Phosphor(V)-nitride durch Hochdruck-Hochtemperatur-Synthese

1. Development and establishment of the high-pressure high-temperature synthesis as a broad approach to nitridophosphates. In this thesis for the first time a broad access to nitridophosphates was developed and therefore the basis for a systematic investigation of this class of compounds was established. It was shown, that under high-pressure conditions (> 3 GPa) using a belt or Walker module crystalline nitridophosphates can be obtained by reaction of phosphorus(V) nitride with alkaline or earth alkaline azides at temperatures of 1200-1600 °C. Thus the possibilty to suppress eliminiation of N2 from nitridophosphates, which occurs at 800 °C under atmospheric pressure, was proved by use of high-pressure conditions. Thereby the maximum temperature in synthesis of nitridophosphates was approximately doubled. A raise of the maximum temperature during the synthesis leads to much better crystallization conditions. Hence the main problem in synthesis of crystalline nitridophosphates, which consists of bad crystallisation conditions due to limited maximum reaction temperature, was solved and the number of the crystallographically well characterized ternary phosphorus(V) nitrides was doubled from nine to eighteen. Especially the number of highly condensed nitridophosphates (molar ratio P : N > 1 : 2) could be raised from three to nine and a second modification of the binary phosphorus(V) nitride P3N5 was obtained. Consequently the high-pressure high-temperature synthesis can be seen as the first widely applicable approach to nitridophosphates. Due to the hermetically sealed reaction cell precise modulation of the P-N framework by systematic variation of the P3N5 : azide molar ratio in the starting materials. Moreover under high-pressure conditions the reaction time was reduced dramatically compared to conventional synthesis. While using conventional methods several hours or days are needed for quantitative reactions, reactions under high pressure conditions succeed in 5-15 min. At the beginning of the work the apparatus for the high-pressure experiments did not exist within the laboratory equipment of our research group. The success of the first experiments (synthesis of NaP4N7, KP4N7, RbP4N7, CsP4N7), which were performed in cooperation with Evers, significantly contributed to the aquisition of the 1000 t-press installed by Huppertz, and the introduction of the multianvil high-pressure technique at the University of Munich (LMU). 2. NaP4N7, KP4N7, RbP4N7, and CsP4N7. The nitridophosphates NaP4N7, KP4N7, RbP4N7, and CsP4N7 were synthesized by reaction of P3N5 with the respective alkaline azide in the molar ratio MN3 : P3N5 = 3 : 4 (M = Na, K, Rb, Cs) at approximately 40 kbar and 1300 °C using a belt module. NaP4N7 (C2/c, a = 1233.45(4), b = 852.30(3), c = 513.97(1) pm, b = 102.572(2)°, Z = 4, Rp = 0.0772, wRp = 0.1077, RF = 0.0718) crystallizes isotypic to CaAl4O7 in a three-dimensional network structure of corner-sharing PN4 tetrahedra with Na + ions in the channels. According to the formula ¥ 3 [(P [4] 4 N 5 [2] N 2 [3] ) - ] N [2] - and N [3] -bridges exist in a molar ratio 