title: Facile Syntheses of Ba2[B4O7(OH)2] and Na[B5O7(OH)2](H2O) Borate Salts Exhibiting Nonlinear Optical Activity in the Ultraviolet.
abstract: Two novel noncentrosymmetric metal borates, Ba2[B4O7(OH)2] (1) and Na[B5O7(OH)2](H2O) (2), have been obtained by hydrothermal and surfactant-thermal means. Compound 1 consists of novel one-dimensional borate chains formed by B3O9and B3O8rings, assembled into a three-dimensional (3D) framework by Ba2+cations. The structure of 2 exhibits double-helical chains constructed from B5O10primary building units, which are interconnected via Na+cations and H-bonding interactions to generate a 3D framework. Second-harmonic-generation (SHG) measurements show that 1 shows a phase-matching powder SHG response of ∼2.2 × KH2PO4(KDP), while 2 exhibits a weak SHG response. The cutoff edges of 1 and 2 are ∼242 and ∼221 nm, respectively, which suggests that they are potential ultraviolet nonlinear optical (NLO) materials. Band structures and NLO properties have also been theoretically studied.
authors.affiliation: School of Chemical Science and Engineering, Tongji University , Shanghai 200092, P. R. China.|School of Chemical and Material Engineering, Jiangnan University , Wuxi 214122, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.affiliation: China-Australia Joint Research Center for Functional Molecular Materials, Jiangsu University , Zhenjiang 212013, P. R. China.
authors.forename: Longhua
authors.initials: L
authors.lastname: Li
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University , Wuxi 214122, P. R. China.
authors.forename: Junling
authors.initials: J
authors.lastname: Song
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University , Wuxi 214122, P. R. China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Mark G
authors.identifier: http://orcid.org/0000-0002-4433-6783
authors.initials: MG
authors.lastname: Humphrey
authors.affiliation: School of Chemical Science and Engineering, Tongji University , Shanghai 200092, P. R. China.|Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Shanghai 201800, P. R. China.|Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Chi
authors.identifier: http://orcid.org/0000-0002-5237-8916
authors.initials: C
authors.lastname: Zhang