Quinoline cyanine short-wave infrared dye transparent to visible light as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of dyes and provides a quinoline cyanine short-wave infrared dye as well as a preparation method and application thereof. In the quinoline cyanine short-wave infrared dye disclosed by the invention, the No.7 site of a quinoline unit is an electron withdrawing group; the preparation method comprises the following steps: reacting a 4-methylquinoline compound, iodoethane and acetonitrile in a protective atmosphere to obtain a 4-methylquinoline salt intermediate; the 4-methylquinoline salt intermediate, 2-chloro-3-((phenyl amino) methylene cyclohexene-1-yl) methylene aniline salt, piperidine and ethyl alcohol are subjected to a reaction under the protective atmosphere, and the quinoline cyanine short-wave infrared dye is obtained. The quinoline cyanine dye QC7 is obtained through a condensation reaction of a quinoline salt intermediate and a corresponding Schiff base intermediate, and the quinoline cyanine dye QC7 has an extremely low molar extinction coefficient in a visible light wavelength range and forms a transparent window in a visible light region; and a high molar extinction coefficient is achieved in near-infrared and short-wave infrared regions.

Description

Technical Field

[0001] This invention relates to the field of dye technology, and in particular to a visible-light transparent quinoline cyanine short-wave infrared dye, its preparation method, and its application. Background Technology

[0002] With the rapid development of sustainable energy development, intelligent security, and modern medical technologies, the demand for high-performance photosensitive functional dyes is increasing. In recent years, organic dyes capable of selectively absorbing specific wavelengths, particularly those exhibiting low absorption in the visible light region (VIS, 400–700 nm) and strong absorption in the near-infrared (NIR, 700–1000 nm) and short-wave infrared (SWIR, 1000–2000 nm) regions, have become a research hotspot in related fields. For example, in the field of building-integrated photovoltaics (BIPV), to balance building lighting and aesthetics, dyes need to have high transparency in the visible light region while efficiently absorbing solar energy and converting it into electricity in the near-infrared and short-wave infrared regions. In the fields of night vision and intelligent security, due to the strong penetration and low background noise of the short-wave infrared band in environments such as smoke, rain, and fog, high-performance short-wave infrared dyes can be used for status monitoring in complex environments such as special marking, stealth anti-counterfeiting, and nighttime target identification, thereby enhancing the perception capabilities of intelligent security and automation systems. Furthermore, with the development of fluorescence imaging technology, short-wave infrared dyes can significantly improve tissue penetration depth and imaging resolution in precision medical scenarios such as surgical navigation, effectively reducing tissue damage and postoperative complications.

[0003] Therefore, developing photosensitive functional dyes that possess high transparency in the visible light region and strong absorption properties in the near-infrared and short-wave infrared regions has significant application value and broad market prospects in multiple cutting-edge technology fields. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a visible-light transparent quinoline cyanine short-wave infrared dye, its preparation method, and its application.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] This invention provides a visible-light transparent quinoline cyanine short-wave infrared dye, wherein the quinoline unit has an electron-withdrawing group at position 7.

[0007] Preferably, the visible-light-transparent quinoline cyanine short-wave infrared dye has the following structural formula:

[0008]

[0009] Among them, R1 is independent:

[0010]

[0011] n is any integer from 1 to 20;

[0012] R2 is independent of:

[0013] The present invention also provides a method for preparing the visible-light-transparent quinoline cyanine short-wave infrared dye, comprising the following steps:

[0014] 1) 4-methylquinoline compound, iodoethane and acetonitrile were reacted under a protective atmosphere to obtain 4-methylquinoline salt intermediate;

[0015] 2) Mix 4-methylquinoline salt intermediate, 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, piperidine and ethanol, and react the mixture under a protective atmosphere to obtain a visible-transparent quinoline cyanine short-wave infrared dye.

[0016] Preferably, the 4-methylquinoline compound in step 1) comprises 7-fluoro-4-methylquinoline, 7-chloro-4-methylquinoline, 7-bromo-4-methylquinoline, 7-iodo-4-methylquinoline, 7-trifluoromethyl-4-methylquinoline, 7-cyano-4-methylquinoline, 7-sulfono-4-methylquinoline, or 7-nitro-4-methylquinoline;

[0017] The structural formula of the 4-methylquinoline salt intermediate is:

[0018]

[0019] Among them, R1 is independent:

[0020]

[0021] n is any integer from 1 to 20.

