Coupled substitution of type A and B carbonate in sodium-bearing apatite
Coupled substitution of type A and B carbonate in sodium-bearing apatite
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DOI：
10.1016/j.biomaterials.2006.11.003
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发表时间：
2007-02-01
期刊：
影响因子：
14
通讯作者：
Liu, Xi
中科院分区：
文献类型：
--
作者：
Fleet, Michael E.;Liu, Xi
A- b型碳酸羟基磷灰石{Ca10-yNay[(PO4)(6-y)(CO3)(y)][(OH)(2-2x)(CO3)(x)]；在1200℃和0.5 ~ 1.0 gpa下合成了近似于y}的x，并用单晶x射线结构和FTIR光谱对其进行了研究。碳酸盐岩最大含量（11.1 wt%）的结晶数据为：a = 9.3855(7), c = 6.9142(4)埃，空间群P6(3)/m, R = 0.023, R-w = 0.014。取代的结构调节需要Na和通道（A型）和磷酸盐（B型）碳酸盐离子缺陷的局部耦合。B型碳酸盐离子位于取代磷酸基的斜面上，但与镜面呈53度角倾斜。FTIR光谱在1500 cm（-1）以上有最小的nu(3)吸收，在873 cm（-1）处有主要的v(2)吸收。因此，合成a-b型含钠磷灰石（a型碳酸盐含量高）在化学成分和红外光谱上与生物磷灰石相似。后者被重新解释为含钠型A-B型碳酸盐磷灰石，通道碳酸盐占总碳酸盐的50%。(c) 2006 Elsevier Ltd.版权所有。
A suite of Na-bearing type A-B carbonate hydroxyapatites {Ca10-yNay[(PO4)(6-y)(CO3)(y)][(OH)(2-2x)(CO3)(x)]; x approximate to y} has been synthesized at 1200 degrees C and 0.5-1.0GPa, and investigated by single-crystal X-ray structure and FTIR spectroscopy. Crystal data for the maximum content of carbonate (11.1 wt%) are a = 9.3855(7), c = 6.9142(4) angstrom, space group P6(3)/m, R = 0.023, R-w = 0.014. Structural accommodation of the substitutions requires local coupling of Na and channel (type A) and phosphate (type B) carbonate ion defects. The type B carbonate ion is located on the sloping faces of the substituted phosphate group, but is inclined at an angle of 53 degrees to the mirror plane. FTIR spectra have minimal nu(3) absorption beyond 1500 cm(-1) and dominant v(2) absorption at 873 cm(-1). Synthetic Na-bearing type A-B apatites (with a high content of type A carbonate) are thus similar in both chemical composition and infrared spectra to biological apatites. The latter are reinterpreted as Na-bearing type A-B carbonate apatites with channel carbonate up to 50% of total carbonate. (c) 2006 Elsevier Ltd. All rights reserved.