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|Section8= }} Iron(I) hydride is a chemical compound of iron and hydrogen with chemical formula FeH. It has been detected in isolation only in extreme environments, like trapped in frozen noble gases, in the atmosphere of cool stars, or as a gas at temperatures above the boiling point of iron. It is assumed to have three dangling valence bonds, and is therefore a free radical; its formula may be written FeH3• to emphasize this fact. At very low temperatures (below 10 K), FeH may form a complex with molecular hydrogen FeH·H2.〔 Iron(I) hydride is one of a few known compounds of iron and hydrogen, all equally rare; they also include iron dihydride (FeH2), stable only at very low temperatures, and a high-pressure iron-hydrogen alloy also with the formula FeH. Iron(I) hydride was first detected in the laboratory by B. Kleman and L. Åkerlind in the 1950s. == Occurrence in outer space == Iron hydride is one of the few molecules found in the Sun.〔 Lines for FeH in the blue-green part of the solar spectrum were reported in 1972, including many absorption lines in 1972.〔 Also sunspot umbras show up the Wing-Ford band prominently.〔 Bands for FeH (and other hydrides of transition metals and alkaline earths) show up prominently in the emission spectra for M dwarfs and L dwarfs, the hottest kind of brown dwarf. For cooler T dwarfs, the bands for FeH do not appear,〔 probably due to liquid iron clouds blocking the view of the atmosphere, and removing it from the gas phase of the atmosphere. For even cooler brown dwarfs (<1350 K), signals for FeH reappear, which is explained by the clouds having gaps.〔 The explanation for the kind of stars that the FeH Wing-Ford band appears in, is that the temperature is around 3000 K and pressure is sufficient to have a large number of FeH molecules formed. Once the temperature reaches 4000 K as in a K dwarf the line is weaker due to more of the molecules being dissociated. In M giant red giants the gas pressure is too low for FeH to form.〔 Elliptical and lenticular galaxies have also have an observable Wing-Ford band, due to a large amount of their light coming from M dwarfs.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Iron(I) hydride」の詳細全文を読む スポンサード リンク
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