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1Author    Akinobu Sasane, Hisanori Shinohara, Yoshihiro Mori, Yoshio Kume, Tetsuo Asaji, Daiyu NakamuraRequires cookie*
 Title    A Temperature Dependence Study of 35 C1 Nuclear Quadrupole Resonance Frequencies in Some Hexachloroplatinate(IV) Hexahydrates  
 Abstract    The temperature dependence of 35 C1 NQR frequencies was investigated in various hexachloro-platinate(IV) hexahydrates containing the following divalent ions as counter cations: Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Ba(II). All of the compounds except the Cu(II) and Ba(II) salts yield a single 35 C1 NQR line at all temperatures studied. For the Mn(II), Cu(II), and Ba(II) salts, the NQR frequencies are considerably shifted by deuteration. For the deuterated Mn(II) salt, two 35 C1 NQR lines were observed whose relative peak-height intensities vary in dependence on the history of the thermal treatment of the sample. The very broad higher frequency line could be observed for a sample which had been at 77 K or below. It could not be observed for a sample which was cooled slowly to room temperature after it had been heated up to ca. 420 K. A structural phase transition was located at 135. 6 and 129. 4 K for the Cu(II) salt and its deuterated analog, respectively. The frequency shift by deuteration is discussed in relation to the strength of O-H ... CI type hydrogen bonds. 
  Reference    Z. Naturforsch. 42a, 611—616 (1987); received February 171987 
  Published    1987 
  Keywords    Magnetic resonance (NQR), hydrogen bonding, phase transition 
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 TEI-XML for    default:Reihe_A/42/ZNA-1987-42a-0611.pdf 
 Identifier    ZNA-1987-42a-0611 
 Volume    42 
2Author    Haruo Niki, Ryokan Igei, Takuya Higa, Masao Hashimoto, Takahiro IsonoRequires cookie*
 Title    Lattice Imperfections and Relaxation of Cl NQR in Chloral Iso-Butylhemiacetal  
 Abstract    The temperature dependence of the S/N ratios of three 35 C1 NQR lines (v l5 v 2 , v 3) in chloral iso-butylhemiacetal shows interesting features in the range 77-300 K. 35 C1 T y indicates that above 220 K reorientation of CC1 3 is excited, and this results in a gradual decrease in S/N. The activation energy calculated from 35 C1 NQR T l results is 30 kJ mol -1 for v x and v 2 but 25 kJ mol -1 for v 3 . The difference seems to be attributable to the motion of H in the OH group. A minimum of 35 C1 NQR T 2 is found around 180 K but 35 C1 T\ shows no anomaly. 35 C1 T 2 determines the S/N ratios in the range between 130-220 K. The line broadening below 130 K is attributable to an inhomo-geneity of the electric field gradient at resonant nuclei produced by lattice defects. 
  Reference    Z. Naturforsch. 45a, 481—484 (1990); received August 26 1989 
  Published    1990 
  Keywords    NQR, Lattice imperfections, Magnetic relaxation, Hydrogen bonding 
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 TEI-XML for    default:Reihe_A/45/ZNA-1990-45a-0481.pdf 
 Identifier    ZNA-1990-45a-0481 
 Volume    45 
3Author    M. Wichmann, M. StockhausenRequires cookie*
 Title      
 Abstract    Relaxation spectra have been measured at 20°C for mono-, di-and triethanolamine in the pure liquid state and in a 0.6 mole fraction mixture with 1,4-dioxane. The general resemblance to the dielectric behaviour of alcohols and aminoalcohols shows that relaxation is governed by association effects. In this regard, several features point to significantly differing behaviour of the mono compound in comparison with both di-and triethanol­ amine. 
  Reference    Z. Naturforsch. 56a, 603—604 (2001); received June 18 2001 
  Published    2001 
  Keywords    Association, Dielectric Spectroscopy, Hydrogen Bonding, Liquids 
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 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0603_n.pdf 
 Identifier    ZNA-2001-56a-0603_n 
 Volume    56 
4Author    Beatrix Milewski-Mahrla, Hubert SchmidbaurRequires cookie*
 Title    Synthese und Kristallstrukturen einiger Tetramethylstibonium-Hydrogendicarboxylate Synthesis and Crystal Structures of Some Tetramethylstibonium Hydrogendicarboxylates  
 Abstract    Reactions of pentamethylantimony (CH^sSb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramethylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed. The crystal structures of the hydrogen-dibenzoate (1), hydrogen-ortho-phthalate (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter-actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH^Sb-tetrahedron in 1 is distorted by two benzoate oxygen atoms (at 304(2) and 340(2) pm). The cation in 2 is largely undistorted and the anion has a bydrogenpbthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate. 
