KR-102963433-B1 - HUGE BIREFRINGENT MATERIAL INCLUDING LINEAR BLOCKS

Abstract

The present invention relates to a novel linear birefringent active group exhibiting high birefringence and a birefringent material containing the same.

Inventors

• 옥강민
• 진숭안

Assignees

• 서강대학교산학협력단

Dates

Publication Date

20260508

Application Date

20250604

Claims (11)

1. Linear birefringent active group (IX 1 2 ) and As a compound containing a cation (A), A birefringent material comprising an asymmetric unit represented by the following chemical formula 1 or the following chemical formula 2: [Chemical Formula 1] [A][IX 1 2 ]; [Chemical Formula 2] [A] 2 [IX 1 2 ]·X 2 ; In the above chemical formulas 1 and 2, X1 and X2 are each independently halogen elements.
2. In Article 1, A birefringent material in which the above cation is protonated 4-aminopyridine or protonated dimethylamine.
3. In Article 1, A birefringent material in which the halogen elements X1 and X2 are each independently Cl or Br.
4. In Article 1, The above birefringent material is a birefringent material synthesized by a slow evaporation process.
5. In Article 1, A birefringent material having a birefringent value of 0.5 or more at 400 nm to 700 nm.
6. In Article 1, A birefringent material having a birefringent value of 0.3 or higher at 700 nm to 2500 nm.
7. In Article 1, A birefringent material having a band gap of 3.0 eV or more at 380 nm to 740 nm.
8. In Article 1, The birefringent material represented by the above chemical formula 1 is a triclinic space group That which crystallizes in, Birefringent material.
9. In Article 1, The birefringent material represented by the above chemical formula 1 is, The above birefringent active group and the above cation each form a parallel arrangement, and The above birefringent active group and the above cation have a structure in which they interact with each other via hydrogen bonding. Birefringent material.
10. In Article 1, The birefringent material represented by the above chemical formula 2 is one that crystallizes in the monoclinic space group P2 / c , Birefringent material.
11. In Article 1, The birefringent material represented by the above chemical formula 2 is, The above cation (A) and halogen anion ( X₂ ) form a chain by hydrogen bonding, and A structure in which the birefringent active group (IX 1 2 ) is located between the above chains, Birefringent material.

Description

HUGE BIREFRINGENT MATERIAL INCLUDING LINEAR BLOCKS The present invention relates to a novel linear birefringent active group exhibiting high birefringence and a birefringent material containing the same. Birefringent crystals are a group of materials characterized by significant optical anisotropy that can alter the direction of light propagation, modulate the phase of light, and even achieve frequency conversion under specific conditions , thereby promoting the advancement of laser technology. Although various birefringent crystals such as MgF₂ , α- BaB₂O₄ (α-BBO), CaCO₃ , and TiO₂ have been commercially applied, their birefringent values (△α) were limited to less than 0.3. Only recently have several birefringent crystals been discovered through in-depth research, but only a few materials exhibited large birefringents. The development of novel birefringent crystals with large birefringents remains a key and important task in the advancement of optical device technology. In the design and synthesis of birefringence crystals, two critical factors affecting birefringence are optical anisotropy ( △ α) and the spatial arrangement of birefringence-active groups (BAGs). At the current stage , the most studied BAGs are π-conjugated groups with delocalized electrons, specifically, systematic studies are being conducted on π-conjugated BAGs such as the six -membered ring B₃O₆³⁻ , [H x C₃N₆O₆ ]( 3 -x)⁻ (where x = 0 to 3), C₃N₆H₇⁺ , and C₆O₆ . In addition, actively studied BAG types include stereochemically active lone pair groups. These groups possessing lone pairs are characterized by exhibiting strong polarization anisotropy, examples of which include SnPO₄I ( △n exp = 0.664 @ 546 nm), Mo( H₂O ) Te₂O₇ ( △n exp = 0.528 @ 546 nm ) , Hg₄ ( Te₂O₅ )( SO₄ ) ( △n exp = 0.542 @ 546 nm), and ( C₅H₆₆N₂Cl₀.84 )( IO₂Cl₂ ) ( △ n exp = 0.67 @ 550 nm). In addition to achieving large optical anisotropy , optimizing the spatial arrangement of the BAG is also important. According to prior research on cyanurates, it has been confirmed that the non-planar configuration and non-parallel spatial arrangement of BAGs can partially weaken polarization anisotropy. Consequently, linear molecules have emerged as promising candidate materials in the BAG family over the past few years, but research on them remains limited. The unique linear structure of linear molecules imparts a large △α. However, due to the difficulties associated with constructing and isolating linear groups , experimental studies are lacking, and most research on linear BAGs currently remains at a theoretical level. Studies to date have confirmed that highly anisotropic linear polysulfide anions ( S₂²⁻ ) significantly influence the birefringence observed in Na₂S₂ ( △n cal = 0.52 @ 1064 nm) and BaS₂ ( △n cal = 0.47 @ 1064 nm). Similarly, linear BN²⁻ anions have also been identified as promising BAG candidate materials through theoretical calculations. FIGS. 1a to 1g are structural diagrams of Compound 1 and Compound 2 prepared according to Example 1 of the present invention, respectively, of a linear birefringent active group ([ICl 2 ] - , FIG. 1a), protonated 4-aminopyridine ([H-4AP] + , FIG. 1b), a π-π stacking structure between [H-4AP] + included in Compound 1 (Fig. 1c), a spatial arrangement of [ICl 2 ] - and [H-4AP] + included in Compound 1 (Fig. 1d), a structure of a supramolecular chain formed by protonated dimethylformamide and Cl - ([HDMA] + , FIG. 1e), [HDMA] + and Cl - included in Compound 2 (Fig. 1f), and a spatial arrangement of [ICl 2 ] - and said supramolecular chain included in Compound 2 (Fig. 1g). FIGS. 2a to 2l are images of compounds 1 to 4 prepared according to Example 1 of the present invention taken with a polarizing microscope, and from the top, crystal images taken under cross-polarized light (2a to 2d), crystal images with complete extinction of birefringence (2e to 2h), and images showing the thickness of the crystals (2i to 2l). FIGS. 3a to 3k are drawings or graphs describing the characteristics of compounds 1 to 4 prepared according to Example 1 of the present invention, respectively, the theoretical birefringence values of compounds 1 to 4 (Fig. 3a), the unit sphere representation of the polarization degree of ICl 2- under a static electric field (Fig. 3b), the angle between [IX 2 ] - and [H-4AP] + contained in compounds 1 and 3 (Fig. 3c), the real-space atom cutting analysis graphs performed at 546 nm and 1064 nm for compound 1 (Figs. 3d and 3e), the real-space atom cutting graphs performed at 546 nm and 1064 nm for compound 3 (Figs. 3f and 3g), and the partial density of states (PDOS) and total density of states (TDOS) diagrams for each of compounds 1 to 4 (Figs. 3h to 3k). Figure 4 is a graph comparing the polarization anisotropy of the birefringent active group (ICl 2- , IBr 2- ) of the present invention with that of other iodic acid-derived BAGs and widely studied planar π-conjugated birefringent active groups. FIG. 5a is a graph comparing