bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mg2[BN2]Cl and Mg8[BN2]5I: Novel Magnesium Nitridoborate Halides — Syntheses, Crystal Structures, and Vibrational Spectra
Authors: Somer Mehmet , Kütükcü Mehmet Nuri , Gil Raul Cardoso , Borrmann Horst , Carrillo‐Cabrera Wilder 
Published: June 2004

AbstractThe title compounds have been synthesized at 1473 K from stoichiometric mixtures of the binary components Mg3N2, MgX2 (X = Cl, I) and BN in arc‐welded steel ampoules encapsulated in evacuated silica tubes. Mg2[BN2]Cl (1) and Mg8[BN2]5I (2) crystallize in the orthorhombic space groups Pbca (no. 61) and Imma (no. 74), respectively, with a = 6.6139(8)Å, b = 9.766(1)Å, c = 10.600(1)Å, Z = 8 for 1 and a = 13.535(3)Å, b = 9.350(2)Å, c = 11.194(2)Å, Z = 4 for 2. The crystal structures are characterized mainly by Mg6 trigonal prisms which are condensed to 3D frameworks in different ways. Part of the trigonal prisms are centered by the [N—B—N]3— anions and other voids in the framework by the X— anions. The magnesium environment around Cl— is a very distorted monocapped trigonal prism (CN = 6+1) and that of I— is a bicapped heptagonal prism (CN = 14+2). The bond lengths and bond angles for the relevant [BN2]3— anions are d(B—N) = 1.330 — 1.338Å, ∠N—B—N = 175.8° in 1 and d(B—N) = 1.330 — 1.339Å, ∠N—B—N = 176.8° — 178.0° in 2.The vibrational spectra of the title compounds have been recorded and interpreted based on the D∞h symmetry of the relevant [N—B—N]3— groups considering the site symmetry splitting.
Ein dreikerniger Zinkkomplex mit ZnS4‐, ZnS3O‐ und ZnS2NO‐Koordinationen
Authors: Schneider Astrid , Vahrenkamp Heinrich 
Published: June 2004

AbstractDie Reaktion des Tris(thioimidazolyl)borat‐Komplexes [TttBuZn‐OClO3] mit 2‐Pyridylbenzylalkohol (PBAH) liefert die Verbindung [(TttBu)3Zn3(PBA)] (ClO4)2. In dem dreikernigen Komplexkation verbrücken Tris(thioimidazolyl)borat‐Liganden in der Regenschirm‐Konformation die Zinkionen, die die drei verschiedenen Koordinationen ZnS4, ZnS3O und ZnS2NO haben.
The Crystal Structure of [Pt(NH3)4][PtI4]: Comparison with Magnus' Green Salt
Authors: Casas José S. , Parajó Yolanda , Romero Yago , Sánchez–González Angeles , Sordo José , Vázquez–López Ezequiel M. 
Published: June 2004

AbstractThe structure of the compound [Pt(NH3)4][PtI4] was studied by X‐ray diffractometry at 293 K (r. t.) and at 173 K. The structure is isotypic with that of Magnus' green salt and is unchanged at low temperature except for a slight contraction of the unit cell [tetragonal, P4/mnc; a = b = 9.8024(10) and c = 6.9311(10)Å at r. t; a = b = 9.764(3), c = 6.875(3)Å at 173 K]. It consists of [Pt(NH3)4]2+ cations and [PtI4]2− anions in which the platinum atoms are tetracoordinated by four ammine N or four I atoms in square‐planar arrangements. At 173 K the intramolecular bond lengths are hardly modified, but the intermolecular stacking interaction Pt‐Pt is slightly shortened.
Die Kristallstruktur des Oxophosphazens [Ph3PNPPh2NP(O)Ph2]
Authors: Müller Christof , Massa Werner , Miekisch Thomas , Dehnicke Kurt 
Published: June 2004