  Reference    Z. Naturforsch. 37b, 1393—1401 (1982); eingegangen am 5. Juli 1982 
  Published    1982 
  Keywords    Pentamethylantimony, Tetramethylstibonium Salts, Hydrogendicarboxylates, Hydrogen Bonding, X-ray 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-1393.pdf 
 Identifier    ZNB-1982-37b-1393 
 Volume    37 
5Author    KurtH. Pilgram, LairdH. Gale, GlennE. PollardRequires cookie*
 Title    a-hydroxyphostones  
 Abstract    The addition-cyclocondensation reactions of three /?-hydroxyketones with four dialkyl phosphites gave 2-alkoxy-3-hydroxy-l,2-oxaphospholane-2-oxides ("a-hydroxyphosto-nes") (7), in moderate yields. In the solid state and in solution, these compounds exist as dimers with hydrogen bonding between the hydroxyl group and the phosphoryl oxygen atom of an adjacent molecule. The crystal and molecular structure of 3-hydroxy-2-methoxy-3,5,5-trimethyl-l,2-oxaphospholane-2-oxide (7 a) has been determined by single-crystal X-ray crystallography: C7H15O4P, monoclinic space group P2-l/n, cell dimensions a = 8.087(1) Ä, b = 13.386(2) A, c = 9.306(1) A, V = 1007.4 Ä 3 , Z = 4, final R = 0.052. The five-membered ring is puckered, with the carbon bearing the OH and CH3 groups lying out of the plane of the remaining four atoms in the ring. The doubly bonded oxygen attached to the phosphorus atom and the hydroxyl oxygen are in a cis-relationship. The 0(l)-0(4) intermolecular bond distance of 2.75 Ä suggests hydrogen bonding. The 0(1)-H(1) intermolecular bond distance of 1.97 Ä is consistent with this conclusion. Thorough synthetic studies have been carried out on intramolecular esters of 3-hydroxyalkane (and alkene) phosphonic and phosphinic acids (phosto-nes [1]). For example, dehydration of 3-hydroxy-alkanephosphonic acids gave phostones of general structure 1 [2] (Table I). Similar phostones, 2 and 3, were obtained from the reactions of 1,3-dihalo-alkanes with phosphonites and phosphinites, re-spectively [3]. At elevated temperature, 3-bromo-alkanephosphonates are converted into phostones 4 [4]. Acyl-lactone rearrangement of a-acetyl-a-diethoxyphosphonylbutyrolactone gave 5 [5]. Unsaturated phostones (8) are obtained by dehydration of the corresponding (3-hydroxy-3-phenyl-prop-2-enyl)phosphonic acids [6]. 3-Hy-droxypropenylphosphonates, prepared by catalytic reduction of 3-hydroxy-l-propynyl-phosphonates, cyclocondense to 9 having potent Cholinesterase inhibitory activity [7]. The reaction of dialkyl 1,2-alkadienylphosphonates with halogens [8-10] and sulfenyl chlorides [12] gave 10. In the reaction of 3-methyl-l,2-butadienephos-phonyl di chloride with halogens, unsaturated tetra-halophostones (11), are formed [13]. The chlorina-tion of 2-methyl-2,3,5-hexatriene-4-phosphonyl di-chloride proceeds similarly in the direction of cyclo-dechlorination to form 12 [14]. 