[0022] Preferably, the reaction temperature in step 1) is 80–90°C and the reaction time is 22–26 h.

[0023] Preferably, the molar ratio of the 4-methylquinoline compound and iodoethane in step 1) is 1:12-25; and the molar volume ratio of the 4-methylquinoline compound and acetonitrile is 1 mmol:2-20 mL.

[0024] Preferably, the reaction temperature in step 2) is 85–95°C and the reaction time is 22–26 h.

[0025] Preferably, in step 2), the molar ratio of the 4-methylquinoline salt intermediate to the 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt is 0.12–0.2:0.06–0.09; the volume ratio of piperidine to ethanol is 0.08–0.12:1.5–2.5; and the molar volume ratio of the 4-methylquinoline salt intermediate to piperidine is 0.12–0.2 mmol:0.08–0.12 mL.

[0026] This invention also provides the application of the visible-light-transparent quinoline cyanine short-wave infrared dye in building-integrated photovoltaics, night vision imaging, and deep tissue fluorescence imaging.

[0027] The beneficial effects of this invention include the following:

[0028] 1) This invention obtains a visible-light transparent quinoline cyanine short-wave infrared dye QC7 through a condensation reaction between a quinoline salt intermediate and a corresponding Schiff base intermediate. The quinoline cyanine dye QC7 has an extremely low molar extinction coefficient in the visible light wavelength range (400-700nm), forming a "transparent window" in the visible light region; while it has a high molar extinction coefficient in the near-infrared and short-wave infrared regions (700-1200nm).

[0029] 2) The quinoline cyanine short-wave infrared dye QC7 of this invention exhibits high transparency in the visible light region and strong absorption properties in the near-infrared and short-wave infrared regions. This invention utilizes molecular rational design to precisely construct the quinoline cyanine dye system. By introducing different electron-withdrawing groups into the quinoline salt matrix for structural modification, the spectral distribution and luminescence brightness of the dye are optimized. The quinoline cyanine dye QC7 of this invention has a maximum absorption wavelength range of 960–1046 nm, a maximum emission wavelength range of 983–1075 nm, and a luminescence brightness of 4000–380 nm. -1 cm -1 The molar extinction coefficients are all greater than 2 × 10⁻⁶. 5 M -1 cm -1 The dyes of this invention have a much lower absorption efficiency in the visible light region than in the near-infrared and short-wave infrared regions, and have broad application prospects in fields such as building-integrated photovoltaics, night vision and intelligent security, and deep tissue fluorescence imaging. Attached Figure Description

[0030] Figure 1 The UV absorption and fluorescence emission spectra of dye QC7-CN in dichloromethane are shown in Example 1.

[0031] Figure 2 The UV absorption and fluorescence emission spectra of dye QC7-F in dichloromethane are shown in Example 2.

[0032] Figure 3 The UV absorption and fluorescence emission spectra of dye QC7-CF3 in dichloromethane are shown in Example 3.

[0033] Figure 4 Short-wave infrared fluorescence imaging of dye QC7-CN in Example 1 on BALB / c nude mice. Detailed Implementation

[0034] This invention provides a visible-light transparent quinoline cyanine short-wave infrared dye, wherein the quinoline unit has an electron-withdrawing group at position 7.

[0035] In this invention, the preferred structural formula of the visible-light-transparent quinoline cyanine short-wave infrared dye is:

[0036]

[0037]

[0038] Among them, the preferred option for independent R1 is:

[0039]

[0040] n is preferably any integer from 1 to 20, more preferably any integer from 1 to 10, and even more preferably any integer from 1 to 5;

[0041] The preferred option for independent R2 is:

[0042] In the quinoline cyanine short-wave infrared dye of the present invention, R1 is preferably... n is preferably any integer from 1 to 10, more preferably any integer from 1 to 6, and R2 is preferably...

