B-11 and Na-23 solid-state NMR and density functional theory studies of electric field gradients at boron sites in ulexite

ISL OpenIR > 青海盐湖研究所知识仓储

	B-11 and Na-23 solid-state NMR and density functional theory studies of electric field gradients at boron sites in ulexite
	Zhou, Bing 1,2; Michaelis, Vladimir K.3; Kroeker, Scott 3; Wren, John E. C.3; Yao, Yefeng 4,5; Sherriff, Barbara L.6; Pan, Yuanming 7
	2013
发表期刊	CRYSTENGCOMM
卷号	15 期号:43 页码:8739-8747
摘要	Nuclear magnetic resonance (NMR) parameters of B-11 in borates and borosilicates, unlike those of many other nuclei such as Si-29 and Al-27, vary only over limited ranges and have been thought to be insensitive to local structural environments. High-resolution NMR spectroscopy at high (14 T) and ultrahigh (21 T) fields yield precise B-11 and Na-23 NMR parameters for ulexite, which contains the pentaborate polyanion ([B5O6(OH)(6)](3-)) as the fundamental building block (FBB). These NMR parameters are compared with ab initio theoretical calculations as implemented in WIEN2K, including optimization of the ulexite structure, determination of the electric field gradients (EFG) and consequently the nuclear quadrupole interaction (QI) parameters at the five distinct B sites, and calculations of the density of states (DOS). These calculations show that the magnitudes and signs of the EFG for B-[3] and B-[4] are determined by multiple factors, including the electron distributions in the B 2p(z) orbitals and their interactions with Ca-3p/O-2s orbitals. Most importantly, the calculated B 2p(z) orbitals at all B sites in ulexite are predominantly affected by the atoms within the fundamental building block, resulting in the insensitivity of the B-11 QI parameters to the weak interunit interactions among FBB. Calculations with the water molecules removed from the ulexite structure provide further support for the strong intraunit interactions in FBB as a cause for the poor sensitivity of B-11 NMR parameters to local structural environments, including hydrogen bonding, in borates.
语种	英语
引用统计
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/4439
专题	青海盐湖研究所知识仓储
作者单位	1.Tongji Univ, Coll Mat Sci & Engn, Shanghai 21000, Peoples R China 2.Chinese Acad Sci, Qinghai Inst Salt Lakes, Xining 810008, Peoples R China 3.Univ Manitoba, Dept Chem, Winnipeg, MB R3T 2N2, Canada 4.E China Normal Univ, Dept Phys, Shanghai 200062, Peoples R China 5.E China Normal Univ, Shanghai Key Lab Magnet Resonance, Shanghai 200062, Peoples R China 6.Univ Manitoba, Dept Geol Sci, Winnipeg, MB R3T 2N2, Canada 7.Univ Saskatchewan, Dept Geol Sci, Saskatoon, SK S7N 5E2, Canada
推荐引用方式 GB/T 7714	Zhou, Bing,Michaelis, Vladimir K.,Kroeker, Scott,et al. B-11 and Na-23 solid-state NMR and density functional theory studies of electric field gradients at boron sites in ulexite[J]. CRYSTENGCOMM,2013,15(43):8739-8747.
APA	Zhou, Bing.,Michaelis, Vladimir K..,Kroeker, Scott.,Wren, John E. C..,Yao, Yefeng.,...&Pan, Yuanming.(2013).B-11 and Na-23 solid-state NMR and density functional theory studies of electric field gradients at boron sites in ulexite.CRYSTENGCOMM,15(43),8739-8747.
MLA	Zhou, Bing,et al."B-11 and Na-23 solid-state NMR and density functional theory studies of electric field gradients at boron sites in ulexite".CRYSTENGCOMM 15.43(2013):8739-8747.