5 : 2. KP4N7 (Pnma, a = 1222.72(2), b = 984.25(2), c = 466.24(1) pm, Z = 4, Rp = 0.0865, wRp = 0.1113, RF = 0.0821), RbP4N7 (a = 1231.07(2), b = 989.46(1), c = 468.44(1) pm, Z = 4, Rp = 0.0350, wRp = 0.0462, RF = 0.0589), and CsP4N7 (a = 1242.91(3), b = 997.63(3), c = 471.33(2) pm, Z = 4, Rp = 0.0524, wRp = 0.0646, RF = 0.0494) crystallize isotypic to the mineral barylite BaBe2Si2O7 in a three-dimensional network structure from corner-sharing PN4 tetrahedra with the alkaline ions in the channels. According to the formula ¥ 3 [(P [4] 4 N 5 [2] N 2 [3] ) - ] N [2] - and N [3] -bridges exist in a molar ratio 5 : 2. Using the obtained crystallographic data of MP4N7 (M = Na, K, Rb, Cs) MAPLE and CHARDI calculations as well as calculations based on the bond-length bond-strength concept were carried out and discussed. The radiographically obtained results were confirmed. The compounds were characterized by IR- and 31 P-MAS NMR-spectroscopy (d = -23.5, -25.0 (NaP4N7); -0.4, -1.7 (KP4N7), -19.6, -28.2 (RbP4N7), -21.6, -31.9 ppm (CsP4N7)). Thermogravimetric examinations under inert gas conditions revealed the thermal decomposition temperature of the compounds, which is about 850-900 °C. 3. Rb3P6N11 and Cs3P6N11. The nitridophosphates Rb3P6N11 and Cs3P6N11 were synthesized by reaction of P3N5 with the respective alkaline azide in the molar ratio MN3 : P3N5 = 3 : 2 (M = Rb, Cs) using a Walker module at approximately 35 kbar and 1300 °C. Rb3P6N11 (P4132, a = 1049.74(1) pm, Z = 4, Rp = 0.0979, wRp = 0.1077, RF = 0.0612) and Cs3P6N11 (P4132, a = 1065.15(1) pm, Rp = 0.0487, wRp = 0.0618, RF = 0.0812) crystallize isotypic to K3P6N11 in a three-dimensional network structure of corner-sharing PN4 tetrahedra with the alkaline ions in the channels. According to the formula ¥ 3 [(P 6 [4] N 9 [2] N 2 [3] ) 3- ] N [2] - and N [3] -bridges exist in the molar ratio 9 : 2. Using the obtained crystallographic data of M3P6N11 (M = Rb, Cs) MAPLE and CHARDI calculations as well as calculations based on the bond-length bond-strength concept were carried out and discussed. The radiographically obtained results were confirmed. The compounds were characterized by IR- and 31 P-MAS NMR-spectroscopy (d = -7.4 (Rb3P6N11), -8.9 ppm (Cs3P6N11)). Thermogravimetric examinations under inert gas conditions revealed the thermal decomposition temperature of the compounds, which is about 850-900 °C. Temperature-dependant powder X-ray investigations revealed that Rb3P6N11 shows no thermal expansion between room temperature and 540 °C.4. NaPN2. The nitridophosphate NaPN2 was synthesized by reaction of P3N5 with NaN3 in the molar ratio NaN3 : P3N5 = 3 : 1 using a Walker module at approximately 35 kbar and 1300 °C. NaPN2 (I 4 2d, a = 497.21(2), c = 697.60(3) pm, Z = 4, Rp = 0.0502, wRp = 0.0649, RF = 0.0788) crystallizes isotypic to LiPN2 in a three-dimensional network structure of corner-sharing PN4 tetrahedra with the Na + ions in the channels. According to the formula ¥ 3 [(P [4] N 2 [2] ) - ] N [2] -bridges exist exclusively. Using the obtained crystallographic data of NaPN2, MAPLE and CHARDI calculations as well as calculations based on the bond-length bond-strength