[0043] The present invention also provides a method for preparing the visible-light-transparent quinoline cyanine short-wave infrared dye, comprising the following steps:

[0044] 1) 4-methylquinoline compound, iodoethane and acetonitrile were reacted under a protective atmosphere to obtain 4-methylquinoline salt intermediate;

[0045] 2) Mix 4-methylquinoline salt intermediate, 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, piperidine and ethanol, and react the mixture under a protective atmosphere to obtain a visible-transparent quinoline cyanine short-wave infrared dye.

[0046] In this invention, the 4-methylquinoline compound in step 1) preferably comprises 7-fluoro-4-methylquinoline, 7-chloro-4-methylquinoline, 7-bromo-4-methylquinoline, 7-iodo-4-methylquinoline, 7-trifluoromethyl-4-methylquinoline, 7-cyano-4-methylquinoline, 7-sulfono-4-methylquinoline, or 7-nitro-4-methylquinoline;

[0047] The preferred structural formula of the 4-methylquinoline salt intermediate is:

[0048]

[0049] Among them, the preferred option for independent R1 is:

[0050]

[0051] n is preferably any integer from 1 to 20, more preferably any integer from 1 to 10, and even more preferably any integer from 1 to 5.

[0052] In this invention, the reaction temperature in step 1) is preferably 80-90°C, more preferably 82-88°C, and even more preferably 85-86°C. The reaction time is preferably 22-26 hours, more preferably 23-25 ​​hours, and even more preferably 24 hours.

[0053] In this invention, the molar ratio of the 4-methylquinoline compound and iodoethane in step 1) is preferably 1:12-25, more preferably 1:15-20, and even more preferably 1:17-18; the molar volume ratio of the 4-methylquinoline compound and acetonitrile is preferably 1 mmol:2-20 mL, more preferably 1 mmol:2.5-18 mL, and even more preferably 1 mmol:3-15 mL.

[0054] In this invention, the reaction temperature in step 2) is preferably 85-95°C, more preferably 87-93°C, and even more preferably 90°C, and the reaction time is preferably 22-26h, more preferably 23-25h, and even more preferably 24h.

[0055] In this invention, the molar ratio of the 4-methylquinoline salt intermediate and the 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt in step 2) is preferably 0.12–0.2:0.06–0.09, more preferably 0.13–0.18:0.07–0.085, and even more preferably 0.15–0.16:0.075–0.08; the volume ratio of piperidine to ethanol is preferably 0.08–0.12:1.5–2.5, more preferably 0.09–0.11:1.7–2.3, and even more preferably 0.1:2; the molar volume ratio of the 4-methylquinoline salt intermediate to piperidine is preferably 0.12–0.2 mmol:0.08–0.12 mL, more preferably 0.13–0.18 mmol:0.09–0.11 mL, and even more preferably 0.15–0.16 mmol:0.1 mL.

[0056] The protective atmosphere described in steps 1) and 2) of this invention is preferably a nitrogen atmosphere or an argon atmosphere.

[0057] This invention also provides the application of the visible-light-transparent quinoline cyanine short-wave infrared dye in building-integrated photovoltaics, night vision imaging, and deep tissue fluorescence imaging.

[0058] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0059] Example 1: Synthesis of dye QC7-CN

[0060]

[0061] 4.5 mmol of 7-bromo-4-methylquinoline, 5.0 mmol of K₄[Fe(CN)₆], 0.09 mmol of Pd(OAc)₂, and 10 mL of toluene were added to a 50 mL Shrek tube and reacted at 95 °C for 24 h under argon protection. After the reaction was completed, the mixture was cooled, and toluene was removed by rotary evaporation. The crude product was purified by silica gel column chromatography (petroleum ether and dichloromethane in a volume ratio of 3:1). After rotary evaporation, a white solid product, 7-cyano-4-methylquinoline, was obtained, with a yield of 95%.

