shijima, Hiroyasu,Nakamura, Masaharu
, p. 2499 - 2505 (2007/10/03)
Smiles-type free radical rearrangements of arenesulfonates and arenesulfonamides are exploited for synthetic purposes. 4-Substituted benzenesulfonates cause Smiles-type rearrangement only when substituted by an electron withdrawing group. Therefore, ipso-sttack by an alkyl radical on arenesulfonates takes place in an electrophilic manner. Arenesulfonamides rearrange only when the amide nitrogen is substituted by an alkoxycarbonyl group, due to the electron withdrawing nature of this group. Sulfonates and the N-ethoxycarbonylsulfonamide derivatives of naphthalene, quinoline, and thiophene cause more rearrangement and show synthetic utility. Aromatic amino acid analogues were synthesized by Smiles-type rearrangement with moderate yields. The radical Smiles-type rearrangement of sulfonate and sulfonamide derivatives can be a useful synthetic route when we understand the electronic character of these reactions.
Reaction of Carboxylic Acid Esters with p-Toluenesulfonic Acid
Nitta, Yoshihiro,Arakawa, Yasushi
, p. 1380 - 1386 (2007/10/02)
The reaction of carboxylic acid esters with an excess of p-toluenesulfonic acid gave the corresponding p-toluenesulfonates.The mechanism of the transesterification is discussed.
