Syntheses And Properties Of Some Novel Derivative Of Metal Borates

Metal borates have attracted much attention during in the past decades because of their abundant structural c hemistry,excellent thermal and chemical stabilitie s,wide band gap and transparent regions,and high possibility for noncentro symmetric corrpounds.After decades of explorations,abundant metal borates with excellent physical properties have been reported.They have broad applications in nonlinear optical,magnetic and luminescence materials,etc.Thus,this thesis mainly focused on the explorations for novel metal borates.First,the ?-conjugated organic anions have been incorporated into borates to obtain mixed anions borates.We can not only greatly increase the probability to obtain NCS materials but also enhance SHG responses through the synergistic polar effect in them of both types of SHG-active groups.On the other hand,SO4 units were introduced into borate systems to synthesize novel borate-sulfates.Based on the above assunptions,we apply both hydrothermal method and high temperature solid state reaction to explore new borates.The results are as the following:(1)Eight novel tartratoborates,namely,Bat[H(C4H2O6)2B](H2O)(1)?Pb2[H(C4H2O6)2B](H2O)(2)?Cd5[(C4H2O6)2B]2(H2O)8·4H2O(3)KCo2[(C4H2O6)2B](H2O)3(4)?KNi2[(C4H2O6)2B](H2O)2.5(5)K2Cd4[(C4H2O6)2B]2(H2O)2(6)?Li0.91K1.09Cd1.5[(C4H2O6)2B](H2O)2(7)and Cd3Pb2[(C4H2O6)2B]2(H2O)6(8)have been successfully synthesized by hydrothermal method.In the structure of these compounds,one BO4 group condensed with two tartrate ions to form a novel[(C4H2O6)2B]5-anion group,which then chelates with various metal ions in different ways to form many types of structures.Among these eight compounds,magnetic measurements of compounds 4 and 5 revealed a dominant antiferromagnetic interaction between neighboring metal ions,whereas compounds 6 and 7 exhibit SHG response of approximately 3.2 and 1.5 times that of KDP,respectively.(2)Since Pb2+ and Bi3+ have lone pair electrons and exhibit diversity of coordination modes,we introduced Pb2+ and Bi3+ into borate-sulfates,Pb2[(BO2)(OH)](SO4)(9)and BbPb3O4(BO3)(SO4)2(10)were obtained by hydrothermal methods and high temperature solid state reaction,respectively.In Pb2[(BO2)(OH)](SO4)(9),the lead(?)ions are interconnected by borate and sulfite anions into 2D Pb-B-O and Pb-S-O layers parallel to the ab plane,respectively,and these layers are further condensed into the 3D lead(?)borate-sulfate framework.BbPb3O4(BO3)(SO4)2(10)crystallizes in space group Cmcm.In Bi3Pb3O4(BO3)(SO4)2,the one-dimensional Pb-O-Bi chains are bridged by BO3 groups into a two-dimensional layered structure.These two-dimensional layers are then inter connected bridging through SO4 groups to form a three-dimensional structure.