AbstractCrystal Structure of the Oxophosphazene [Ph3PNPPh2NP(O)Ph2]Single crystals of [Ph3PNPPh2NP(O)Ph2] were obtained as a by‐product from the synthesis of [NaNPPh3]6 as a result of partial hydrolysis. According to the crystal structure determination the compound forms a molecular structure with a PNPNP chain with PN distances between 155.3(6) and 159.8(5) pm and PNP bond angles of 143.2(4) and 140.7(4)°. Space group P1¯, Z = 2, lattice dimensions at 213 K: a = 922.7(1); b = 1040.1(1); c = 1908.0(1) pm; α = 90.55(1)°; β = 103.01(1)°; γ = 92.87(1)°; R = 0.0859.
Beiträge zum Koordinationsverhalten von Oxidionen in anorganischen Feststoffen. IV [1] Darstellung, Kristallstruktur und spektroskopische Charakterisierung von NiP4O11 und CaNiP2O7
Authors: Funke M. , Blum M. , Glaum R. , ElBali B. 
Published: June 2004

AbstractDurch Kristallisation aus der Schmelze werden Einkristalle von NiP4O11 und CaNiP2O7 erhalten. Diese erlauben Verfeinerungen der Kristallstrukturen (NiP4O11: C1¯, Z = 8, a = 12, 753(4)Å, b = 12, 957(3)Å, c = 10, 581(4)Å, α = 89, 42(2)°, β = 116, 96(2)°, γ = 90, 20(2)°, R1 = 0, 027, wR2 = 0, 072 für 3058 Io > 2σ (Io), 3291 unabhängige Reflexe, 290 Variable; CaNiP2O7: P1¯, Z = 2, a = 6, 433(3)Å, b = 6, 536(4)Å, c = 6, 515(2)Å, α = 66, 4(2)°, β = 87, 5(2)°, γ = 82, 7(2)°, R1 = 0, 026, wR2 = 0, 062 für 1624 Io > 2σ (Io), 2189 unabhängige Reflexe, 101 Variable) wie auch die Messung polarisierter Einkristallabsorptionsspektren (6000 — 32000 cm—1).NiP4O11 ist isotyp zu einer Reihe von Ultraphosphaten MP4O11 (M = Mn, Fe, Co, Cu, Zn, Cd) mit einem zweidimensionalen Netzwerk aus zehngliedrigen Phosphatringen. CaNiP2O7 vervollständigt die Serie von Diphosphaten CaMP2O7 (M = Cr — Zn). Die Ni2+‐Ionen sind in den beiden Phosphaten verzerrt‐oktaedrisch koordiniert. Die elektronischen Übergänge in den Chromophoren [Ni2+O6] werden durch Modellrechnungen im Rahmen des angular overlap model (AOM) gut wiedergegeben. Die Anpassungen der berechneten Elektronenübergänge an die beobachteten liefern eσ, norm(2, 0Å) = 3690 cm—1 und B = 896 cm—1 (C/B = 4, 2) für CaNiP2O7 sowie eσ, norm(2, 0Å) = 4150 cm—1 und B = 948 cm—1 (C/B = 4, 2) für NiP4O11 (Δo(CaNiP2O7) = 6800 cm—1; Δo(NiP4O11) = 7100 cm—1).
Electron Microscopy Characterization of Silicon Dioxide Nanotubes
Authors: Krumeich F. , Wark M. , Ren L. , Muhr H.‐J. , Nesper R. 
Published: June 2004

AbstractWell‐developed crystals of [Pt(NH3)4](HCO3)2are employed as template for the synthesis of silicon dioxide nanotubes (SiO2‐NTs). Silicon dioxide, which is produced by a sol‐gel reaction, coats the surface of these crystals and builds up the nanotube walls. In the final step, the Pt‐salt fibers are thermally decomposed and auto‐reduced to metallic Pt nanoparticles. Scanning and transmission electron microscopy (SEM and TEM) investigations of the product confirm the formation of silicon dioxide nanotubes in high yield. The tube walls consist of amorphous silicon dioxide. The tube length generally is 0.5 — 3 μm, while the thickness varies in two distinct ranges: thick tubes have a diameter of 100 — 500 nm and thin ones of approximately 50 nm. Most of the NTs are filled with Pt particles, but others, typically the larger ones with open tube ends, obviously are empty. Presumably, open ends cause the observed Pt loss. In closed SiO2‐NTs, Pt forms as ca. 10 nm large particles in the tube core and as 1 — 2 nm large particles inside the tube walls.
Preparation and Crystal Structures of the Hydrous Mercury Tellurates, HgII(H4TeVIO6) and HgI2(H4TeVIO6)(H6TeVIO6)·2H2O
Authors: Weil Matthias 
Published: June 2004

