Go toArchive
Browse byFacets
Bookbag ( 0 )
'M elting Diagram' in keywords
Results  4 Items
Sorted by   
Section
Publication Year
1995 (1)
1993 (1)
1992 (1)
1984 (1)
1Author    Dietrich Mootz, Wolfgang PollRequires cookie*
 Title    Fluoride und Fluorosäuren, IX [1] Verbindungsbildung im System NOF—HF sowie Kristallstrukturen von N O F-3 HF und N O F -4 HF Fluorides and Fluoro Acids, IX [1] Com pound Form ation in the System N O F —H F and Crystal Structures of N O F -3 H F and N O F -4 H F  
 Abstract    The melting diagram o f the system N O F —H F (HF-rich region) was studied by D T A and X-ray diffraction. The com pounds N O F -3 H F and N O F -4 H F were confirmed as intermediate solid phases, and formation o f a new on e, N O F -7 H F , was observed. The m elting points are —1 °C (d e c .), 5 °C and —106 °C (d e c .), respectively. The crystal structures o f N O F -3 H F (space group 
  Reference    Z. Naturforsch. 39b, 1300—1305 (1984); eingegangen am 24. April 1984 
  Published    1984 
  Keywords    System N O F —H F, M elting Diagram, Crystal Structures, H ydrogen Bonding in Fluorides 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/39/ZNB-1984-39b-1300.pdf 
 Identifier    ZNB-1984-39b-1300 
 Volume    39 
2Author    Dietrich Mootz, Dieter StäbenRequires cookie*
 Title    Clathrathydrate von Tetramethylammoniumhydroxid: Neue Phasen und Kristallstrukturen [1] C lathrate Hydrates of Tetramethylammonium Hydroxide: New Phases and Crystal Structures [1]  
 Abstract    The melting diagram o f the system tetramethylammonium hydroxide-water has been re­ investigated in the region o f 6 6 .6 7 -100 mol% H 20 , using D T A , DSC and temperature-depend-ent X-ray powder diffraction. This was done as correction and supplementation o f a previous study in the same laboratory (D. M ootz, R. Seidel, J. Incl. Phenom. 8 , 139 (1990)). The system is now considered to contain as many as eight stable hydrates, three o f them dimorphic with a low-temperature a and a high-temperature ß form. The com positions are Me4N 0 H -x H 20 with x = 2 (a and ß), 4, 4.6 (a and ß), 5 (a and ß), 6.67, 7.5, 8.75 and 10. A second 7.5-hydrate, called 7 .5 a in the previous study, is now regarded as metastable. -Structure determinations have been performed for the new phases with x = 4.6 (a), 6.67 and 8.75. The 4.6a-hydrate, transforming to 4.6ß at 32 °C, is cubic with space group Pa 3 and Z = 40 formula units per unit cell. The lattice constant is a = 21.493Ä at -1 6 0 °C. The 6.67-hydrate, melting with decom ­ position at 13 °C, is monoclinic with space group P 2 ,/w and Z = 6 . It was studied as the O-deuterated isotype with unit-cell dimensions a -11.874, b = 20.019, c = 8.272 Ä and ß = 103.84° at 3 °C. The 8.75-hydrate, melting with decom position at -3 °C, is cubic with space group 143 d, Z = 16 and a -18.38(2) Ä at -2 0 °C. The three structures, as most others o f the higher hydrates o f the system studied previously, are those o f polyhedral clathrate hydrates. For the hydrates 4 .6 a and 6.67 deviations o f the anionic, i.e. proton-deficient, new water structures from being fully four-connected are described in detail. The 8.75-hydrate is isostruc-tural with the hitherto unparalleled 9.75-hydrate o f /-butyl amine. -The phase identity and structure o f the 4.6/?-hydrate were recognized as those attributed to an erroneously assumed 5/?-phase in the previous study. 5 ß now denotes the room-temperature form o f the penta-hydrate, previously called 5 a. The present 5 a is another o f the new phases and the only one o f the system with its structure still undetermined. 