  Reference    Z. Naturforsch. 38b, 1122—1129 (1983); received May 6 1983 
  Published    1983 
  Keywords    X-Ray, Stereochemistry, Hydrogen Bonding, Dimerization 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1122.pdf 
 Identifier    ZNB-1983-38b-1122 
 Volume    38 
6Author    Dietrich Mootz, Wolfgang PollRequires cookie*
 Title    Fluoride und Fluorosäuren, VI Verbindungsbildung und Kristallstrukturen im System Ammoniak—Fluorwasserstoff [ 1 , 2 ] Fluorides and Fluoro Acids, VI Com pound Form ation and Crystal Structures in the System A m m onia-H ydrogen Fluoride  
 Abstract    The melting diagram of the quasi-binary system NH3— HF between the limits NH4HF: and HF was redetermined. The compounds NH 3 • 4H F. NH3 • 5HF and NH3 ■ 8HF with melting points of 26. —14 (dec.) and —95 °C (dec.), respectively, were established as the stable phases. Their crystal structures were determined as those of ammonium hydrogen fluorides NH4[F(HF)3], NH4[F(HF)4] and NH4[HF:(H F)3] • 3HF with extended N -H --F and F -H -F hydrogen bonding. 
  Reference    Z. Naturforsch. 39b, 290—297 (1984); eingegangen am 15. September 1983 
  Published    1984 
  Keywords    System NH3 — HF, Melting Diagram Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/39/ZNB-1984-39b-0290.pdf 
 Identifier    ZNB-1984-39b-0290 
 Volume    39 
7Author    Christian RoblRequires cookie*
 Title    Erdalkaliquadratate, VI [1] SrC 4 0 4 -3H 2 0, Typ III Alkaline-earth Squarates, VI [1] SrC 4 0 4 -3H 2 0, Type III  
 Abstract    SrC 4 0 4 -3H 2 0, type III, was obtained in an aqueous silica gel besides crystals of SrC 4 0 4 • 3 H 2 0, type I. X-ray crystal structure analysis showed close relationship to BaC 4 0 4 -3H 2 0, but no iso-typism. Sr 2+ is coordinated by four water molecules and four oxygen atoms of the squarate dianion. The connection of Sr 2+ with C 4 0 4 2 leads to layers. The geometry of C 4 0 4 2 is typical for delocalized jr-systems. The O squarate atoms are not equally bound to Sr 2+ . One O squarate atom (0(4)) is bound to two Sr 2+ , two (O(l), 0(2)) are bound to one Sr 2+ , respectively, and the fourth O squaraIe atom (0(3)) shows no bonding contact to Sr 2+ . These differences are compensated for by inter-molecular hydrogen bonds which involve 0(3) three times, O(l) and 0(2) once each, but not 0(4). 
  Reference    (Z. Naturforsch. 43b, 99—103 [1988]; eingegangen am 21. September 1987) 
  Published    1988 
  Keywords    Strontium Squarate Type III, Preparation, Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-0099.pdf 
 Identifier    ZNB-1988-43b-0099 
 Volume    43 
8Author    Christian RoblRequires cookie*
 Title    Komplexe mit aromatischen Carbonsäuren, IV [1] Ca 2 [C 6 H 2 (COO) 4 ] * 6 H 2 0 -Eine neue Schichtstruktur Complexes with Aromatic Carboxylic Acids, IV [1] Ca 2 [C 6 H 2 (C00) 4 ]-6H 2 0 -A Novel Layer Structure  
 Abstract    Single crystals of Ca 2 [C 6 H 2 (COO) 4 ]-6H 2 0 were grown in aqueous silica gel. Ca :+ hasCN 6+2. The coordination polyhedron is formed by three water molecules and five oxygen atoms of carboxylate groups. Six oxygen atoms are closely bound (235,9—243,9 pm), the two remaining coordination partners are considerably more remote from Ca 2+ (268,2 and 273,8 pm). COO" groups chelate Ca :+ in an asymmetric manner, but the C —O bond lengths do not differ markedly (125,2—126,3 pm). The connection of Ca 2+ with [C,H 2 (COO) 4 ] 4_ leads to rigid layers. Adjacent layers are interlinked by hydrogen bonds. Those oxygen atoms which are weakly bound to Ca 2+ are favoured as proton acceptors in hydrogen bonds. The COO groups are tilted differently against the C 6 -ring plane. One is approximately coplanar, but the other is oriented almost perpen-dicularly. 
