Two Non-π-Conjugated Deep-UV Nonlinear Optical Sulfates

Abstract

The non-π-conjugated sulfate system has long been overlooked as potential deep-UV nonlinear optical (NLO) materials. Here we report two asymmetric anhydrous sulfates, namely, NH 4 NaLi 2 (SO 4 ) 2 (Ι) and (NH 4 ) 2 Na 3 Li 9 (SO 4 ) 7 (Π), which consist of non-πconjugated [SO 4 ] 2− anions. Their single crystals can be readily grown by a facile evaporation method from water solution. Both sulfates are transparent down to the deep-UV region. Interestingly, there is a large NLO gap between I and Π, with phase-matching NLO responses of 1.1 and 0.5 times that of the benchmark KH 2 PO 4 , respectively. The first-principles studies reveal that the non-π-conjugated [SO 4 ] 2− anions are the dominate NLOactive groups, and the large NLO gap between I and Π can be ascribed to the nonbonding O 2p orbitals of different orientations in the crystallographically independent S1O 4 groups. This work provides an innovative non-πconjugated source that is distinct from the traditional πconjugated ones for deep-UV NLO materials.

Sb6O7(SO4)2: A Promising Ultraviolet Nonlinear Optical Material with an Enhanced Second‐Harmonic‐Generation Response Activated by SbIII Lone‐Pair Stereoactivity

“…A major reason may be that sulfates are difficult to synthesize because they are unstable and tend to release the poisonous gas SO 3 at high temperature. Another reason is that sulfates are also not easily achieved through a facile aqueous‐based approach due to the low solubility of most sulfates [31, 32] . Hence, exploring an approach for the generation of sulfates is important.…”

Lead Mixed Oxyhalides Satisfying All Fundamental Requirements for High‐Performance Mid‐Infrared Nonlinear Optical Materials

“…Subsequently,a ne xtensive exploration has been performed systematically in borates, [10] fluorooxoborates, [11] carbonates, [12] nitrates, [13] phosphates, [14] fluorophosphates, [15] silicates, [16] cyanurates, [17] and sulfates. [18] By doing so,quite afew candidates for UV/DUV NLO materials have been discovered. [19] Meanwhile,an umber of recently reported crystals with outstanding properties such as Pb 2 BO 3 Cl, [20] Cs 3 VO-(O 2 ) 2 CO 3 , [21] Bi 3 Te BO 9 , [22] APbCO 3 F( A = Rb,C s), [23] and BiFSeO 3 [24] should be good candidates as visible/near-IR NLO materials.Incontrast, in the mid-IR region (2.0-20 mm), af ew NLO materials such as AgGaS 2 , [25] AgGaSe 2 , [25] and ZnGeP 2 [26] are commercially available to date.However,they all suffer from some demerits such as low LDT and difficulty in crystal growth.…”

Synthesis, Crystal Structure, and Characterization of a Noncentrosymmetric Sulfate Cs2Ca2(SO4)3

“…The represent examples include phosphates such as A La(PO 3 ) 4 ( A = K, Cs), RbBa 2 (PO 3 ) 5 , Li A 2 PO 4 ( A = Rb, Cs), A 4 Mg 4 (P 2 O 7 ) 3 ( A = K, Rb), A NaMgP 2 O 7 ( A = Rb, Cs), and Ba 2 NaClP 2 O 7 ; silicates such as Cs 2 B 4 SiO 9 and CsSiB 3 O 7 ; fluorooxoborate such as A B 4 O 6 F ( A = Na, Cs, NH 4 ) and M 2 B 10 O 14 F 6 ( M = Ca, Sr); fluorophosphates such as Na(NH 4 )PO 3 F · H 2 O and (NH 4 ) 2 PO 3 F . Due to the easy synthesis route, some short‐wave UV NLO sulfates, such as A SbF 2 SO 4 ( A = Rb, Cs), (NH 4 ) 2 Na 3 Li 9 (SO 4 ) 7 , (NH 4 )NaLi 2 (SO 4 ) 2 , and Li 8 NaRb 3 (SO 4 ) 6 · 2H 2 O, were prepared using the aqueous or ionic solution method. However, these NLO sulfates suffer from weak stability during heating.…”