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41	Author	Tetramethylammoniumfluorid Bildung, Wasserstoffbrückenbindung Struktur, Dieter Stäben, Dietrich Mootz	Requires 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
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	TEI-XML for	default:Reihe_B/48/ZNB-1993-48b-1057.pdf
	Identifier	ZNB-1993-48b-1057
	Volume	48

42	Author	Michael Born, Dietrich Mootz, Sigrid Schaefgen	Requires 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
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	TEI-XML for	default:Reihe_B/50/ZNB-1995-50b-0101.pdf
	Identifier	ZNB-1995-50b-0101
	Volume	50

43	Author	Saalfrank, JochenN. Achtrab, Stephan Reck, Frank Hampel	Requires cookie*
	Title	Synthese und Aggregatbildung eines 5-Hydroxy-2,5-dihydropyrrols. Enantiomerenreine, eindimensionale Stränge durch Wasserstoff- brückenbindungen und chiroselektive Selbstorganisation [1]
	Abstract	Synthesis and A ggregation o f a 5-H ydroxy-2,5-dihydropyrrole. E nantiom erically Pure, O ne-dim ensional Strands via Hydrogen Bonds and Chiroselective S eif O rganization [ 1 ] R olf W. Reaction of dimethyl 1,3-acetonedicarboxylate 8 with oxalylchloride 2 and magnesium chlo ride as catalyst yielded 2,3-dioxo-2,3-dihydrofuran 9, which is in equilibrium with tautomer 10 (9:10 = 1:2). Addition of thionyl chloride to a mixture of 9/10 afforded 3-chloro-2(5H)-furanone 11. The structure of 11 was unequivocally established by X-ray diffraction, which indirectly pro ved the structure of 10 as well. Ring opening of 11 by nucleophilic attack with benzylamine 14 in C2-position and subsequent recyclization led to racemic 3-chloro-5-hydroxy-2-oxo-2,5-di-hydropyrrole 15. According to a single crystal X-ray analysis, 15 aggregates via stereospecific self selection through hydrogen bonds to give chiroselectively the one-dimensional strands 1 1(S)-15] and I [(R)-1SI
	Reference	Z. Naturforsch. 54b, 179—186 (1999); eingegangen am 28. September 1998
	Published	1999
	Keywords	2(5H)-Furanones, Hydrogen-Bonding, Chiral Recognition, One-Dimensional Strand, Crystal Structure
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	TEI-XML for	default:Reihe_B/54/ZNB-1999-54b-0179.pdf
	Identifier	ZNB-1999-54b-0179
	Volume	54

44	Author	Biing-Chiau Tzeng, Johann Zank, Annette Schier, Hubert Schmidbaur	Requires cookie*
	Title	The Structural Chemistry of GoId(I) Quinoline-2-thiolate and Iodide Complexes of Polytertiary Phosphines
	Abstract	Treatment of (chloro)gold(I) complexes of di-and tetra-tertiary phosphines with equivalent quantities of sodium quinoline-2-thiolate in methanol / dichloromethane affords the correspond ing (phosphine)gold(I) quinoline-2-thiolates in high yields. The di-and tetranuclear complexes, respectively, of a,u>bis(diphenylphosphino)-propane (1), -butane (2) and -pentane (3) and of tris(2-diphenylphosphino-ethyl)phosphine (4) have been obtained as crystalline solids, and the structures of 2 and 4 have been determined by single crystal X-ray diffraction studies. Un expectedly, the molecules of 2 are loosely aggregated into strings via weak intermolecular gold-sulfur, not via Au-Au interactions. Compound 4 is a monomeric tetranuclear cluster in the solid state with two intramolecular gold-gold bonds. Bis(2-diphenylphosphino-ethyl)-phenylphosphine (PPP) forms trinuclear complexes with gold(I) chloride, bromide and iodide (5a -c). The iodide complex features a chain structure through intermolecular Au -Au contacts between the two terminal P-Au-I units. The closest contacts between the chains are determined by Au-I and I -I interactions of the central P-Au-I unit.
	Reference	Z. Naturforsch. 54b, 825—831 (1999); received April 19 1999
	Published	1999
	Keywords	Gold(I) Complexes, Thiolate Complexes, Aurophilicity, Hydrogen Bonding, Polytertiary Phos-phine Complexes
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	TEI-XML for	default:Reihe_B/54/ZNB-1999-54b-0825.pdf
	Identifier	ZNB-1999-54b-0825
	Volume	54

45	Author	D. Blaschette, PeterG. Jones	Requires cookie*
	Title	Polysulfonylamine, CXVII [1]
	Abstract	Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Sechs systematisch variierte s££.-Ammonium-dimesylamide mit sechs verschiedenen null-, ein-oder zweidimensionalen Wasserstoffbrückenmustern Polysulfonylamines, C X V II [1] H ydrogen B onding in Crystalline O n iu m Dimesylamides: Six Systematically Varied sec. -A m m onium Dimesylamides Exhibiting Six D ifferent Zero-, One-, or Two-Dimensional Hydrogen B onding Patterns O liver Moers, Karna W ijaya, D agm ar Henschel, A rm a n In order to examine packing preferences and hydrogen bond patterns in secondary ammo nium salts, low-temperature X-ray analyses were conducted for six compounds of general formula R^N H ^M eSO ^hN ", where R 2NH2 = Me2NH2 (1, triclinic, space group P I),
	Reference	Z. Naturforsch. 54b, 1420—1430 (1999); eingegangen am 13. Juli 1999
	Published	1999
	Keywords	Di(methanesulfonyl)amide, Secondary Ammonium Cation, Crystal Structure, Hydrogen Bonding, Crystal Engineering
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	TEI-XML for	default:Reihe_B/54/ZNB-1999-54b-1420.pdf
	Identifier	ZNB-1999-54b-1420
	Volume	54