concept were carried out and discussed. The radiographically obtained results were confirmed. The compound was characterized by IR- and 31 P-MAS NMR-spectroscopy (d = -15.0 ppm). Thermogravimetric examinations under inert gas conditions revealed the thermal decomposition temperature of the compound, which is about 900 °C. 5. CaP2N4 and SrP2N4. The nitridophosphates CaP2N4 und SrP2N4 were obtained by reaction of Ca(N3)2 and Sr(N3)2 with P3N5 (molar ratio M(N3)2 : P3N5 = 3 : 2) at 35 kbar and 1300 °C in a Walker module. A structure model could be obtained from X-ray powder data. CaP2N4 (P6322, a = 972.11(1) pm, c = 785.90(1) pm, Z = 8, Rp = 0.059, wRp = 0.079, RF = 0.174) and SrP2N4 (P6322, a = 987.44(1), c = 785.90(1) pm, Z = 8, Rp = 0.075, wRp = 0.098, RF = 0.115) crystallize isotypic in a network structure from corner-sharing PN4 tetrahedra with the alkaline earth ions within the channels. Perpendicular to [001] layers from condensed P6N6 sechser rings exists which are linked by P4N4 vierer rings and further P6N6 sechser rings forming the network structure. According to the formula ¥ 3 [(P [4] N 2 [2] ) - ] N [2] -bridges occur exclusively. Using the obtained crystallographic data of CaP2N4 and SrP2N4, MAPLE and CHARDI calculations as well as calculations based on the bond-length bond-strength concept were carried out and discussed. The radiographically obtained results were confirmed. The compounds were characterized by IR- and 31 P-MAS NMR-spectroscopy (d = -20.0, -15.9, -5.2, -3.6, - 2.6 (CaP2N4), -27.8, -23.4, -17.1, -15.5, -14.1 ppm (SrP2N4). Thermogravimetric examinations under inert gas conditions revealed the thermal decomposition temperature of SrP2N4, which is about 900 °C. CaP2N4 was stable up to 1000 °C. 6. g-P3N5. The synthesis of g-P3N5 was successfully carried out at 110 kbar and 1500 °C. In contrast to a-P3N5, which is exclusively build up from PN4 tetrahedera, g-P3N5 forms a three-dimensional network structure from PN4 tetrahedra and tetragonal PN5 pyramids. The tetragonal PN5 pyramid is a formerly unknown structural building unit. In the crystal- structure of g-P3N5 (Imm2, a = 1287.20(5), b = 261.312(6), c = 440.04(2) pm, Z = 2, Rp = 0.073, wRp = 0.094, RF = 0.048) rods of trans edge-sharing PN5 pyramids are condensed via vertice forming layers. These layers are linked by chains of corner-sharing tetrahedra. According to the formula ¥ 3 [P ] 4 [ 1 P ] 5 [ 2 N ] 2 [ 1 N ] 3 [ 4 ] N [2] and N [3] bridges occur in the molar ratio 1 : 4. Using the obtained crystallographic data of g-P3N5, MAPLE and CHARDI calculations as well as calculations based on the bond-length bond-strength concept were carried out and discussed. The radiographically obtained results were confirmed. The compound was characterized by IR- and 31 P-MAS NMR-spectroscopy (d = -11.9, -101.7 ppm). Thermogravimetric examinations under inert gas conditions revealed the thermal decomposition temperature of the compound, which is about 900 °C. The Vickers hardness was determined with a value of 9.7 GPa. 7. Hexaaminodiphosphazenium-bromide, -nitrate, and -toluenesulfonate. It was shown, that the hexaaminodiphosphazenium-salts [(NH2)3PNP(NH2)3]Br, [(NH2)3PNP(NH2)3] [NO3], and [(NH2)3PNP(NH2)3][CH3C6H4SO3] are accessible by anion exchange in water using [(NH2)3PNP(NH2)3]Cl as starting material. The structures of these compounds were obtained from single crystals, which were obtained from an acetonitrile solution in a temperature gradient ([(NH2)3PNP(NH2)3]Br: P 1 , a = 596.2(1), b = 744.5(1), c = 1114.4(1) pm, a = 108.78(1), b = 104.18(1), g = 90.64(1)°, R1 = 0.048, wR2 = 0.104; [(NH2)3PNP(NH2)3][NO3]: P 1 , a = 550.9(1), b = 796.3(1), c = 1115.7(1) pm, a = 94.45(1), b = 99.55(1), g = 101.53(1)°, R1 = 0.033, wR2 = 0.095; [(NH2)3PNP(NH2)3][CH3C6H4SO3]: P21/c, a = 804.1(1), b = 596.1(1), c = 3218.7(3) pm, b = 94.59(1)°, R1 = 0.052, wR2 = 0.136). The compounds crystallize in structures with discrete [(NH2)3PNP(NH2)3] + -ions and the corresponding anions. [(NH2)3PNP(NH2)3]Br is isotypic to [(NH2)3PNP(NH2)3]Cl. Between the ions many hydrogen bonds exist. In [(NH2)3PNP(NH2)3]Br the [(NH2)3PNP(NH2)3] + -ion occurs in a staggered conformation, while in [(NH2)3PNP(NH2)3][NO3] an ecliptic conformation is preferred. In [(NH2)3PNP(NH2)3][CH3C6H4SO3] the gauche-conformation exists. It was shown by Extended Hückel calculations, that no significant rotation barriers exist between the conformations. The compounds were characterized by IR and 31 P NMR-spectroscopy (d = -15.0 ppm). The thermal behaviour of the compounds was examined by thermogravimetry.1. Entwicklung und Etablierung der Hochdruck-Hochtemperatur-Synthese als breiten Zugang zu Nitridophosphaten. Im Rahmen der Dissertation gelang es erstmals, ein breit anwendbares Synthesekonzept zur Darstellung von Nitridophosphaten zu entwickeln und so die Grundlage zur systematischen Erschließung dieser Substanzklasse zu legen. Es konnte gezeigt werden, daß unter Hochdruck-Bedingungen (> 3 GPa) bei Verwendung eines Belt- oder Walker-Moduls kristalline Alkali- und Erdalkali-nitridophosphate durch Umsetzung des binären Phosphor(V)-nitrids P3N5 mit Alkali- und Erdalkaliaziden bei Temperaturen von 1200 °C bis ca. 1600 °C darstellbar sind. Dadurch wurde bewiesen, daß bei Synthesen unter Hochdruck die thermische Zersetzung durch irreversible Abspaltung von N2 aus Nitridophosphaten, welche bei Normaldruck bereits bei ca. 800 °C stattfindet, unterdrückt werden kann. Es gelang somit durch Anwendung von Hochdruck, die maximale Synthesetemperatur ungefähr zu verdoppeln. Dies hat deutlich verbesserte Kristallisationsbedingungen zu Folge. Das Hauptproblem bei konventionellen Synthesen von Nitridophosphaten, nämlich ungünstige Kristallisationsbedingungen infolge limitierter Synthesetemperatur, konnte somit beseitigt und infolgedessen die Zahl der bekannten kristallographisch eindeutig charakterisierten ternären Phosphor(V)-nitride von neun auf achtzehn verdoppelt werden. Insbesondere wurde die Zahl der bekannten hochkondensierten Nitridophosphate (molares Verhältnis P : N > 1 : 2) von drei auf neun erhöht sowie eine neue Modifikation des binären Phosphor(V)-nitrids P3N5 erhalten. Daher kann das im Rahmen der Dissertation entwickelte Hochdruck-Hochtemperatur-Synthesekonzept als das erste breit anwendbare Verfahren zur Darstellung von Nitridophosphaten angesehen