Fine structure in the infrared OH-stretching bands of holmquistite and anthophyllite
Fine structure in the infrared OH-stretching bands of holmquistite and anthophyllite
复制标题
赤镁石和直闪石红外 OH 伸缩带的精细结构
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
F. Hawthorne
中科院分区：
文献类型：
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作者：
K. Ishida;F. Hawthorne
斜方晶系（Mg，Fe，Mn，Li）角闪石、斜方闪石和直闪石中的主要红外OH伸缩带显示出精细结构，这是由于晶体结构中存在两个对称的OH基团。在斜方角闪石结构中存在两种不同的四面体双链，即A链和B链。B链比A链旋转更多，并且每个OH位点周围的立体化学表明与B链的桥接阴离子的氢键比与A链的桥接阴离子的氢键更强。这种差异足以将OH 2伸缩主带的频率移动到较低的频率，并允许在红外光谱中分辨这两个带。这种区别可以允许检测可能的OH，F之间的两个不同的单价阴离子网站的斜方闪石结构的顺序。
AbstractThe principal infrared OH-stretching bands in the orthorhombic (Mg, Fe, Mn, Li) amphiboles holmquistite and anthophyllite show fine structure due to the occurrence of two symmetrically distinct OH groups in the crystal structure. There are two distinct tetrahedral double chains in the orthorhombic amphibole structure, the A chain and the B chain. The B chain is more rotated than the A chain, and the stereochemistry around each of the OH sites suggests that the hydrogen bond to the bridging anion(s) of the B chain is stronger than the hydrogen bond to the bridging anion(s) of the A chain. This difference is sufficient to shift the frequency of the principal OH2-stretching band(s) ∼5 cm−1 to lower frequency, and allows resolution of the two bands in the infrared spectrum. This distinction could allow detection of possible OH, F ordering between the two distinct monovalent-anion sites in the orthorhombic amphibole structure.