AbstractSingle crystals of HgII(H4TeVIO6) (colourless to light‐yellow, rectangular plates) and HgI2(H4TeVIO6)(H6TeVIO6)·2H2O (colourless, irregular) were grown from concentrated solutions of orthotelluric acid, H6TeO6, and respective solutions of Hg(NO3)2 and Hg2(NO3)2. The crystal structures were solved and refined from single crystal diffractometer data sets (HgII(H4TeVIO6): space group Pna21, Z = 4, a =10.5491(17), b = 6.0706(9), c = 8.0654(13)Å, 1430 structure factors, 87 parameters, R[F2 > 2σ(F2)] = 0.0180; HgI2(H4TeVIO6)(H6TeVIO6)·2H2O: space group P1¯, Z = 1, a = 5.7522(6), b = 6.8941(10), c = 8.5785(10)Å, α = 90.394(8), β = 103.532(11), γ = 93.289(8)°, 2875 structure factors, 108 parameters, R[F2 > 2σ(F2)] = 0.0184). The structure of HgII(H4TeVIO6) is composed of ribbons parallel to the b axis which are built of [H4TeO6]2— anions and Hg2+ cations held together by two short Hg—O bonds with a mean distance of 2.037Å. Interpolyhedral hydrogen bonding between neighbouring [H4TeO6]2— groups, as well as longer Hg—O bonds between Hg atoms of one ribbon to O atoms of adjacent ribbons lead, to an additional stabilization of the framework structure. HgI2(H4TeVIO6)(H6TeVIO6)·2H2O is characterized by a distorted hexagonal array made up of [H4TeO6]2— and [H6TeO6] octahedra which spread parallel to the bc plane. Interpolyhedral hydrogen bonding between both building units stabilizes this arrangement. Adjacent planes are stacked along the a axis and are connected by Hg22+ dumbbells (d(Hg—Hg) = 2.5043(4)Å) situated in‐between the planes. Additional stabilization of the three‐dimensional network is provided by extensive hydrogen bonding between interstitial water molecules and O and OH‐groups of the [H4TeO6]2— and [H6TeO6] octahedra. Upon heating HgI2(H4TeVIO6)(H6TeVIO6)·2H2O decomposes into TeO2 under formation of the intermediate phases HgII3TeVIO6 and the mixed‐valent HgIITeIV/VI2O6.
Polymorphism of Ph2P(CH2Py)(NSiMe3) and the Staudinger Reaction of Ph2P(CH2Py) with Hydrogenazide1)
Authors: Murso Alexander , Stalke Dietmar 
Published: June 2004

AbstractA new polymorph of the iminophosphorane Ph2P(CH2Py)(NSiMe3), (1), is compared to a just recently published. The reaction of the starting material, the phosphane Ph2P(CH2Py) with N3SiMe3 in the presence of water gives [Ph2P(CH2Py)(NH2)][N3], (2). A comparison of the structural and NMR parameters of 2 with previously reported derivatives of 1, suggests that 2 is best described as a phosphonium salt in which the negatively charged imino nitrogen atom is protonated, according to [Ph2(CH2Py)P+—NH2][N3]—, rather than as an iminiumphosphane salt [Ph2(CH2Py)P=+NH2][N3]—.
Yb2+3—xPd12—3+xP7 (x = 0.40): Different Ytterbium Species in a Substituted Structural Motif of the Zr2Fe12P7 Type
Authors: Budnyk S. , Prots Yu. , Schmidt M. , Schnelle W. , Kuz'ma Yu. , Grin Yu. 
Published: June 2004