werden. Es erlaubt aufgrund der hermetischen Abgeschlossenheit des Reaktionsraums zudem das genaue Einstellen des Kondensationsgrades im P-N-Gerüst des Nitridophosphates durch systematische Variation des molaren Verhältnisses von P3N5 und dem jeweiligen Azid im Eduktgemenge. Weiterhin wurde gezeigt, daß unter den beschriebenen Hochdruck-Hochtemperaturbedingungen die Reaktionszeiten gegenüber konventionellen Synthesemethoden drastisch verkürzt werden können. Während konventionelle Nitridophosphat-Synthesen eine Reaktionszeit von mehreren Stunden bis Tagen benötigen, verlaufen die Umsetzungen unter Hochdruckbedingungen bereits bei Reaktionszeiten von 5-15 min quantitativ. Die für die Hochdrucksynthesen erforderlichen Apparaturen standen am Anfang der Dissertation innerhalb des Arbeitskreises nicht zur Verfügung. Der Erfolg der ersten Synthesen (NaP4N7, KP4N7, RbP4N7, CsP4N7), welche in Zusammenarbeit mit Evers durchgeführt wurden, trugen wesentlich zur Anschaffung der 1000 t-Hochdruckpresse, deren Aufbau durch Huppertz erfolgte, und zur Einführung der Multianvil-Hochdrucktechnik an der LMU München bei. 2. NaP4N7, KP4N7, RbP4N7 und CsP4N7. Die Nitridophosphate NaP4N7, KP4N7, RbP4N7 und CsP4N7 wurden durch Umsetzung des jeweiligen Alkaliazids mit P3N5 im molaren Verhältnis MN3 : P3N5 = 3 : 4 (M = Na, K, Rb, Cs) in einem Belt-Modul bei ca. 40 kbar und 1300 °C synthetisiert. NaP4N7 (C2/c, a = 1233,45(4), b = 852,30(3), c = 513,97(1) pm, b = 102,572(2)°, Z = 4, Rp = 0,0772, wRp = 0,1077, RF = 0,0718) kristallisiert isotyp zu CaAl4O7 in einer dreidimensionalen Gerüststruktur aus eckenverknüpften PN4-Tetraedern. Gemäß ¥ 3 [(P [4] 4 N 5 [2] N 2 [3] ) - ] existieren sowohl N [2] - als auch N [3] -Brücken im molaren Verhältnis 5 : 2. Die Na + -Ionen befinden sich in den Kanälen des P-N-Gerüstes. KP4N7 (Pnma, a = 1222,72(2), b = 984,25(2), c = 466,24(1) pm, Z = 4, Rp = 0,0865, wRp = 0,1113, RF = 0,0821), RbP4N7 (a = 1231,07(2), b = 989,46(1), c = 468,44(1) pm, Z = 4, Rp = 0,0350, wRp = 0,0462, RF = 0,0589) und CsP4N7 (a = 1242,91(3), b = 997,63(3), c = 471,33(2) pm, Z = 4, Rp = 0,0524, wRp = 0,0646, RF = 0,0494) kristallisieren isotyp zum Mineral Barylith BaBe2Si2O7 in einer Raumnetzstruktur aus eckenverknüpften PN4-Tetraedern. Gemäß ¥ 3 [(P [4] 4 N 5 [2] N 2 [3] ) - ] existieren sowohl N [2] als auch N [3] -Brücken im molaren Verhältnis 5 : 2. In den Kanälen der P-N-Gerüste befinden sich die jeweiligen Alkali-Ionen. Anhand der kristallographischen Daten wurden an MP4N7 (M = Na, K, Rb, Cs) kristallchemische Rechnungen mit dem MAPLE- und CHARDI- Konzept sowie Berechnungen auf der Basis des Bindungslängen-Bindungsstärken- Konzepts durchgeführt und diskutiert. Dabei wurden die röntgenographisch ermittelten Strukturen bestätigt. Die Verbindungen wurden IR-spektroskopisch sowie 31 P-MAS-NMR- spektroskopisch (d = -23,5, -25,0 (NaP4N7); -0,4, -1,7 (KP4N7), -19,6, -28,2 (RbP4N7), -21,6, -31,9 ppm (CsP4N7)) charakterisiert. Mit thermogravimetrischen Untersuchungen unter Inertgasbedingungen wurde der thermische Zersetzungspunkt der Verbindungen ermittelt, welcher jeweils bei ca. 850-900 °C liegt. 