[0062] 1H-NMR (400MHz, CDCl3, ppm): δ2.75 (s, 3H, CH3-Ph), 7.39 (d, J=4.4Hz, 1H, Ph-H), 7.73 (dd, J1=8.6Hz, J2= 1.6Hz, 1H, Ph-H), 8.11 (d, J = 8.8Hz, 1H, Ph-H), 8.48 (d, J = 1.2Hz, 1H, Ph-H), 8.90 (d, J = 4.0Hz, 1H, Ph-H). 13 C-NMR (100MHz, CDCl3, ppm): δ18.66,112.59,118.53,124.18,125.53,126.99,130.46,135.89,144.59,146.91,152.01.Massspectrometry (ESI-MS, m / z): [M+H] + calcd.for[C 11 H8N2+H] + 169.0766; found: 169.0769.

[0063]

[0064] 0.86 mmol of 7-cyano-4-methylquinoline, 17.24 mmol of iodoethane, and 2 mL of acetonitrile were added to a 50 mL Shrek tube, and the reaction was carried out at 85 °C for 24 h under argon protection. After the reaction was completed, the acetonitrile solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane and methanol in a volume ratio of 90:10). After rotary evaporation, a bright yellow product, 7-cyano-4-methylquinoline salt (231 mg, 0.71 mmol), was obtained, with a yield of 53%.

[0065] 1 H-NMR (400MHz, CD3OD, ppm): δ1.75(t,J=7.2Hz,3H,-CH3),3.11(s,3H,CH3-Ph),5.14(q,J=7.2Hz,2H,-CH2-N + ),8.15(d,J=6.0Hz,1H,Ph-H),8.29(dd,J1=8.8Hz,J2=1.2Hz,1H,Ph-H),8.75(d,J=8.8Hz,1H,Ph-H),9.17(s,1H,Ph-H),9.45(d,J=6.0Hz,1H,Ph-H). 13C-NMR (100MHz, CD3OD, ppm): δ15.77,20.50,54.98,118.01,119.39,126.01,126.33,130.14,131.93,132.75,138.10,151.08,161.14.Mass spectrometry(ESI-MS,m / z):[M] + calcd.for[C 13 H 13 N2] + 197.1079; found: 197.1071.

[0066]

[0067] 0.15 mmol of 7-cyano-4-methylquinoline salt, 0.08 mmol of 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, 0.1 mL of piperidine, and 2 mL of anhydrous ethanol were added to a 50 mL Shrek tube. The tube was frozen with liquid nitrogen, deoxygenated three times under vacuum (100 Pa), and reacted at 90 °C for 24 h under argon protection. A precipitate formed after the reaction. The precipitate was filtered and washed with ultrapure water to remove salt, yielding a dark brown solid product: dye QC7-CN (37 mg, 0.056 mmol), with a yield of 73%.

[0068] 1 H-NMR (400MHz, DMSO-d6, ppm): δ1.39(t,J=6.8Hz,6H,-CH3),1.85(t,2H,-CH2-),2.81(t,4H, -CH2-),4.47(q,J=7.2Hz,4H,-CH2-N),7.07(d,J=13.6Hz,2H,Alkene-H),7.45(d,J=7.6Hz,2 H,Ph-H),7.90(d,J=9.6Hz,2H,Ph-H),7.98(d,J=13.6Hz,2H,Alkene-H),8.16(d,J=7.2Hz,2H ,Ph-H),8.47(s,2H,Ph-H),8.65(d,J=9.2Hz,2H,Ph-H).Massspectrometry(ESI-MS,m / z):[M] + calcd.for[C 34 H 30 N4Cl] + 529.2154; found: 529.2149.

[0069] Example 2 Synthesis of dye QC7-F

[0070]

[0071] 4.0 mmol of 7-fluoro-4-methylquinoline, 62.04 mmol of iodoethane, and 10 mL of acetonitrile were added to a 50 mL Shrek tube, and the reaction was carried out at 85 °C for 24 h under argon protection. After the reaction was completed, the acetonitrile solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane and methanol in a volume ratio of 99:1). After rotary evaporation, a bright yellow product, 7-fluoro-4-methylquinoline salt (660 mg, 2.08 mmol), was obtained, with a yield of 52%.

