RESUMO
Inorganic adducts are an emerging class of infrared nonlinear optical (NLO) materials. However, although the reported NLO adducts have sufficient birefringences and significant laser-induced damage thresholds (LIDTs), they commonly suffer from weak second harmonic generation (SHG) responses. In this work, a series of polar phosphorus chalcogenide cage molecules with strong hyperpolarizabilities were theoretically screened out to enhance the SHG responses of adducts. Accordingly, (CuI)3 (P4 S4 ), (CuI)3 (P4 Se4 ), (CuBr)7 (P4 S3 )3 and (CuBr)7 (P4 Se3 )3 with target polar cage molecules were successfully synthesized. As expected, they exhibit enhanced SHG responses while keeping moderate birefringences and high LIDTs. Notably, (CuBr)7 (P4 Se3 )3 possesses the largest SHG response (3.5×AGS@2.05â µm) among the known inorganic NLO adducts. Our study confirms that introducing NLO-active cage molecules into adducts is an efficient strategy for high-performance NLO materials.
RESUMO
We herein report two asymmetric germanate crystals, KNbGe3 O9 and K3 Nb3 Ge2 O13 , with different structures and optical properties derived from divergent polymerized forms of GeO4 and NbO6 groups. Remarkably, K3 Nb3 Ge2 O13 achieved a rare combination of the strongest second harmonic generation (SHG) response of 17.5×KDP @ 1064â nm and the largest birefringence of 0.196 @ 546â nm in germanates. It features unique [Nb3 O12 ]∞ tubular chains constructed by circular Nb3 O15 tripolymers. Theoretical calculations reveal that the d-p interactions in the Nb3 O15 group are responsible for outstanding optical properties. This work emphasizes the significance of the polymerizable functional units in obtaining high-performance nonlinear optical (NLO) crystals.
RESUMO
To obtain new nonlinear optical (NLO) materials with a large second harmonic generation (SHG) effect has always been a great challenge. We have synthesized the first metal borate-iodate NLO crystal, Be2 (BO3 )(IO3 ) (BBIO), by multicomponent modification of KBe2 BO3 F2 (KBBF), in which the structural features of KBBF were maintained and (IO3 )- groups were connected to honeycomb [Be2 BO3 O2 ]∞ layers. As the first KBBF family member with mixed anionic groups, BBIO benefited from the synergistic effect of (IO3 )- , (BO3 )3- and (BeO4 )6- groups, and exhibited a very strong SHG response of ≈7.2×KH2 PO4 (KDP, @1064â nm) and a large birefringence (Δn) of 0.172 at 1064â nm. BBIO may, unexpectedly, optimize growth habits via van der Waals forces. This study presents borate-iodate as a new NLO material and it demonstrates opportunities in KBBF structural engineering.
RESUMO
An alkaline-earth-metal iodate fluoride, Ba(IO3)F (1), was discovered by introducing F atoms into alkaline-earth-metal iodates via a hydrothermal method. The pseudo-two-dimensional (2D) [BaF]+ layers and [IO3]- anionic groups built the crystal structure, which obviously exhibited large anisotropies. The birefringence of 1 was initially tested to be 0.1256 at 589.3 nm. Besides, compared with most reported metal iodate crystals, 1 possesses a large band gap (Eg = 4.32 eV). Theoretical calculations proved that the excellent optical characteristics can be attributed to [IO3]- anionic groups and [BaO4F4]10- polyhedra.
RESUMO
An ammonium-containing metal iodate fluoride compound, (NH4 )Bi2 (IO3 )2 F5 , featuring a two-dimensional double-layered framework constructed by [BiO2 F5 ]6- and [BiO4 F4 ]9- polyhedra, as well as [IO3 ]- groups, was successfully synthesized. The well-ordered alignment of these SHG-active units leads to an extraordinary strong SHG response of 9.2 times that of KDP. Moreover, this compound possesses a large birefringence (Δn=0.0690 at 589.3â nm), a wide energy band gap (Eg =3.88â eV), and a high laser damage threshold (LDT; 40.2×AgGaS2 ). In particular, thermochromic behavior was observed for the first time in this type of compound. Such multifunctional crystals will expand the application of nonlinear optical materials.
RESUMO
BACKGROUND: In recent years, inductively coupled plasma mass spectrometry (ICP-MS) has been widely used in the field of molecular biology because of its unique advantages. Anthrax is a widespread and long-standing infectious disease, which affects and restricts people's work and life seriously. OBJECTIVE: The study goal is to develop a new method for the detection of anthrax. METHODS: A rapid, sensitive and accurate method for the detection of anthrax characteristic DNA was proposed by combing gold nanoparticles (AuNPs) and inductively coupled plasma mass spectrometry. RESULTS: The linear range of this method is 100-2500 pmol/L and the limit of detection of 16.61 pmol/L. CONCLUSION: The proposed method has numerous advantages, including simplicity of operation, high sensitivity, and specificity, which provides a new idea for the detection of anthrax. Importantly, this methodology has good potential for the detection of other biological substances such as bacteria and viruses by changing the modification sequence on the nanoparticle probe.
Assuntos
Antraz , Nanopartículas Metálicas , Humanos , Ouro/química , Espectrometria de Massas/métodos , Nanopartículas Metálicas/química , Antraz/diagnóstico , DNA/análise , DNA/química , DNA/genéticaRESUMO
Two unprecedented metal borate-iodates, Sr[B(OH)4](IO3) (SBIO) and Li4Sr5[B12O22(OH)4](IO3)2 (LSBIO), were synthesized via the strategy of introducing (IO3)- into borates. In particular, the LSBIO possessed a new B12O26 fundamental building block (FBB). The two compounds integrated the advantages of both pure iodates and borates, showing enlarged band gaps and birefringence. Moreover, diverse B-O FBBs achieved the modulation of birefringence. This work reported the first two examples of borate-iodates.