• 대한화학회지
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• 제48권5호
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• pp.537-541
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• 2004

• 한국염색가공학회지
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• 제19권5호
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• pp.24-29
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• 2007

It is well known that certain classes of dye are reducible to stable colorless leuco compounds, which can be oxidized in air back to the colored species. We now reported that bis(4-dialkylaminophenyl)squaraine dyes are readily reduced in solution by borohydride to give alkali soluble leuco compound, which exists in the 3-hydroxy 2,4-bis(4-dialkylaminophenyl)cyclobuten-one. New alkylamine leuco compounds were synthesized by the reaction of leuco chloro-squaraine with alkylamine derivatives. The leuco compounds are easily isolated and can be air oxidized back to the squaraine dyes. These dyes have many technical application. e.g. in xerography, solar cell, optical recording material, redox indicators, and enzyme assays.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2003년도 춘계학술대회 논문집
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• pp.29-31
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• 2003

The 1,3-bis(4-aminoaryl)squaraines showed colour change behaviour, they were found to undergo reduction with sodium borohydride in solution to give colourless leuco compounds, which oxidised readily in air back to the coloured squaraine dye. We have shown that oxidation of the parent leuco-squaraines gives the neutral squaraine system. Initial observations indicated that the derivatives gave new long-wavelength absorbing chromophores, and It is interesting to note that the onidation of the leuco squaraines did initially produce a species absorbing at longer wavelengths than the parent squaraine dye. This colour-change redox behaviour has potential in the area of peroxidase-based bioassays and artificial camouflage.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.177-181
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• 2020

Dual-modality imaging strategy using near-infrared fluorescence (FLI) and photoacoustic imaging (PAI) demands a suitable probe to enable dual-modular signal production. Herein, we demonstrate a synthetic protocol of small molecular dye for dual-modular FLI and PAI. A condensation reaction between squaric acid and carboxypentyl benzoindolium, and followed by basic hydrolysis to give the benzoindole derived squaraine (BSQ) dye in 49% yield. Next, the carboxylic acid group of BSQ was further functionalized with N-hydroxysuccinimide or azide group for an efficient conjugation with a targeting biomolecule. BSQ showed a maximum fluorescent emission at around 680 nm and the photoacoustic signal reached a maximum intensity at 680-700 nm. Based on these results, we conclude that BSQ analogs will be useful probes for dual-modular (FLI/PAI) imaging studies in animal models.

• 한국염색가공학회지
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• 제18권5호
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• pp.53-60
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• 2006

The 1,3-bis(4-aminoaryl)squaraines showed color, change behavior, they were found to undergo reduction with sodium borohydride in solution to give colorless leuco compounds, which oxidized readily in air back to the colored squaraine dye. We have shown that initial observations indicated that the derivatives synthesized gave new donor-acceptor chromophores. It is also interesting to note than the oxidation of the leuco squaraines did initially produce a species absorbing about 630-680 wavelengths. The 1,3-squaraines have found many uses as near-infrared absorbers, laser dyes and photoconductive materials. Furthermore their color-change redox behavior has potential in the area of peroxidase-based bioassaysas oxidation sensitive indicator systems were investigated.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 춘계 학술발표 강연 및 논문 개요집
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• pp.142-142
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• 1994

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.428-432
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• 2005

Squarylium or squaraine dyes are derived from 1,2-dihydroxycyclobuten-3,4-dione, otherwise known as squaric acids. They are two principal types: the 1,2-bisdonorsubstituted derivatives, and the 1,3-bisdonorsubstituted derivatives. The former are essentially merocyanines and have no distinctive properties, whereas the latter represent a unique type of chromophore, which is neither a merocyanines nor cyanine and has exceptional light absorption characteristics. They also have many functional applications based on their special properties. Thus it was the objective of this research project to synthesize a range of 1,3-squarylium dyes of widely differing structural types, and to investigate their light absorption and fluorescence properties in general, and the color change properties of appropriate examples in particular. Also in this study, the various pHinduced colour change processes were examined.

• 대한전자공학회논문지SD
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• 제37권6호
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• pp.17-23
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• 2000

본 연구에서는 Sq색소를 이용하여 적색발광의 디바이스를 제작하고, 발광효율을 증가시키기 위해 OXD7과 $Alq_3$층을 발광층과 음극사이에 삽입하여 그 효과를 관측하고, 기구특성을 검토하였다. 정공운송층으로서 TPD, 발광층 호스트재료로서 $Alq_3$, 게스트 재료로서 Sq를 사용하였다. 그 결과 $Alq_3$층의 삽입은 효율을 증가시킬 수 있었지만, 삽입된 $Alq_3$층에서의 발광 때문에 색순도 높은 적색발광을 얻지 못했다. OXD7층의 삽입은 정공을 블로킹하고 정공을 누적시킨다. 이는 전자와 정공의 재결합확률을 증가시키기 때문에 색순도 높은 적색발광을 유지하면서 휘도 특성과 발광효율이 향상되었다.