[0072] 1 H-NMR (400MHz, DMSO-d6, ppm): δ1.56 (t, J=7.2Hz, 3H, -CH3), 3.01 (s, 3H, CH3-Ph), 4.99 (q, J=7.2Hz, 2H, -CH2-N + ),8.01-8.07(m,2H,Ph-H),8.55(dd,J1=10.8Hz,J2=2.4Hz,1H,Ph-H),8.67(dd,J1=9.6Hz,J2=6.0Hz,1H,Ph-H),9.43(d,J=6.0Hz,1H,Ph-H). 19 F-NMR(376MHz,DMSO-d6,ppm):δ-99.03.Mass spectrometry(ESI-MS,m / z):[M] + calcd.for[C 12 H 13 NF] + 190.1008; found: 190.1032.

[0073]

[0074] 0.16 mmol of 7-fluoro-4-methylquinoline salt, 0.079 mmol of 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, 0.1 mL of piperidine, and 2 mL of anhydrous ethanol were added to a 50 mL Shrek tube. The tube was frozen with liquid nitrogen, deoxygenated three times under vacuum (100 Pa), and reacted at 90 °C for 24 h under argon protection. A precipitate formed after the reaction. The precipitate was filtered and washed with ultrapure water to remove salt, yielding a brown solid product: dye QC7-F (29 mg, 0.045 mmol), with a yield of 57%.

[0075] 1H-NMR (400MHz, DMSO-d6, ppm): δ1.39 (t, J=7.2Hz, 6H, -CH3), 1.86 (s, 2H, -CH2-), 2.79 (s, 4H ,-CH2-),4.42(q,J=6.4Hz,4H,-CH2-N),6.98(d,J=14.0Hz,2H,Alkene-H),7.38(d,J=7.2Hz ,2H,Ph-H),7.45-7.49(m,2H,Ph-H),7.81(dd,J1=11.2Hz,J2=2.4Hz,2H,Ph-H),7.99(d,J=1 3.6Hz, 2H, Alkene-H), 8.12 (d, J=7.2Hz, 2H, Ph-H), 8.59 (dd, J1=9.6Hz, J2=6.4Hz, 2H, Ph-H). 19 F-NMR (376MHz, DMSO-d6, ppm): δ-104.70. 13 C-NMR (100MHz, DMSO-d6, ppm): δ14.28,20.85,26.67,48.86,102.98(d,J C-F =27Hz), 109.64(d,J C-F =68Hz), 113.79, 114.72 (d, J) C-F =22Hz),122.08,127.24,128.61(d,J C-F =29Hz),136.03,139.38,141.12,142.03,145.28,162.94,165.43.Mass spectrometry(ESI-MS,m / z):[M] + calcd.for[C 32 H 30 N2ClF2] + 515.2060; found: 515.2058.

[0076] Example 3 Synthesis of dye QC7-CF3

[0077]

[0078] 0.43 mmol of 7-trifluoromethyl-4-methylquinoline, 8.52 mmol of iodoethane, and 8 mL of acetonitrile were added to a 50 mL Shrek tube, and the reaction was carried out at 85 °C for 24 h under argon protection. After the reaction was completed, the acetonitrile solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane and methanol in a volume ratio of 95:5). After rotary evaporation, a yellow product was obtained: 7-trifluoromethyl-4-methylquinoline salt (72 mg, 0.20 mmol), with a yield of 45%.

[0079] 1 H-NMR (400MHz, CDCl3, ppm): 2.75 (d, J=0.4Hz, 3H, -CH3), 7.36 (d, J=4.0Hz, 1H, Ph-H), 7.75 (dd, J1=8. 8Hz, J2=1.2Hz,1H,Ph-H),8.13(d,J=8.8Hz,1H,Ph-H),8.42(s,1H,Ph-H),8.88(d,J=4.4Hz,1H,Ph-H). 19 F-NMR (376MHz, CDCl3, ppm): δ-62.64. 13 C-NMR (100MHz, CDCl3, ppm): δ18.61,121.91,122.62,123.53(d,J C-F =8Hz),125.25,127.85,129.84,130.89(q,J C-F =32Hz),144.44,147.05,151.51.Mass spectrometry(ESI-MS,m / z):[M+H] +

[0080] calcd.for[C 11 H9NF3+H] + 212.0687; found: 212.0688.