  Reference    Z. Naturforsch. 47b, 263—2 (1992); eingegangen am 8. Juli 1991 
  Published    1992 
  Keywords    Clathrate Hydrates, Crystal Structures, Hydrogen Bonding, M elting Diagram, Tetramethylammonium Hydroxide 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/47/ZNB-1992-47b-0263.pdf 
 Identifier    ZNB-1992-47b-0263 
 Volume    47 
3Author    Tetramethylammoniumfluorid Bildung, Wasserstoffbrückenbindung Struktur, Dieter Stäben, Dietrich MootzRequires cookie*
 Title    Die kristallinen Hydrate  
 Abstract    The melting diagram of the system M e4N F -H 20 in the region 50-100 mol% H zO has been investigated for the first time, using D T A , D SC and tem perature-dependent X-ray powder diffraction. Four crystalline hydrates M e4N F\*H 20 were found, with x = 1 ,2 .3 3 ,4 and 5, which decom pose irreversibly above ca. 160 °C and m elt incongruently at 36 °C, congruently at 46 °C and again incongruently at 10 °C, respectively. The crystal structure o f each hydrate, except the already known one of the tetrahydrate, has b een determ ined with M oK a diffractom eter data. The monohydrate is rhombohedral with space group R3m and Z = 6 formula units per unit cell (hexagonal axes), the 2.33-hydrate m onoclinic with P2j/n and Z = 12, and the pen-tahydrate tetragonal with 142 m and Z = 2. The hydrogen-bonded H 20/F ~ structure is an iso­ lated centrosymmetric [F2(H 20) 2]2_ four-m em bered ring in the m onohydrate, a rather open three-dim ensional network in the 2.33-hydrate and a corrugated dense layer o f fused five-mem bered rings in the pentahydrate. 
  Reference    Z. Naturforsch. 48b, 1057—57 (1993); eingegangen am 5. April 1993 
  Published    1993 
  Keywords    Tetramethylamm onium Fluoride, Fluoride Hydrates, M elting Diagram, Crystal Structure, Hydrogen Bonding 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1057.pdf 
 Identifier    ZNB-1993-48b-1057 
 Volume    48 
4Author    Michael Born, Dietrich Mootz, Sigrid SchaefgenRequires cookie*
 Title    Tautomere Wasserschichten. Bildung und Struktur tiefschmelzender Trihydrate von Triethylamin und 4-Methylpyridin [1] Tautomeric Water Layers. Formation and Structure of Low-Melting Trihydrates of Triethylamine and 4-Methylpyridine [1]  
 Abstract    Low-melting trihydrates of triethylamine (E t3N) and 4-methylpyridine (4-M ePy) have been confirmed and detected by phase analysis and the crystal structures determined. Both are monoclinic with space group P 2!/c and Z = 4 formula units per unit cell. The lattice parameters are a = 13.606, b = 6.291, c = 12.412 A , and ß = 99.47° at -1 0 0 °C for Et3N -3 H 20 , and a = 9.982, b = 6.877, c = 12.958 Ä , and ß = 103.50° at -9 0 °C for 4-M eP y-3 H20 . The water m olecules in the two structures are hydrogen-bonded in condensed four-, five-, and six-membered rings with 1:2:1 ratio, thus forming characteristic layers parallel (1 0 0) of identical topology and tautomeric to each other. The amine m olecules are linked to both sides of the layers by O -H — N bonds from different O atoms. 
  Reference    (Z. Naturforsch. 50b, 101—105 [1995]; eingegangen am 11. August 1994) 
  Published    1995 
  Keywords    Am ine Hydrates, Crystal Structure, Hydrates, Hydrogen Bonding, M elting Diagram, Water Layers 
  Similar Items    Find
 DEBUG INFO      
 TEI-XML for    default:Reihe_B/50/ZNB-1995-50b-0101.pdf 
 Identifier    ZNB-1995-50b-0101 
 Volume    50