  Reference    Z. Naturforsch. 43b, 993—997 (1988); eingegangen am 11. April 1988 
  Published    1988 
  Keywords    Pyromellitate, Layer Structure, Preparation, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-0993.pdf 
 Identifier    ZNB-1988-43b-0993 
 Volume    43 
9Author    Crystal, FrankH. Artm Anna, D. Ietrich, M. Ootz, Reinhard SchwesingerRequires cookie*
 Title    Zur Kristallchemie ungeladener Phosphazen-Basen, I [1] Strukturen zweier Hydrate und eines Acetats von Tris(dimethylamino)methyliminophosphoran  
 Abstract    C hem istry o f U ncharged Phosphazene Bases, I [ 1 ] Structures o f Two H ydrates and an A cetate o f T ris(dim ethylam ino)m ethylim inophosphorane Two hydrates and an acetate of the uncharged, very strong phosphazene base tris(dimethylamino)methyliminophosphorane, (Me2N)3P=NMe (for short Me-P]), have been characterized by their crystal structures. A monohydrate, Me-P, • H:0 , mp. 3°C, is monoclinic 
  Reference    Z. Naturforsch. 51b, 1369—1374 (1996); eingegangen am 11. März 1996 
  Published    1996 
  Keywords    Crystal Structure, Hydrate, Hydrogen Bonding, Phosphazene, Uncharged Base 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-1369.pdf 
 Identifier    ZNB-1996-51b-1369 
 Volume    51 
10Author    Cl Walter, Frank, GuidoJ. ReißRequires cookie*
 Title    Spezielle Alkylammoniumhexachlorometallate, II [1] Synthese und Kristallstruktur von Bis(l,2-diammoniopropan)hexachlororhodat(III)-chlorid, [H3N-CH(CH3)-CH2-NH3]2[RhCl6]Cl Alkylammonium Hexachlorometallates, II [1] Synthesis, and Crystal Structure of Bis( 1,2-diammoniopropane) Hexachlororhodate(III) Chloride, (H3N-CH(CH3)-CH9-NH3]-,|RhCl6]  
 Abstract    Bis(1,2-diammoniopropane) hexachlororhodate(III) chloride, [H ^N -CH tCI-fO -CH i-N H ^ [RhCl6]Cl (1) has been obtained by the reaction of rhodium(III) chloride with rac-1,2-diammoniopropane dihydrochloride in hydrochloric acid solution. The quasi-ternary com ­ pound, which crystallizes in the orthorhombic space group Pbca (a -11.0007(13) A, b = 22.181(2) A, c = 14.638(2) A, V = 3571.7(7) Ä \ T = -1 2 0 °C, Z -8) contains two crystallographically independent 1,2-diammoniopropane ions beside one hexachlororhodate and one chloride ion. One of the cations shows a R/S-S/R-disorder of enantiomeric pairs in the centrosymmetric crystal lattice. The packing scheme is determined by a complex framework of hydrogen bonds. 
  Reference    Z. Naturforsch. 51b, 1459—1463 (1996); eingegangen am 9. April 1996 
  Published    1996 
  Keywords    Hexachlororhodate, Alkylammonium Salt, Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-1459.pdf 
 Identifier    ZNB-1996-51b-1459 
 Volume    51 
11Author    Walter Frank, GuidoJ. ReißRequires cookie*
 Title    Spezielle Alkylammoniumhexachlorometallate, III [1] Synthese und Kristallstruktur von Tris(guanidinium)- hexachlororhodat(III)-monohydrat, [C(NH2)3 ]3 [RhCl6] * H20 Alkylammonium Hexachlorometallates, III [1] Synthesis, and Crystal Structure of Tris(guanidinium) Hexachlororhodate(III) Monohydrate, [C(NH2)3]3[RhCl6] * H20  
 Abstract    Tris(guanidinium) hexachlororhodate(III) monohydrate, [C(NH2)3]3[RhCl6] • H20 (1) has be­ en obtained by the reaction of rhodium(III) chloride with guanidine hydrochloride in hydrochlo­ ric acid solution. 1 crystallizes in the triclinic space group P i (o = 7.6013(9) A, b = 8.6912(10) A, c = 15.956(2) Ä, q = 93.177(10)°, ß = 101.691(10)°, 7 = 113.995(9)°, V = 931.8(2), Z = 2). Two crystallographically independent hexachlororhodate ions, three crystallographically independent guanidinium ions and one water molecule are linked by a complex framework of hydrogen bonds. 