[0081]

[0082] 0.14 mmol of 7-trifluoromethyl-4-methylquinoline salt, 0.068 mmol of 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, 0.1 mL of piperidine, and 2 mL of anhydrous ethanol were added to a 50 mL Shrek tube. The tube was frozen with liquid nitrogen, deoxygenated three times under vacuum (100 Pa), and reacted at 90 °C for 24 h under argon protection. A precipitate formed after the reaction. The precipitate was filtered and washed with ultrapure water to remove salt, yielding a brown solid product: dye QC7-CF3 (31 mg, 0.041 mmol), with a yield of 61%.

[0083] 1 H-NMR (400MHz, DMSO-d6, ppm): δ1.41 (t, J=6.8Hz, 6H, -CH3), 1.88 (s, 2H, -CH2-), 2.83(s,4H,-CH2-),4.55(q,J=6.4Hz,4H,-CH2-N),7.10(d,J=13.6Hz,2H,Alkene- H),7.48-7.50(m,2H,Ph-H),7.83(d,J=8.8Hz,1H,Ph-H),8.02(d,J=13.6Hz,1H,P h-H), 8.16 (s, 2H, Ph-H), 8.20 (d, J = 7.2Hz, 1H, Ph-H), 8.72 (d, J = 8.4Hz, 1H, Ph-H). 19 F-NMR(376MHz,DMSO-d6,ppm):δ-61.25.Mass spectrometry(ESI-MS,m / z):[M] + calcd.for[C 34 H 30 N2ClF6] + 615.1996; found: 615.1994.

[0084] Performance testing:

[0085] Dye QC7-CN from Example 1 and dye QC7-F from Example 2 were dissolved in analytical grade dimethyl sulfoxide to prepare 1 mM stock solutions of dye QC7-CN and dye QC7-F, respectively. 50 μL of dye QC7-CN stock solution and 50 μL of dye QC7-F stock solution were added to separate 5 mL volumetric flasks. The volumetric flask containing dye QC7-CN stock solution contained dimethyl sulfoxide, ethanol, and dichloromethane, while the volumetric flask containing dye QC7-F stock solution contained dimethyl sulfoxide, ethanol, and dichloromethane, respectively. After thorough mixing, the mixtures were transferred to quartz cuvettes (10 mm × 10 mm) to test the UV absorption and fluorescence emission spectra.

[0086] The UV absorption and fluorescence emission spectra of dye QC7-CN in dichloromethane in Example 1 are as follows: Figure 1 As shown, the UV absorption spectrum and fluorescence emission spectrum of dye QC7-F in dichloromethane in Example 2 are as follows: Figure 2 As shown. Figure 1 , Figure 2 It can be seen that the maximum absorption wavelength of QC7-CN is located at 1046 nm; when excited at 885 nm, the short-wave infrared emission wavelength of QC7-CN is located at 1075 nm, and its molar extinction coefficient is 2.1 × 10⁻⁶.5 M -1 cm -1 The maximum absorption wavelength of QC7-F is located at 975 nm; when excited at 885 nm, the short-wave infrared emission wavelength of QC7-F is located at 1003 nm, and its molar extinction coefficient is 2.51 × 10⁻⁶. 5 M -1 cm -1 .

[0087] The UV absorption and fluorescence emission spectra of dye QC7-CF3 in dichloromethane in Example 3 are as follows: Figure 3 As shown. Figure 3 It is known that the maximum absorption wavelength of QC7-CF3 is located at 1012 nm; when excited at 885 nm, the short-wave infrared emission wavelength of QC7-CF3 is located at 1040 nm, and its molar extinction coefficient is 2.45 × 10⁻⁶. 5 M -1 cm -1 .

[0088] Application Example 1: Short-wave infrared in vivo fluorescence imaging of quinoline cyanine short-wave infrared dyes in mice

[0089] All live experiments in this invention complied with the regulations for the breeding and use of laboratory animals and were approved by the Animal Breeding and Use Committee of East China University of Science and Technology. BALB / c nude mice (female, 4-6 weeks old) were purchased from Shanghai Slack Animal Experiment Co., Ltd., and were kept in sterile cages in a laminar flow fume hood in a sterile room, and fed with food and water that had been treated with high-pressure steam.