46	Author	Dagmar Henschel, Oliver Moers, Karna Wijaya, Blaschette Arm, PeterG. Jones	Requires cookie*
	Title	Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Drei prim. -Ammonium-dimesylamide mit zwei-oder dreidimensionalen Wasserstoffbrückenmustern Polysulfonylamines, CXVIII [1] Hydrogen Bonding in Crystalline Onium Dimesylamides: Three prim. -Ammonium Dimesylamides Exhibiting Two-or Three-Dimensional Hydrogen Bond Patterns
	Abstract	In order to study hydrogen bonding patterns in primary ammonium salts and the hydrogen bond acceptor potential of the dimesylamide anion, low-temperature X-ray structures have been determ ined for the 1:1 salts R N H ^M eSC ^^N -, where R = Et (1, monoclinic, space
	Reference	Z. Naturforsch. 54b, 1431—1440 (1999); eingegangen am 13. Juli 1999
	Published	1999
	Keywords	Di(methanesulfonyl)amide, Primary Ammonium Cation, Crystal Structure, Hydrogen Bonding, Ionic Self-Clathrate
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	TEI-XML for	default:Reihe_B/54/ZNB-1999-54b-1431.pdf
	Identifier	ZNB-1999-54b-1431
	Volume	54

47	Author	K. Am, Wijaya, Oliver Moers, A. Rm, Blaschette, PeterG. Jones	Requires cookie*
	Title	Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Ein antidromes Achtringmuster als robustes supramolekulares Synthon - Drei prototypische Strukturen Polysulfonylamines, CXIX [1, 2] Hydrogen Bonding in Crystalline Onium Dimesylamides: An Antidromic Eight-M embered Ring Pattern as a Robust Supramolecular Synthon - Three Prototypical Structures
	Abstract	Syntheses and low-temperature X-ray structures are reported for three ionic solids of gen eral formula BH +(M eS 0 2)2N_, where B H + is 3,4,6,7,8,9-hexahydro-2//-pyrimido[l,2-tf]pyri-midinium (1, monoclinic, space group P 2 1/c), N,N'-diphenylformamidinium (2, monoclinic, P2xlc), or 2-phenylaminopyridinium (3, triclinic, P I, two independent formula units). As a common feature, the onium cations in question exhibit a difunctional hydrogen-bond donor sequence H -N -C (s p 2) -N -H geometrically complementary to an O -S -N fragment of the anion. Consequently, the three crystal packings consist of discrete cation-anion pairs (for mula units) assembled by an N -H --N and an N -H ---0 hydrogen bond. In both independ ent ion pairs of 3, the N -H ---N bond originates from the pyridinium centre and the N-H-O bond from the amino group. The eight-membered ring [graph set N2 = R2(8), antidromic] that results in all these prototypical structures has potential as a new and robust supramolecular synthon. In each case, short C-H-O contacts with H -O < 260pm and C-H-O ^ 140° are present; in 2, two Car-H ---0 hydrogen bonds are assisted by a C(formyl)-H -O contact and a n -n interaction to create a centrosymmetric formula unit dimer.
	Reference	Z. Naturforsch. 54b, 1441—1449 (1999); eingegangen am 13. Juli 1999
	Published	1999
	Keywords	Di(methanesulfonyl)amide, Onium Cation, Crystal Structure, Hydrogen Bonding, Molecular Recognition, Supramolecular Synthon
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	TEI-XML for	default:Reihe_B/54/ZNB-1999-54b-1441.pdf
	Identifier	ZNB-1999-54b-1441
	Volume	54

48	Author	Wanda Wagner, Maria Zaborowska, Wlodzimierz Puzyna, David Shugar	Requires cookie*
	Title	Studies on Purine-Pyrimidine Hydrogen Bonded Base Pairing by Means of Absorption and Emission Spectroscopy
	Abstract	Procedures are described for measurement of association constants between potentially com plementary purine and pyrimidine bases by hydrogen bonding in non-aqueous medium by means of absorption and emission spectroscopy. The methods require that one of the two constituents be fluorescent and exhibit a long wavelength absorption band not, or only partially, overlapped by the second constituent. The foregoing has been applied to measurements of the association constants, and other parameters, of hydrogen-bonded complexes of 2-aminopurine with 1-substituted uracil, thymine and barbital in chloroform solution, both in the ground and excited states. It was estab lished that the 1:1 hydrogen-bonded base pairs 2-aminopurine : 1-cyclohexyluracil and 2-amino purine: 1-octylthymine maintain the ground-state equilibrium during the life time of the excited state, whereas for the corresponding pair 2-aminopurine: 1-methylbarbital this equilibrium is per turbed on excitation. The influence of N-alkylation of the 2-aminopurine residue on base-pairing with the pyrimidines has also been examined. The results are compared with those obtained by other methods. The specific advantages of the procedures employed, and their possible applications to studies on the behaviour of fluorescent residues in polynucleotides, are discussed.
	Reference	(Z. Naturforsch. 29c, 672 [1974]; received August 1 1974)
	Published	1974
	Keywords	Purines and Pyrimidines, Hydrogen Bonding, Base-pairing, Excited States, Fluorescence
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	TEI-XML for	default:Reihe_C/29/ZNC-1974-29c-0672.pdf
	Identifier	ZNC-1974-29c-0672
	Volume	29

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