Synthesis, Structure and Spectra Properties of a
Novel BOIMPY Compound①
LI Tuoa, b XU Lanc YIN Zhen-Minga, b②
【摘 要】ABSTRACT A bis-2-iminopyrrole compound (1) and its difluoroboron complex (2) were synthe- sized and characterized. The crystal of 2 is in the monoclinic system, P21/n space group with a = 21.5113(15), b = 6.3036(3), c = 21.5064(15) ?, V = 2826.3(7) ?3, Z = 4, C26.5H25B2ClF4N4O, Mr= 548.57, Dc= 1.390 g/cm, F(000) = 1132 and μ(MoKα) = 1.787 mm-1. The final R = 0.0647 and wR = 0.1817 for 10346 observed reflections with I > 2σ(I), and R = 0.0889 and wR = 0.1993 for all data. The molecules of complex 2 self-assemble through C–H×××F hydrogen bonds and form tubular structures which are filled by CH2Cl2 molecules stabilized by C–H×××π interaction. The UV-Vis spectra of complex 2 show great bathochromic shift compared to that of compound 1 due to the difluoroboron complexing. Complex 2 shows fluorescence emission both in solid state and in solution, whereas compound 1 only exhibits fluorescence emission in solid state. 【期刊名称】结构化学 【年(卷),期】2024(037)006 【总页数】6
【关键词】Keywords: BOIMPY, crystal structure, UV-Vis and fluorescence spectra;
1 INTRODUCTION
In recent years, the research of fluorescent mate- rials has become a new hotspot area in the field of organic chemistry[1]. Because of their unique advan- tages in the characterization of life activities in living organisms[2], fluorescent materials are gradually becoming a necessity for modern chemistry and biology[3]. The fluorescent materials commonly used in the field of chemistry and biology are fluorescein, coumarin and arylmethyl dyes[4, 5].Recently, a novel fluorescent structure, boron-dipyrromethene (BODIPY), has been reported frequently[6, 7]. Planar structure endows BODIPYs with strong fluorescence emission under the action of excitation light. Such compounds also have high molar absorption coeffi- cient, good light stability, excitation wavelength in the visible to near infrared region, easy modification of the structure, not easily affected by the environ- ment, and so on. The success of BODIPY dyes and related compounds led to researches on similar struc- tures such as azo-BODIPY structures[8, 9], boron com- plexes of iminopyrrolide ligands (BOIMPY)[10-13],
bis(difluoroboron)-1,2-bis{(pyrrol-2-
yl)methylene}hydrazine (BOPHY) structures[3, 14-16] and other novel organoboron fluorescence materials[17].
Similar to the BODIPY structure, the BOIMPY structure immobilizes the pyrrole and aromatic rings on the same plane through the boron bridge
bond and the methylene bridge bond. BOIMPY has the advan- tage of lower molecular symmetry which can overcome the shortcoming of short Stokes shifts of BODIPY[18, 19]. However, the study on BOIMPY is still rare[10-13]. Herein, we report the synthesis, crystal structure and spectra properties of a new BOIMPY compound, bis(difluoroboron)-bis{(pyrrol-2-yl)me-thylene-aminophenyl}ether (2, Scheme 1).
2 EXPERIMENTAL
2. 1 Materials and apparatuses
1H NMR spectra were recorded in CDCl3, with TMS as an internal standard, on a BRUKER AV-400 MHz spectrometer. UV-Vis spectra were recorded on the SHIMADZU UV-2550 spectrometer. HR-MS analyses were performed on a Thermo Scientific LTQ Orbitrap XL spectrometer equipped with an ESI source. Fluorescence spectra in solution were recorded on the Gangdong F-280 spectrometer. Solid state fluorescence spectra were recorded on a Horiba Jobin Yvon Fluorolog-3 spectrometer. Melting points (mp) were recorded on an electro-thermal digital melting point apparatus and uncorrected. All reagents were commercially available and used without further purification. 2. 2 Preparation of compound 1
In a 50 mL round-bottomed flask, 3,5-dimethyl- 1H-pyrrole-2-carbaldehyde (2 mmol, 0.24 g), 4,4?-oxydianiline (1 mmol, 0.20 g), and a catalytic amount of AcOH were suspended in 10 mL absolute methanol.
Synthesis, Structure and Spectra Properties of a Novel BOIMPY Compound