AbstractThe new compound Yb2+3—xPd12—3+xP7 x = 0.40(4)) was synthesized by sintering of a mixture of elemental components at 1100 °C with subsequent annealing at 800 °C. The crystal structure of Yb2+3—xPd12—3+xP7 was solved and refined from X‐ray single‐crystal diffraction data: space group P6¯, a = 10.0094(4)Å, c = 3.9543(2)Å, Z = 1; R(F) = 0.022 for 814 observed unique reflections and 38 refined parameters. The atomic arrangement reproduces a structure motif of the hexagonal Zr2Fe12P7 type in which one of the transition metal positions is substituted predominantly by ytterbium (Yb : Pd = 0.86(1) : 0.14). The ytterbium atoms are embedded in the 3D polyanion formed by palladium and phosphorus atoms. Two different environments for ytterbium atoms are present in the structure. Magnetic susceptibility measurements and XAS spectroscopy at the Yb LIII edge show the presence of ytterbium in two electronic configurations, 4ƒ13 and 4ƒ14. The following model was derived. Ytterbium atoms in the 3k site are in the 4ƒ13 state, the two remaining positions contain ytterbium in intermediate‐valence states, giving totally 79 % ytterbium in the 4ƒ13 electronic configuration.
A CHEMICAL STUDY OF THE SPECIFIC ELEMENTS OF TUBERCULIN. I
Authors: Mueller J. Howard 
Published: June 2004

1. The specific precipitin reaction and the skin reaction given by old tuberculin are attributable to two separate substances present in this material. The cause of the reaction first mentioned is a non-protein gum which will be fully described in the following paper. The cause of the skin reaction is probably but not surely a protein.
2. Methods which have been suggested for the standardization of tuberculin by precipitin or complement fixation reactions should be revised.
STUDIES ON X-RAY EFFECTS
Authors: Hance Robert T. , Clark Harry 
Published: June 2004

Two races of paramecium were submitted for varying lengths of time to x-radiation and a large number of individuals were observed to determine the effect on the rate of division. The division rate of both races suffered a slight initial depression lasting for 2 to 5 days following the exposure. This depression is followed by complete recovery.
Within rather wide limits the length of the exposure has, in these experiments, made no appreciable difference. Apparently the maximum effect of the x-rays is produced by relatively short exposures. Continued radiation produces little further change until exposures of 3 and 4 hours are used, when precisely the opposite results are obtained from those obtained with shorter exposures.
Doses repeated at various intervals have in general failed to interfere more markedly with the division rate than a single dose. Repeated radiation causes the cells to become slightly swollen without apparent interference with their viability.
THE LIMITED NEUROTROPIC CHARACTER OF THE ENCEPHALITIS VIRUS (ST. LOUIS TYPE) IN SUSCEPTIBLE MICE
Authors: Webster Leslie T. , Clow Anna D. 
Published: June 2004

1. St. Louis encephalitis virus injected intracerebrally into susceptible mice multiplies there to reach a titre of 109 intracerebral lethal doses. It is found also in the blood in small amounts immediately following injection and preceding death.
2. Injected intraperitoneally or subcutaneously the virus circulates in the blood for several hours and survives in the spleen for days. It does not multiply in the brain and cause encephalitis, however, unless overwhelming doses are injected or the brain is traumatized.
3. Virus dropped into the nares is demonstrable in the olfactory bulbs at 24 hours, in the piriform lobes at 24 to 48 hours, in the remainder of the brain at 3 days, and in the spinal cord at 4 days. In the brain it reaches a titre of 109 in 6 days. Virus is not readily demonstrable in the blood but is present in the spleen after 48 hours.
4. Virus survives and is capable of multiplying in the spleen.
5. Lesions following nasal instillation of virus appear first in the olfactory bulbs on the 3rd day, in the piriform lobes on the 4th, and in Ammon's horn on the 5th day. The character of the lesions in order of their appearance is exudation of mononuclear cells about superficial blood vessels and in the pia, hyperplasia of the endothelium of the pia, and necrosis of nerve cells of the olfactory tract.
STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL
Authors: Nelson John B. 
Published: June 2004

