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A new polar compound Pb 2 (SeO 3 )(NO 3 ) 2 was synthesized by the conventional facile hydrothermal method at middle temperature 200 °C and characterized by X-ray single crystal diffraction, powder diffraction, UV–vis−NIR optical absorption spectrum and infrared spectrum. It crystallizes in the orthorhombic system, space group Pmn 2 1 with a = 5.4669(3) A, b = 10.3277(6) A, c = 7.2610(4) A, V = 409.96(4) A 3 . The compound features a 2D [Pb 2 (SeO 3 )] 2 ∞ architectures composed of SeO 3 and PbO 2 /PbO 3 units. Two unequivalent N(1)O 3 and N(2)O 3 units is inserted between adjacent [Pb 2 (SeO 3 )] 2 ∞ layers to stabilize the whole crystal structure. Second-harmonic generation (SHG) efficiency has been evaluated for powder Pb 2 (SeO 3 )(NO 3 ) 2 samples, showing about 2 times that of KDP reference. Moreover, the compound can achieve I-type phase-matching according to measurements by the Kurtz–Perry method. Theoretical investigations based on the first-principle DFT method were also performed to gain further insights into the crystal structure and optical properties relationship. The calculated band gap value of 3.38 eV is consistent with the optical reflectance measurements value of 3.76 eV. |
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