Unprecedented Deep Ultraviolet (DUV) Birefringence in Fluorides Constructed from Linear π-Group Anisotropic Structure Building Units

Meng-Yue Li; Xin Liu; Yi-Chen Liu; Rui-Xi Wang; JingYu Guo; Li-Ming Wu; Ling Chen

doi:10.1002/anie.202423054

Unprecedented Deep Ultraviolet (DUV) Birefringence in Fluorides Constructed from Linear π-Group Anisotropic Structure Building Units

Angew Chem Int Ed Engl. 2024 Dec 23:e202423054. doi: 10.1002/anie.202423054. Online ahead of print.

Authors

Meng-Yue Li¹, Xin Liu², Yi-Chen Liu¹, Rui-Xi Wang¹, JingYu Guo¹, Li-Ming Wu³, Ling Chen⁴

Affiliations

¹ Beijing Normal University, college of chemistry, CHINA.
² Beijing Normal University, college of chemistry, Xinjiekou Waidajie, 100875, Beijing, CHINA.
³ Beijing Normal University, college of chemistry, Xinjiekou Waidajie, Beijing, CHINA.
⁴ Beijing Normal University, chemistry department, xinjiekou waidajie num 19, 100875, Beijing, CHINA.

PMID: 39714557
DOI: 10.1002/anie.202423054

Abstract

Advancing laser technologies requires maximizing the anisotropy of crystalline media and overcoming current birefringence limitations. We introduce the strategy of linear π group anisotropic structure building units (ABUCB), leading to an unprecedented large birefringence (Δn), a record-high Δnobv. of 0.152 in sodium bis(dicyanoborato)fluoride (Na[BF2(CN)2]), the highest reported among deep ultraviolet (DUV) materials. This value is 35 % greater than state-of-the-art α-BBO and 1167 % greater than MgF2. Density functional theory analyses suggest that the linear π group enhances bulk optical anisotropy and ensures a shorter DUV absorption edge. These results establish Na[BF2(CN)2] as a groundbreaking DUV birefringent material and open new avenues for research into extending π groups and exploring additional possibilities.

Keywords: Birefringence; Cyanogroup; Deep ultraviolet; Linear π-group.