Object: An object of the present invention is to provide a method for producing, with a high yield, a fluorinated organic compound, the fluorinated organic compound having not been produced with a sufficient yield by a conventional method for producing a fluorinated organic compound using a fluorinating agent containing IF.sub.5-pyridine-HF alone. Another object of the present invention is to provide a fluorinating reagent. Means for achieving the object: A method for producing a fluorinated organic compound comprising step A of fluorinating an organic compound by bringing the organic compound into contact with (1) IF.sub.5-pyridine-HF and (2) at least one additive selected from the group consisting of amine hydrogen fluorides, X.sup.aF (wherein X.sup.a represents hydrogen, potassium, sodium, or lithium), oxidizers, and reducing agents.

Object: An object of the present invention is to provide a method for producing, with a high yield, a fluorinated organic compound, the fluorinated organic compound having not been produced with a sufficient yield by a conventional method for producing a fluorinated organic compound using a fluorinating agent containing IF.sub.5-pyridine-HF alone. Another object of the present invention is to provide a fluorinating reagent. Means for achieving the object: A method for producing a fluorinated organic compound comprising step A of fluorinating an organic compound by bringing the organic compound into contact with (1) IF.sub.5-pyridine-HF and (2) at least one additive selected from the group consisting of amine hydrogen fluorides, X.sup.aF (wherein X.sup.a represents hydrogen, potassium, sodium, or lithium), oxidizers, and reducing agents.

Compositions and methods comprising one or more compounds according to Formula I:

##STR00001## where R.sub.1, R.sub.2 and R.sub.3 are each independently C.sub.xR′.sub.(2x+1)−yH.sub.y; each R′ is independently selected from F or Cl and wherein the value of (2x+1)−y is the total number of R′ substituents on the indicated carbon atom(s); each x is independently equal to or greater than 1 and equal to or less than 6; and y is equal to or greater than 0 and less than or equal to 2x+1, provided that the total number of R′ present in the compound is 6 or greater, and that the compound has from zero up to two (2) Cl substituents.

To provide a fluorinated ether compound capable of forming a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance and light resistance; a fluorinated ether composition and a coating liquid containing the fluorinated ether compound; an article having a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance and light resistance and a method for producing it. A fluorinated ether compound having a poly(oxyperfluoroalkylene) chain having a unit (a) which is an oxyperfluoroalkylene unit having 5 or 6 carbon atoms, and a unit (P) which is an oxyperfluoroalkylene unit having at most 4 carbon atoms, and having at least one of a hydrolysable silyl group and a silanol group on at least one terminal of the poly(oxyperfluoroalkylene) chain via a linking group.

The present disclosure provides a method for producing a composition comprising a purified fluorine-containing ether compound represented by formula (1): CHX.sup.1X.sup.2CF.sub.2OX.sup.3, wherein X.sup.1 and X.sup.2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X.sup.3 represents a C.sub.1-6 alkyl group, provided that not both X.sup.1 and X.sup.2 are trifluoromethyl groups.

The present disclosure provides a method for producing a composition comprising a purified fluorine-containing ether compound represented by formula (1): CHX.sup.1X.sup.2CF.sub.2OX.sup.3, wherein X.sup.1 and X.sup.2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X.sup.3 represents a C.sub.1-6 alkyl group, provided that not both X.sup.1 and X.sup.2 are trifluoromethyl groups.

Provided is a novel production method for a fluorinated organic compound (1), the method comprising step A of fluorinating a hydrogen atom-containing organic compound (2) using IF.sub.5 in a liquid composition comprising an organic solvent, the amount of the hydrogen atom-containing organic compound (2) being 1.8 mol or more per liter of the organic solvent.

Provided is a novel production method for a fluorinated organic compound (1), the method comprising step A of fluorinating a hydrogen atom-containing organic compound (2) using IF.sub.5 in a liquid composition comprising an organic solvent, the amount of the hydrogen atom-containing organic compound (2) being 1.8 mol or more per liter of the organic solvent.

Ethoxy-nonafluorobutane (C.sub.4F.sub.9OC.sub.2H.sub.5) is used as an immersion medium for immersing an immersion objective of a cryo-light microscope. The cryo-light microscope comprising an immersion objective, a front lens mount holding a front lens of the immersion objective, a sample holder and a cold stage carrying the sample holder further has a heating device coupling a heat flow into the front lens mount.

Ethoxy-nonafluorobutane (C.sub.4F.sub.9OC.sub.2H.sub.5) is used as an immersion medium for immersing an immersion objective of a cryo-light microscope. The cryo-light microscope comprising an immersion objective, a front lens mount holding a front lens of the immersion objective, a sample holder and a cold stage carrying the sample holder further has a heating device coupling a heat flow into the front lens mount.