A strain of fowl coryza of slow onset was carried through 20 successive passages in susceptible birds over a period of approximately 19 months. During this period it retained its initial characteristics as did also a coryza of rapid onset which was similarly maintained. 88 per cent of 72 birds infected with the coryza of slow onset showed a nasal discharge after an incubation period of 12 days or more; the actual limits being 9 to 31 days. 98 per cent of 54 birds infected with the coryza of rapid onset showed a nasal discharge on the 1st or 2nd day after injection. The duration of both coryzas was prolonged.
Bacteriological examination indicated that Hemophilus gallinarum which is invariably present in the nasal exudate of birds infected with the coryza of rapid onset is not associated with the coryza of slow onset.
STUDIES ON THE COMMON COLD
Authors: Dochez A. R. , Mills K. C. , Kneeland Yale 
Published: June 2004

1. Studies of the cultivation of the virus of common cold in tissue medium, and the capacity of the culture virus to induce infection in human volunteers are reported.
2. Detailed descriptions are given of the methods employed to isolate the virus, preserve and cultivate it, and to test its activity in human volunteers.
3. The virus of common cold can easily be isolated from properly selected patients and cultivated in tissue medium.
4. When kept in the original nasopharyngeal washings, the virus will survive at ice box temperature under anaerobic conditions for at least 13 days.
5. If the nasopharyngeal washings are frozen and dried in vacuo, the virus retains its activity for at least 4 months.
6. The virus of common cold has been proven to multiply in medium containing chick embryo tissue. Such cultures retain their capacity to produce typical infections in human beings for many transfers involving a period of several months. Attempts to cultivate the virus have been successful in seven out of eight instances.
7. Prolonged cultivation of the virus in tissue medium eventually leads to a loss of activity.
8. Strains of virus under cultivation maintain their potency best when transfers are made at 2 and 3 day intervals.
9. After removal from the incubator a culture of virus rapidly becomes inactive whether it be kept under seal in the ice box or frozen and dried in vacuo.
10. The destructive action of the medium can be prevented if the culture is mixed with gum acacia before freezing and drying in vacuo.
THE CULTIVATION OF TISSUES FOR PROLONGED PERIODS IN SINGLE FLASKS
Authors: Parker Raymond C. 
Published: June 2004

1. Fragments of breast muscle from a 12 day old chick embryo have been kept alive in single flasks for an entire year without being transferred. The nutrient materials were supplied by frequent applications of adult fowl serum diluted with Tyrode solution.
2. When fragments of fixed tissues are cultivated in serum, cell multiplication and cell death are both reduced to an extremely low level.
3. The presence of a plasma coagulum is not essential to the continued survival and further development of tissues cultivated inserum.
4. The fibrinogen, prothrombin, and fibrin of coagulated plasma are not essential to the development of connective tissue fibers in vitro.
PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES: EFFECT OF BACTERIAL FILTRATES INJECTED INTRAVASCULARLY UPON REACTIONS TO ANTIGEN + ANTIBODY COMPLEXES
Authors: Shwartzman Gregory 
Published: June 2004

Rabbits were sensitized by a single intravenous injection of horse serum 6 days prior to the experiments. In these rabbits there appeared hemorrhagic and necrotic reactions in sites of intradermal tests with horse serum when the tests were preceded by 1 hour, or followed 18 to 24 hours later by an intravenous injection of potent bacterial filtrates. The skin-preparatory and reacting potencies of the filtrates were titrated by means of the phenomenon of local skin reactivity to bacterial filtrate. The experiments demonstrated that the ability of bacterial filtrates to elicit reactions in the antigen injected sites in sensitized animals is strictly conditioned by their skin-preparatory potency and seems to be quite independent of their provocative potency. Combinations of animal protein antigens with homologous antisera, which are endowed with provocative potency but are totally devoid of skin-preparatory potency, fail to elicit reactions in antigen-injected sites.
The various methods of elicitation of the phenomenon of local tissue reactivity are summarized and discussed in the text.
THE RELATION BETWEEN ANTIANAPHYLAXIS AND ANTIBODY BALANCE
Authors: Morris Marion C. 
Published: June 2004

