五硼酸钾溶液中含硼物种的研究  

Boron-11 Nuclear Magnetic Resonance Study of Aqueous Potassium Pentaborate Solution

作　　者：贾力凡 朱发岩[1,2] 周永全 刘红艳[1,2] 王云霞 王广国[1,2,3] 景转芳 宋露露 JIA Li-fan;ZHU Fa-yan;ZHOU Yong-quan;LIU Hong-yan;WANG Yun-xia;WANG Guang-guo;JING Zhuan-fang;SONG Lu-lu(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resouces,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008,China;Key laboratory of Salt Resources and Chemistry,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008,China;Graduate University of Chinese Academy of Sciences,Beijing,100049,China)

机构地区：[1]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海西宁810008 [2]青海省盐湖资源化学重点实验室,青海西宁810008 [3]中国科学院大学,北京100049

出　　处：《盐湖研究》2022年第4期110-117,共8页Journal of Salt Lake Research

基　　金：青海省“高端创新人才计划”(培养拔尖人才)项目;国家自然科学联合基金项目(U1607106)。

摘　　要：采用物种分布图与核磁共振实验研究了五硼酸钾溶液中含硼物种的类型、含量和溶液浓度间关系。研究表明五硼酸钾在稀溶液(0.05 mol/kg(H_(2)O))中几乎全部水解,主要物种为B(OH)_(3)和B(OH)_(4)^(-);在较浓溶液(0.20 mol/kg(H_(2)O))中主要物种为B(OH)_(3)和B_(3)O_(3)(OH)_(4)^(-),而B_(5)O_(6)(OH)_(4)^(-)和[B_(4)O_(5)(OH)_(4)^(2-)]的含量较小。核磁共振实验研究给出了B(OH)_(4)^(-)、B_(3)O_(3)(OH)_(4)^(-)和B_(5)O_(6)(OH)_(4)^(-)的生成常数K_(1)、K_(3),、K_(5),研究得出B_(5)O_(6)(OH)_(4)^(-)含量很少的原因是其解聚为其它类型硼酸根离子。外加离子促进五硼酸根离子的生成,而高温条件促进B_(5)O_(6)(OH)_(4)^(-)发生解聚反应。The relationship between the type,content and solution concentration of boron-containing species in potassium pentaborate solution was studied using species distribution diagrams and NMR experiments.Studies have shown that potassium pentaborate is almost completely hydrolyzed into B(OH)_(3)and B(OH)_(4)^(-)in dilute solution(0.05 mol/kg(H_(2)O)).The main species in the concentrated solution(0.20 mol/kg(H_(2)O))are B(OH)_(3)and B_(3)O_(3)(OH)_(4)^(-),while the content of B_(5)O_(6)(OH)_(4)^(-)and[B_(4)O_(5)(OH)_(4)^(2-)]is less.The formation constants K_(1),K_(3)and K_(5)of B(OH)_(4)^(-),B_(3)O_(3)(OH)_(4)^(-)and B_(5)O_(6)(OH)_(4)^(-)were given by NMR experimental study.The reason for the low content of B_(5)O_(6)(OH)_(4)^(-)is that it depolymerizes into other borate ions.The addition of ions promoted the formation of pentaborate,while high temperature promoted the B_(5)O_(6)(OH)_(4)^(-)depolymerization.

关 键 词：物种分布图 核磁共振 五硼酸钾 硼酸根离子 

分 类 号：P645[天文地球—地质矿产勘探]