1761-62-2Relevant articles and documents
Driving the Emission Towards Blue by Controlling the HOMO-LUMO Energy Gap in BF2-Functionalized 2-(Imidazo[1,5-a]pyridin-3-yl)phenols
Colombo, Gioele,Attilio Ardizzoia,Furrer, Julien,Therrien, Bruno,Brenna, Stefano
, p. 12380 - 12387 (2021)
Several boron compounds with 2-(imidazo[1,5-a]pyridin-3-yl)phenols, differentiated by the nature of the substituent (R) in the para position of the hydroxy group, have been synthesized and thoroughly characterized both in solution (1H, 13C, 11B, 19F NMR) and in the solid state (X-ray). All derivatives displayed attractive photophysical properties like very high Stokes shift, high fluorescence quantum yields and a good photostability in solution. Time-Dependent Density Functional Theory (TD-DFT) calculations allowed to define the main electronic transitions as intra ligand transitions (1ILT), which was corroborated by the Natural Transition Orbitals (NTOs) shapes. The HOMO-LUMO energy gap was correlated to the electronic properties of the substituent R on the phenolic ring, as quantified by its σp Hammett constant.
Schiff bases from TRIS and ortho-hydroxyarenecarbaldehydes: Structures and tautomeric equilibria in the solid state and in solution
Martinez, R. Fernando,Uvalos, Martin,Babiano, Reyes,Cintas, Pedro,Jimenez, Jose L.,Light, Mark E.,Palacios, Juan C.
, p. 3137 - 3145 (2011)
Three Schiff bases generated by conventional condensation of a simple aminopolyol (TRIS) and 5-bromo- and 5-iodosalicylaldehyde, and 2-hydroxy-1-naphthaldehyde, have been fully characterized, both in solution and in the solid state. This study provides a
Two-photon fluorescent probes for biological Mg2+ detection based on 7-substituted coumarin
Yin, Haijing,Zhang, Buchang,Yu, Haizhu,Zhu, Lin,Feng, Yan,Zhu, Manzhou,Guo, Qingxiang,Meng, Xiangming
, p. 4306 - 4312 (2015)
Two novel water-soluble coumarin-based compounds (OC7, NC7) were designed and synthesized as two-photon fluorescent probes for biological Mg2+ detection. The compounds feature a β-keto acid as a high selective binding site for Mg2+ a
Imine or Enamine? Insights and Predictive Guidelines from the Electronic Effect of Substituents in H-Bonded Salicylimines
Cintas, Pedro,Martínez, R. Fernando,Matamoros, Esther,Palacios, Juan C.
, p. 5838 - 5862 (2020/05/20)
Imine and enamine bonds decorate the skeleton of numerous reagents, catalysts, and organic materials. However, it is difficult to isolate at will a single tautomer, as dynamic equilibria occur easily, even in the solid state, and are sensitive to electronic and steric effect, including π-conjugation and H-bonding. Here, using as model Schiff bases generated from salicylaldehydes and TRIS in a set of linear free energy relationships (LFER), we disclose how the formation of either imines or enamines can be controlled and provide a comprehensive framework that captures the structural underpinning of this prediction. This work highlights the potentiality of tailor-made designs en route to compounds with desirable functionality.
Ultrasonically assisted halogenation of aromatic compounds using isoquinolinium bound hypervalent chromium and tetrabutylammonium halides in PEG-600 solutions under acid free and solvent-free conditions
Sambashiva Rao,Ramesh, Kola,Rajanna,Chakrvarthi
, p. 1892 - 1896 (2018/07/10)
Isoquinolinium bound Cr(VI) reagents like isoquinolinium dichromate (IQDC) and isoquinolinium chlorochromate (IQCC) have been successfully accomplished as efficient reagents for oxidative halogenation of aromatic compounds using tetrabutylammonium halide (TBAX) as halogenating agents in aqueous polyethylene glycol (PEG-600) under acid free conditions. Tetrabutylammonium bromide (TBAB) has been used for bromination and tetrabutylammonium iodide (TBAI) for iodination. The halogenation reactions that occurred smoothly in 2 to 7 h under conventional conditions are accelerated magnificently under sonication with few minutes (25 to 70 min) of reaction time and fairly good yields. The reactions occurred at moderate temperature under mild and environmentally safe conditions with simple work up.