  Reference    Z. Naturforsch. 51b, 1464—1468 (1996); eingegangen am 9. April 1996 
  Published    1996 
  Keywords    Hexachlororhodate, Guanidinium Salt, Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-1464.pdf 
 Identifier    ZNB-1996-51b-1464 
 Volume    51 
12Author    Stefan Horstmann, Wolfgang SchnickRequires cookie*
 Title    Synthese, Kristallstruktur und Eigenschaften von 1,1,3,3,3-Pentaamino- l-th io -l A \3 A 5-diphosphaz-2-en (NH2)2P(S)N=P(NH2)3 Synthesis, Crystal Structure, and Properties of 1,1,3,3,3-Pentaam ino-l-thio-l A5,3A5-diphosphaz-2-ene (N H 2)2P(S)N =P(NH 2)3  
 Abstract    (NH2)2P(S)N=P(NH2)3 has been prepared by a two step synthesis. Suitable single crystals were obtained from an acetonitrile solution in a temperature gradient between 60 °C and room temperature. The crystal structure of (NH->)tP(S)N=P(NH->)3 has been determined by single cry­ stal X-ray methods (P2,/c, a = 9 9 8 .2 7 (9)> '= 762.78(8), c = 1007.70(15) pm, ß = 107.340(7)°, Z = 4). In the crystal structure each hydrogen atom is subject to a hydrogen bond. Four N-H -N hydrogen bonding interactions per molecule build up a framework connecting two molecules in eight-membered rings. Each sulfur atom shows six distances N -H -S in the range of weak hydrogen bonding interactions. 
  Reference    Z. Naturforsch. 52b, 490—95 (1997); eingegangen am 18. Dezember 1996 
  Published    1997 
  Keywords    Aminophosphazenes, Synthesis, Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-0490.pdf 
 Identifier    ZNB-1997-52b-0490 
 Volume    52 
13Author    Frank Wendland, Christian Näther, Michael Schur, Wolfgang BenschRequires cookie*
 Title    Solvothermal Synthesis and Crystal Structure Determination of Tris- (ethyleneamine-ammonium) Tetraselenoantimonat: Non-Centrosymmetry Mediated by an Extended Unusual N-H***N Hydrogen Bonded Network?  
 Abstract    The title compound has been synthesized under solvothermal conditions by the reaction of elemental chromium, antimony and selenium in a solution of 40% 1,2-ethanediamine (en) in methanol. The crystal structure consists of tetrahedral SbSe,*3 --anions which are connected by monoprotonated 1,2-ethanediamine (enH+) cations via N-H--Se hydrogen bonding. The enH+ cations are joined via strong N-H -N hydrogen bonds between the ammonium hydrogen and the amino nitrogen atom forming four distinct chains, each built up of three crystallographically independent enH+ cations. Two of these chains are running parallel to [100], the other two are parallel to [010]. Based on this arrangement different centrosymmetric or non-centrosymmetric hydrogen bonding patterns are possible, but only in one chain the sequence of NH2 and NH3+ groups was determined by X-ray diffraction. 
  Reference    Z. Naturforsch. 53b, 1144—1148 (1998); received June 15 1998 
  Published    1998 
  Keywords    Selenoantimonates, Solvothermal Synthesis, Crystal Structure, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/53/ZNB-1998-53b-1144.pdf 
 Identifier    ZNB-1998-53b-1144 
 Volume    53 
14Author    Z. NaturforschRequires cookie*
 Title    Hydrogen Bonding of two l-(0-Ammonioalkyl)-2-acyl-cyclopentadienides in the Solid State  
 Abstract    A n d re a s M ü ller a n d G e rh a rd M aas The solid-state structures of a l-(0-ammoniopropyl)-2-(2-thienylcarbonyl)-cyclopenta-dienide (2) and a l-(0-ammoniopentyl)-2-(4-methoxybenzoyl)-cyclopentadienide (3) have been determined. Both betaines self-assemble by NH — O hydrogen bonds, but the motifs are different. In the ammoniopropyl case, both intramolecular and intermolecular hydrogen bonds of this type exist, the latter bond being responsible for the formation of infinite chains. In the ammoniopentyl case, intermolecular hydrogen bonds build up a two-dimensional net­ work which contains centrosymmetric dimers held together by NH • • • 0=C-aryl hydrogen bonds. 
