Rational Design of the Metal‐Free KBe₂BO₃F₂⋅(KBBF) Family Member C(NH₂)₃SO₃F with Ultraviolet Optical Nonlinearity

Abstract

The first fluorosulfonic ultraviolet (UV) nonlinear optical (NLO) material, C(NH2)3SO3F, is rationally designed by taking KBe2BO3F2 (KBBF) as the parent compound. C(NH2)3SO3F features similar topological layers as KBBF by replacing inorganic (BO3)3− with organic C(NH2)3+ trigonal units and BeO3F with SO3F− tetrahedra. Therefore, C(NH2)3SO3F is a metal‐free UV NLO crystal. Benefiting from the coplanar configuration of the C(NH2)3+ cationic groups, it possesses a large SHG response of 5×KDP and moderate birefringence of 0.133@1064 nm. Besides, it has a short UV cutoff edge of 200 nm. The calculated results reveal the shortest SHG phase‐matching wavelengths can reach 200 nm. These findings highlight the exploration of metal‐free compounds as nontoxic and low‐cost UV NLO materials as a new research area.

AZn2(BO3)Si2O5 (A = Rb, Cs): first examples of KBe2BO3F2 structure type in the borosilicate family exhibiting a deep-ultraviolet cutoff edge

“…Recent success in the KBBF template-based group UV NLO crystal design is well manifested in fluorooxoborates, 43,44 among which NH 4 B 4 O 6 F, 45 CsB 4 O 6 F, 46 are highly regarded as plausible alternatives to KBBF. To date, several KBBF type inorganic borate derivatives, as well as mixed anionic group NLO crystals with an impressive optical performance, have been discovered, such as Pb 2 BO 3 I, 36 Be 2 (BO 3 )(IO 3 ), 37 AZn 2 BO 3 X 2 (A = K, Rb, NH 4 ; X = Cl, Br), 47 K 2 Sb(P 2 O 7 )F, 48 NaZnCO 3 (OH), 49 C(NH 2 ) 3 SO 3 F 50 and so forth. Recently, the KBBF type birefringent crystal Sn 2 PO 4 I, 51 with an outstandingly large birefringence (0.466 at 1064 nm) was also designed.…”

Variable dimensionality of the anion framework in four new borophosphates and fluoroborophosphates with short cutoff edges

“…with improved optical performances. [19][20][21][22][23][24][25][26][27][28][29][30][31] Notable examples include Li 2 B 6 O 9 F 2 , 32 M I B 4 O 6 F (M I = Na, K, Rb, Cs and NH 4 ), [33][34][35][36] M II B 5 O 7 F 3 (M II = Mg, Ca, and Sr), [37][38][39] M II B 2 O 3 F 2 (M II = Pb, and Sn) 40,41 and M I BPO 4 F (M I = NH 4 , K, Rb, and Cs). [42][43][44][45] Based on the above idea, we obtained four new crystals including two borophosphates and two fluoroborophosphates after exploration in the A-B-O-P-F (A = alkali metal or NH with a ratio of 3 : 1 was placed into the platinum crucible after thorough grinding.…”

[C3N6H7]2[B3O3F4(OH)]: a new hybrid birefringent crystal with strong optical anisotropy induced by mixed functional units

“…4 In order to achieve a large birefringence, several approaches corresponding to the modification of cationic and anionic units have proved to be effective. 5–9 For cationic units, the introduction of early transition metal cations with d 0 configurations and rare earth metal cations can lead to the formation of metal-centered distorted polyhedra, which thereby enhance the optical anisotropy. 5 In addition, highly polarized d 10 cations as well as Pb 2+ , Sn 2+ , Bi 3+ , and Sb 3+ cations with stereochemically active lone pairs (SCALPs) can induce large anisotropic polarizability.…”

“…8 d Fluorinated covalent tetrahedra, however, have also been utilized to design birefringent materials due to their improved microscopic properties compared to those of their fully oxidized counterparts, as evidenced by the emergent fluorooxoborates, fluorophosphates, and other fluorinated systems. 9…”