Two pure mixed alkali metal borates with Non-Linear Optical (NLO) properties, Li 6 Rb 5 B 11 O 22 and Li 4 Cs 3 B 7 O 14 , have been synthesized by a high-temperature solid state reaction, and characterized by XRD, FT-IR, DTA-TG techniques and chemical analysis. The molar enthalpies of solution of Li 6 Rb 5 B 11 O 22 and Li 4 Cs 3 B 7 O 14 in 1 mol · dm −3 HCl (aq), and of LiCl·H 2 O(s) in (1 mol · dm −3 HCl + H 3 BO 3 + RbCl/CsCl) (aq) have been determined by microcalorimeter at T = 298.15 K, respectively. From these data and with the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol · dm −3 HCl (aq), together with the use of the standard molar enthalpies of formation for LiCl·H 2 O(s), RbCl(s)/CsCl(s), H 3 BO 3 (s), HCl(aq) and H 2 O(l), the standard molar enthalpies of formation of −(11173.1 ± 9.5) kJ · mol −1 for Li 6 Rb 5 B 11 O 22 and −(7145.1 ± 5.9) kJ · mol −1 for Li 4 Cs 3 B 7 O 14 were obtained on the basis of the appropriate thermochemical cycles.
Min Wan,Yan-Ning Wang,Wen-He Zhong,Hao-Ran Chen,Zi-Mu Li,Cai-Hong Shi,Qing-Ling Cao,Jie-Yu Zhu,Li-Zhuang Chen
In the realm of optical and quantum computing, second-harmonic generation (SHG) serves as a valuable nonlinear optical element for both optical signal processing and quantum information processing. Herein, we report a series of innovative nonlinear optical (NLO) materials, denoted as (4-F-BTAB)ReO4, (4-Cl-BTAB)ReO4, and (4-Br-BTAB)ReO4 (BTAB = para-halobenzyltrimethylammoniun), which show illustrious high-contrast “off-on–off” SHG conversion over a broad temperature range. The precise halogen modification of cations not only achieves significant SHG signal intensity (1.08 × KDP–3.23 × KDP) but also elevates phase transition temperatures from 415.5 to 474.4 K. Notably, (4-Br-BTAB)ReO4 demonstrates a heightened SHG-active state with an increase of nearly 60 K, along with a wide band gap of 3.646 eV and enhanced piezoresponse performance of 2.25 V. This study contributes to the diversification of switchable NLO materials.
危险品化学品经营许可证（带存储）