  Reference    Z. Naturforsch. 55b, 541—545 (2000); received April 13 2000 
  Published    2000 
  Keywords    Cyclopentadienides, Hydrogen Bonding, Zw itter Ions 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0541.pdf 
 Identifier    ZNB-2000-55b-0541 
 Volume    55 
15Author    Cungen Zhang, Christoph Janiak, Horst BrombacherRequires cookie*
 Title    Structural Influence of Hydrogen Bonding and ^r-Stacking in fra/is-Diazido-tetra- kis(pyrazole)nickel(II) and rra/is-Diazido-tetrakis(3-methylpyrazoIe)nickel(II)  
 Abstract    The molecular nickel complexes fra«s-diazido-tetrakis(pyrazole)nickel(II) and trans-dia-zido-tetrakis(3-methylpyrazole)nickel(II) feature terminal monohapto-bound azide ligands. The pyrazole (pyr) ring planes are aligned along the Nazide-Ni-Nazide axis by intramolecular N-H—Nazide bonds. The crystal packing is controlled by jr-stacking between both pyrazole rings and azide ligands, N -H —Nazide hydrogen bonds, and intermolecular N-H—jrpyr and C-H —N/jrazide interactions. 
  Reference    Z. Naturforsch. 56b, 1205—1208 (2001); received July 20 2001 
  Published    2001 
  Keywords    Nickel Complexes, ^-Stacking, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-1205.pdf 
 Identifier    ZNB-2001-56b-1205 
 Volume    56 
16Author    Swathi Pisupati, P. A. Kumar, V.G K M PisipatiRequires cookie*
 Title    Induced Smectic-G Phase through Intermolecular Hydrogen Bonding Part IX: Comparative Thermal and Phase Behaviour Studies on Two Distinct Structural Isomers Possessing Linear and Bow Shapes  
 Abstract    Two novel intermolecular hydrogen bonding mesogenic series comprising two distinct structural iso­ mers nABA:R:nABA and «ABA:H:«ABA (where R = resorcinol; H = hydroquinone; nABA = p-n-al-kyloxybenzoic acid with the alkyl carbon number varying from propyl-to decyl-and dodecyl-) have been synthesized using resorcinol and hydroquinone as central bent and linear cores, respectively. The thermal and phase behaviour of these complexes is studied by thermal microscopy and differential scan­ ning calorimetry. The IR spectral data confirm the formation of intermolecular hydrogen bonding between the OH group of the non-mesogen and -COOH group of the nABA moiety. Thermal studies reveal the existence of new phases: smectic-A and smectic-G. Comparative phase transition studies sug­ gest that these isomers exhibit a different trend of mesomorphism. 
  Reference    Z. Naturforsch. 56a, 692—696 (2001); received July 4 2001 
  Published    2001 
  Keywords    Hydrogen Bonding, Thermal, Phase Behaviour, rtABA:R:rcABA, nABA:H:rcABA 
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 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0692.pdf 
 Identifier    ZNA-2001-56a-0692 
 Volume    56 
17Author    A.N G ArgRequires cookie*
 Title    Correlation of Mössbauer Quadrupole Splitting ( zI/?q) and Infrared Cyanide Frequency Separation in Alkali Metal Ferricyanides  
 Abstract    Mössbauer and infrared spectra of the alkali metal ferricyanides M* [Fe(CN)6] • n H 20 , where M1 = H , Li and N a were studied at room temperature. All the three compounds displayed a doublet with small quadrupole splitting (AEq). Infrared spectra of these compounds in solid state gave two frequencies for C = N stretching vibrations with their separation (Av) in increasing order which was found to be linearly correlated with AEq. A plausible explanation has been given in terms of the interaction of Li+ and Na+ cations w ith the CN-ligands of octahedrally symmetric ferricyanide anion [Fe(CN)6] 3-similar to that of hydrogen atoms which are hydrogen bonded in H 3Fe(CN)6. 
  Reference    (Z. Naturforsch. 30b, 96—98 [1975]; received February 1 /September 3 1974) 
  Published    1975 
  Keywords    Mössbauer Effect, IR Spectra, Ferricyanide Complexes, Hydrogen Bonding, Molecular Structure 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0096.pdf 
 Identifier    ZNB-1975-30b-0096 
 Volume    30 
18Author    1h NmRequires cookie*
 Title    H-NM R-und IR-spektroskopische Untersuchungen zur Konformation von Hydroxy - methyl-Substituenten in 2.3-Stellung an Hexachlorbicycloheptenen  
 Abstract    -an d IR -S pectroscopic C onform ational Studies on H ydro x y m eth y l S u b stitu en ts in th e 2,3 P ositions of H exachlorobicycloheptenes H e l l m u t S i n g e r *, I n g o l f S c h u p h a n ** u n d K a r l h e i n z B a l l s c h m i t e r Mono Hexachloro-bicycloheptenes and heptadienes with hydroxym ethyl-substituents in the 2 and 3 position show non-equivalence of the methylene protons in their NMR spectra. This is caused both by hindered rotation and the asymmetry of the molecules. For some molecules the spectroscopic data allow conclusions to be made concerning the con­ formation of the substituents. 