[0090] The dye QC7-CN (200 μM, 100 μL, dye encapsulated in DSPE-mPEG2000 liposome aqueous solution) from Example 1 was injected via the tail vein into BALB / c nude mice. Imaging was performed after injection with excitation light of 1064 nm, exposure time of 500 ms, and a filter of 1150 nm. Short-wave infrared fluorescence imaging of the dye QC7-CN from Example 1 in BALB / c nude mice is shown below. Figure 4 As shown, by Figure 4 The blood vessels and deep organs of the BALB / c nude mice can be clearly seen.

[0091] The dye described in this invention uses a quinoline heterocycle as the parent unit. By introducing an electron-withdrawing group at the 7-position of the quinoline ring, the absorption / emission wavelength, molar extinction coefficient, and luminescence intensity of the dye can be effectively controlled. Experiments show that the dye of this invention exhibits low absorption (high transparency) in the visible light region, while exhibiting strong absorption in the near-infrared and short-wave infrared regions. This dye is easy to modify structurally and has broad application prospects in fields such as building-integrated photovoltaics, night vision and intelligent security, and deep tissue fluorescence imaging.

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A visible-light transparent quinoline cyanine short-wave infrared dye, characterized in that, The quinoline unit has an electron-withdrawing group at position 7.

2. The visible-light-transparent quinoline cyanine short-wave infrared dye according to claim 1, characterized in that, The structural formula of the visible-light-transparent quinoline cyanine short-wave infrared dye is: Among them, R1 is independent: n is any integer from 1 to 20; R2 is independent of:

3. The method for preparing the visible-light-transparent quinoline cyanine short-wave infrared dye according to claim 1 or 2, characterized in that, It includes the following steps: 1) 4-methylquinoline compound, iodoethane and acetonitrile were reacted under a protective atmosphere to obtain 4-methylquinoline salt intermediate; 2) Mix 4-methylquinoline salt intermediate, 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt, piperidine and ethanol, and react the mixture under a protective atmosphere to obtain a visible-transparent quinoline cyanine short-wave infrared dye.

4. The preparation method according to claim 3, characterized in that, Step 1) The 4-methylquinoline compound comprises 7-fluoro-4-methylquinoline, 7-chloro-4-methylquinoline, 7-bromo-4-methylquinoline, 7-iodo-4-methylquinoline, 7-trifluoromethyl-4-methylquinoline, 7-cyano-4-methylquinoline, 7-sulfono-4-methylquinoline, or 7-nitro-4-methylquinoline; The structural formula of the 4-methylquinoline salt intermediate is: Among them, R1 is independent: n is any integer from 1 to 20.

5. The preparation method according to claim 3 or 4, characterized in that, The reaction temperature in step 1) is 80–90°C, and the reaction time is 22–26 h.

6. The preparation method according to claim 5, characterized in that, In step 1), the molar ratio of the 4-methylquinoline compound to iodoethane is 1:12-25; the molar volume ratio of the 4-methylquinoline compound to acetonitrile is 1 mmol:2-20 mL.

7. The preparation method according to claim 6, characterized in that, The reaction temperature in step 2) is 85–95°C, and the reaction time is 22–26 h.

8. The preparation method according to claim 6, characterized in that, In step 2), the molar ratio of the 4-methylquinoline salt intermediate to the 2-chloro-3-((phenylamino)methylenecyclohexen-1-yl)methyleneaniline salt is 0.12–0.2:0.06–0.09; the volume ratio of piperidine to ethanol is 0.08–0.12:1.5–2.

5. The molar volume ratio of 4-methylquinoline salt intermediate to piperidine is 0.12–0.2 mmol: 0.08–0.12 mL.

9. The application of the visible light transparent quinoline cyanine short-wave infrared dye as described in claim 1 or 2 in building-integrated photovoltaic technology, night vision imaging technology, and deep tissue fluorescence imaging technology.

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