It has been shown that antianaphylaxis is not caused by a partial saturation of cellular or humoral antibodies by the following facts.
1. Guinea pigs passively sensitized with anti-horse or antipneumococcus serum and specifically desensitized do not manifest as great a reactivity upon resensitization with the same antiserum as upon the original sensitization.
2. Guinea pigs passively sensitized with anti-Friedländer Type B serum or antipneumococcus Type II serum and specifically desensitized do not attain the same degree of reactivity as normal animals when passively sensitized with anti-horse serum.
3. Guinea pigs passively sensitized with anti-Friedländer Type B serum and desensitized with the specific carbohydrate remain as resistant to infection with Friedlander's bacillus Type B as undesensitized guinea pigs. Since in this case, at least, it is agreed that type-specific immunity and type-specific hypersensitiveness are due to the same type-specific antibody, a change in anaphylactic response should be accompanied by a change in immune response, provided this change depends on antibody balance.
4. A determination of the antibody content of the serum of sensitized as well as of desensitized guinea pigs by mouse protection tests indicates that a loss of reactivity in desensitized animals cannot be adequately accounted for on the basis of depletion of circulating antibody.
These experiments suggest that hypersensitiveness and resistance are different manifestations of the same antigen-antibody reaction while antianaphylaxis is a state of refractoriness which is due neither to excess of circulating antibody nor to antibody depletion, but is the result of secondary changes the true nature of which is still not definitely established.
VITAMIN C THERAPY AND PROPHYLAXIS IN EXPERIMENTAL POLIOMYELITIS
Authors: Jungeblut Claus W. 
Published: June 2004

1. A group of 34 monkeys were infected intracerebrally with 0.1 cc. of a 10 per cent virus suspension. Following infection, 9 animals were treated with daily injections of 700 to 100 mg., 16 with 50 to 10 mg. and 9 with 5 mg. of vitamin C for a period of 2 weeks. In the whole group there were 6 animals that survived without showing any evidence of paralysis. 2 of these had received 50 to 10 mg. while 4 had received 5 mg. All of 19 untreated control monkeys, infected simultaneously with the same amount of virus, developed paralysis.
2. Another group of 6 monkeys were infected intracerebrally with 0.05 cc. of virus. Following infection, one animal was treated in the same manner with 25 mg. and 5 with 5 mg. of vitamin C. In the whole group there was one animal that survived without showing any evidence of paralysis. This animal had received 5 mg. All of 7 untreated control monkeys, infected simultaneously with the same amount of virus, developed paralysis.
3. A third group of 22 monkeys were infected intracerebrally with 0.01 cc. of virus. Following infection, one animal was treated in the same manner with 100 mg., 2 with 50 to 10 mg., and 19 with 5 mg. of vitamin C. In the whole group there were 12 animals that survived without showing any evidence of paralysis. One of these had received 10 mg., while 11 had received 5 mg. Of 12 untreated control monkeys, infected simultaneously with the same amount of virus, 2 failed to show any paralytic symptoms and 10 developed paralysis.
4. A summary of the results obtained in all three groups shows: (a) that among a total of 62 treated monkeys, 19 survived without paralysis and 43 succumbed to the disease, while of a total of 38 untreated controls, only 2 failed to develop paralysis and 36 succumbed to the disease; (b) that treatment with large doses of vitamin C was without any beneficial effect (all 10 monkeys which had received 700 to 100 mg. developing paralysis, that the administration of intermediate doses was followed by occasional survival without paralysis of the treated animal (3 monkeys surviving of a total of 19 which had received 50 to 10 mg.), and that nearly one-half of the animals which had received small doses escaped the disease (16 monkeys surviving of a total of 33 which had received 5 mg.).
5. Attempts to protect monkeys against subsequent intracerebral infection by the prophylactic administration of vitamin C, either per os or parenterally, have produced negative results.
6. The pathogenesis of infantile paralysis is discussed in the light of the experimental findings and the possibility is suggested that vitamin C represents one of the deficiency factors in the susceptibility problem of the human disease.