3. Rb3P6N11 und Cs3P6N11. Die Nitridophosphate Rb3P6N11 und Cs3P6N11 wurden durch Umsetzung des jeweiligen Alkaliazids mit P3N5 im molaren Verhältnis MN3 : P3N5 = 3 : 2 (M = Rb, Cs) bei 35 kbar und 1300 °C in einem Walker-Modul dargestellt. Rb3P6N11 (P4132, a = 1049,74(1) pm, Z = 4, Rp = 0,0979, wRp = 0,1077, RF = 0,0612) und Cs3P6N11 (P4132, a = 1065,15(1) pm, Rp = 0,0487, wRp = 0,0618, RF = 0,0812) kristallisieren isotyp zu K3P6N11 in einer Raumnetzstruktur aus eckenverknüpften PN4-Tetraedern, in dessen Hohlräumen sich die Alkali-Ionen befinden. Gemäß ¥ 3 [(P 6 [4] N 9 [2] N 2 [3] ) 3- ] existieren N [2] - und N [3] -Brücken im molaren Verhältnis 9 : 2. Anhand der kristallographischen Daten wurden an M3P6N11 (M = Rb, Cs) kristallchemische Rechnungen mit dem MAPLE- und CHARDI-Konzept sowie Berechnungen auf der Basis des Bindungslängen-Bindungsstärken-Konzepts durchgeführt und diskutiert. Dabei wurden die röntgenographisch ermittelten Strukturen bestätigt. Die Verbindungen wurden IR-spektroskopisch sowie 31 P-MAS-NMR-spektroskopisch (d = -7,4 (Rb3P6N11), -8,9 ppm (Cs3P6N11)) charakterisiert. Mit thermogravimetrischen Untersuchungen unter Inertgasbedingungen wurde der thermische Zersetzungspunkt der Verbindungen ermittelt, welcher jeweils bei ca. 850-900 °C liegt. Temperaturabhängige pulverdiffraktometrische Untersuchungen zeigten, daß sich die Verbindung Rb3P6N11 zwischen Raumtemperatur und 540 °C praktisch nicht thermisch ausdehnt. 4. NaPN2. Das Nitridophosphat NaPN2 wurde durch Umsetzung von NaN3 mit P3N5 im molaren Verhältnis NaN3 : P3N5 = 3 : 1 bei 35 kbar und 1000 °C in einem Walker-Modul dargestellt. NaPN2 (I 4 2d, a = 497,21(2), c = 697,60(3) pm, Z = 4, Rp = 0,0502, wRp = 0,0649, RF = 0,0788) kristallisiert isotyp zu LiPN2 in einer Raumnetzstruktur aus eckenverknüpften PN4-Tetraedern, in dessen Kanälen sich die Na + -Ionen befinden. Gemäß ¥ 3 [(P [4] N 2 [2] ) - ] existieren ausschließlich N [2] -Brücken. Anhand der kristallographischen Daten wurden an NaPN2 kristallchemische Rechnungen mit dem MAPLE- und CHARDI-Konzept sowie Berechnungen auf der Basis des Bindungslängen-Bindungsstärken- Konzepts durchgeführt und diskutiert. Dabei wurde die röntgenographisch ermittelte Struktur bestätigt. Die Verbindung wurde IR-spektroskopisch sowie 31 P-MAS-NMR-spektroskopisch (d = -15,0 ppm) charakterisiert. Mit thermogravimetrischen Untersuchungen unter Inertgasbedingungen wurde der thermische Zersetzungspunkt ermittelt, welcher bei ca. 900 °C liegt. 5. CaP2N4 und SrP2N4. Die Nitridophosphate CaP2N4 und SrP2N4 wurden durch Umsetzung von Ca(N3)2 bzw. Sr(N3)2 mit P3N5 im molaren Verhältnis M(N3)2 : P3N5 = 3 : 2 bei 35 kbar und 1300 °C in einem Walker-Modul dargestellt. Aus röntgenographischen Untersuchungen an Pulvern von CaP2N4 und SrP2N4 konnte ein Strukturmodell erhalten werden. CaP2N4 (P6322, a = 972,11(1), c = 785,90(1) pm, Z = 8, Rp = 0,059, wRp = 0,079, RF = 0,174) und SrP2N4 (P6322, a = 987,44(1), c = 819,48(1) pm, Z = 8, Rp = 0,075, wRp = 0,096, RF = 0,115) kristallisieren isotyp in einer Raumnetzstruktur aus eckenverknüpften PN4-Tetraedern, in dessen Kanälen sich die Erdalkali-Ionen befinden. Dabei sind senkrecht [001] verlaufende Schichten kondensierter P6N6-Sechserringe