  Reference    (Z. Naturforsch. 30b, 373—377 [1975]; eingegangen am 9. Dezember 1974) 
  Published    1975 
  Keywords    -hydroxymethyl-bicycloheptenes, Bis-hydroxymethyl-bicycloheptenes, Heptadienes, Hindered Rotation, Hydrogen Bonding 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0373.pdf 
 Identifier    ZNB-1975-30b-0373 
 Volume    30 
19Author    Ger Vos, AnthonieJ. De Kok, GerritC. VerschoorRequires cookie*
 Title    Complexes of 1,2,4-Triazoles, Part XVII The Crystal Structure of Tris-/«-(4-ethyl-l,2,4-triazole-N l ,N 2 )- (4-ethyl-l,2,4-triazole-N 1 )-aquo-bis [bis(thiocyanato-N)- nickel(II)]hydrate, Ni2(C4N3H7)4(H20)(NCS)4 *H20 (x ~ 2.5)  
 Abstract    The crystal structure of Ni2(C4N3H7)4(H20)(NCS)4 • 2.5 H20 has been determined by X-ray diffraction techniques. The compound crystallizes in the monoclinic space group P2i/n with a — 15.121(4), 6= 13.237(2), c= 18.069(3), ß = 94.71(2)° and Z = 4; R = 0.040 (Rm = 0.051). The compound consists of dimeric units in which two Ni ions are bridged by three ethyltriazole (Ettrz) groups. For one Ni, two N donating NCS" groups and an Ettrz coordinating by only one N atom complete the NiNe octahedron. The other Ni atom, which is also octahedrally coordinated, has a coordinated water molecule instead of a monodentate Ettrz. 
  Reference    Z. Naturforsch. 36b, 809—813 (1981); received April 2 1981 
  Published    1981 
  Keywords    4-Ethyl-l, 2, 4-triazole, Binuclear Compound, Hydrogen Bonding 
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 Identifier    ZNB-1981-36b-0809 
 Volume    36 
20Author    Dietrich Mootz, D. Agm Ar BoenigkRequires cookie*
 Title    Fluoride und Fluorosäuren, VII [1] Kristallstrukturen von Säurehydraten und Oxoniumsalzen, XXII [2] Hydratbildung der Trifluoressigsäure sowie Strukturen eines Monohydrats und eines Tetrahydrats [3] Fluorides and Fluoro Acids, VII [1] Crystal Structures of Acid H ydrates and Oxonium Salts, XXII [2] H ydrate Form ation of Trifluoroacetic Acid and Structures of a M onohydrate and a Tetrahydrate [3]  
 Abstract    The liquidus and solidus lines of the quasi binary system CF3C O O H —H20 were determined by low temperature difference thermal analysis and the resulting phase relations controlled by X-ray powder diffraction. Formation of a monohydrate and a tetrahydrate, melting congruently at —43 and —16 °C, respectively, is confirmed. In addition a metastable form of the monohydrate and a low temperature form of the tetrahydrate, stable below —47 °C, are indicated. The crystal struc­ tures of the stable high temperature forms were determined. From these the monohydrate (tetra­ gonal, space group I42d, Z = 16) is a true acid hydrate, C F ,C 0 0 H H 20 . and the tetrahydrate (triclinic, P I, Z -2) a hydrated oxonium salt, (H 50 2) + [H(CF3COO)2]~ • 6 H:0 . 
  Reference    Z. Naturforsch. 39b, 298—3 (1984); eingegangen am 8. November 1983 
  Published    1984 
  Keywords    Trifluoroacetic Acid, Hydrates, Phase Diagram, Crystal Structure, Hydrogen Bonding 
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 Identifier    ZNB-1984-39b-0298 
 Volume    39 
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