title: Fluorescent Molecular Rotors of Organoboron Compounds from Schiff Bases: Synthesis, Viscosity, Reversible Thermochromism, Cytotoxicity, and Bioimaging Cells.
abstract: We report the design, synthesis, and characterization of two new fluorescent molecular rotors of boron derived from Schiff bases: (2,4,8,10-tetra-tert-butyl-6-phenyldibenzo[d,h][1,3,6,2]dioxazaboronine (3) and 1,4-bis(2,4,8,10-tetra-tert-butyldibenzo[d,h][1,3,6,2]dioxazaboronin-6-yl)benzene (4), as well as the free ligand 2-[[(3,5-di-tert-butyl-2-hydroxyphenyl)imino]methyl]-4,6-di-tert-butylphenol 1. All compounds were fully characterized by NMR (1H,11B, and13C), IR, UV/vis, fluorescence spectroscopy, and high-resolution mass spectrometry. The crystal structures of 3 and 4 showed tetracoordinated boron atoms with semiplanar skeleton ligands. The free rotation of the fluorescent molecular rotor, only observed in the binuclear compound, was decreased with increasing viscosity, while the quantum yield was increased. Interestingly, the property of reversible thermochromism was found in organoboron 4 in the solid state. DFT calculations to determine the both complexes have free rotation around the CPh-B1 bond. The boron compounds 3 and 4 have shown low cytotoxicity activity in cell line A-431 and low green staining in cells.
authors.affiliation: Facultad de Ciencias Químicas, Ciudad Universitaria, Universidad Autónoma de Nuevo León , 66451 San Nicolás de los Garza, Nuevo León Mexico.
authors.forename: Marisol
authors.initials: M
authors.lastname: Ibarra-Rodrı Guez
authors.affiliation: Facultad de Ciencias Químicas, Ciudad Universitaria, Universidad Autónoma de Nuevo León , 66451 San Nicolás de los Garza, Nuevo León Mexico.
authors.forename: Blanca M
authors.initials: BM
authors.lastname: Muñoz-Flores
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Arlington , Arlington, Texas 76019-0065, United States.
authors.forename: H V Rasika
authors.identifier: 0000-0002-2362-1331
authors.initials: HV
authors.lastname: Dias
authors.affiliation: Centro de Investigación en Materiales Avanzados , S.C., Alianza Norte 202, PIIT, Carretera Monterrey-Aeropuerto Km 10, CP 66628, Apodaca, Nuevo León Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Sánchez
authors.affiliation: Facultad de Ciencias Químicas, Ciudad Universitaria, Universidad Autónoma de Nuevo León , 66451 San Nicolás de los Garza, Nuevo León Mexico.
authors.forename: Alberto
authors.initials: A
authors.lastname: Gomez-Treviño
authors.affiliation: Departamento de Química, Centro de Investigación y de Estudios Avanzados del IPN , A.P. 14-740, CP 07000 San Pedro Zacatenco, DF, Mexico.
authors.forename: Rosa
authors.initials: R
authors.lastname: Santillan
authors.affiliation: Facultad de Química, Departamento de Química Orgánica, Universidad Nacional Autónoma de México, Ciudad Universitaria , 04510 Mexico City, Mexico.
authors.forename: Norberto
authors.initials: N
authors.lastname: Farfán
authors.affiliation: Facultad de Ciencias Químicas, Ciudad Universitaria, Universidad Autónoma de Nuevo León , 66451 San Nicolás de los Garza, Nuevo León Mexico.
authors.forename: Víctor M
authors.identifier: 0000-0003-4306-2482
authors.initials: VM
authors.lastname: Jiménez-Pérez
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D001896:Boron Compounds; D005456:Fluorescent Dyes; D012545:Schiff Bases