über P4N4-Viererringe sowie weitere P6N6-Sechserringe zum dreidimensionalen P-N-Gerüst verknüpft. Gemäß ¥ 3 [(P [4] N 2 [2] ) - ] existieren ausschließlich N [2] -Brücken. Anhand der kristallographischen Daten wurden an CaP2N4 und SrP2N4 kristallchemische Rechnungen mit dem MAPLE- und CHARDI-Konzept sowie Berechnungen auf der Basis des Bindungslängen-Bindungsstärken-Konzepts durchgeführt und diskutiert. Dabei wurden die röntgenographisch ermittelten Strukturen weitgehend bestätigt. Die Verbindungen wurden IR-spektroskopisch sowie 31 P-MAS-NMR-spektroskopisch (d = -20,0, -15,9, -5,2, -3,6, -2,6 (CaP2N4), -27,8, -23,4, -17,1, -15,5, -14,1 ppm (SrP2N4) charakterisiert. Die thermogravimetrischen Untersuchungen unter Inertgasbedingungen ergaben einen thermischen Zersetzungspunkt von SrP2N4 bei ca. 900 °C, während sich CaP2N4 bis 1000 °C als stabil erwies. 6. g-P3N5. Bei 110 kbar und 1500 °C gelang die Darstellung von g-P3N5, einer Hochdruckmodifikation von a-P3N5. Im Gegensatz zu a-P3N5, welches ausschließlich aus PN4-Tetraedern aufgebaut ist, bildet g-P3N5 eine dreidimensionale Raumnetzstruktur sowohl aus PN4-Tetraedern als auch aus tetragonalen PN5-Pyramiden. Das Strukturelement der tetragonalen PN5-Pyramide war bislang unbekannt. In der Kristallstruktur von g-P3N5 (Imm2, a = 1287,20(5), b = 261,312(6), c = 440,04(2) pm, Z = 2, Rp = 0,073, wRp = 0,094, RF = 0,048) sind Stäbe trans-kantenverknüpfer PN5-Pyramiden zu Schichten verknüpft. Diese sind wiederum über Ketten eckenverknüpfter PN4-Tetraeder zur Gesamtstruktur verknüpft. Gemäß ¥ 3 [P ] 4 [ 1 P ] 5 [ 2 N ] 2 [ 1 N ] 3 [ 4 ] existieren sowohl N [2] als auch N [3] -Brücken im molaren Verhältnis 1 : 4. Anhand der kristallographischen Daten wurden an g-P3N5 kristallchemische Rechnungen mit dem MAPLE- und CHARDI-Konzept sowie Berechnungen auf der Basis des Bindungslängen-Bindungsstärken- Konzepts durchgeführt und diskutiert. Dabei wurde die röntgenographisch ermittelte Struktur bestätigt. Die Verbindung wurde IR-spektroskopisch sowie 31 P-MAS-NMR-spektroskopisch (d = -11,9, -101,7 ppm) charakterisiert. Mit thermogravimetrischen Untersuchungen unter Inertgasbedingungen wurde der thermische Zersetzungspunkt ermittelt, welcher bei ca. 900 °C liegt. Die Messung der Vickers-Härte von g-P3N5 ergab einen Wert von 9,7 GPa. 7. Hexaaminodiphosphazenium-bromid, -nitrat und -toluolsulfonat. Es konnte gezeigt werden, daß die Hexaaminodiphosphazenium-Salze [(NH2)3PNP(NH2)3]Br, [(NH2)3PNP(NH2)3]NO3 und [(NH2)3PNP(NH2)3][CH3C6H4SO3] ausgehend von [(NH2)3PNP(NH2)3]Cl durch Anionenaustausch in wässriger Lösung dargestellt werden können. Die Strukturen dieser Verbindungen konnten anhand von Einkristallen, welche aus Acetonitril im Temperaturgradienten gezüchtet wurden, ermittelt werden ([(NH2)3PNP(NH2)3]Br: P 1 , a = 596,2(1)

Discoid Bicelles as Efficient Templates for Pillared Lamellar Periodic Mesoporous Silicas at pH 7 and Ultrafast Reaction Times

We report the first synthesis of periodic mesoporous silicas templated by bicelles. The obtained materials form novel pillared lamellar structures with a high degree of periodic order, narrow pore size distributions, and exceptionally high surface areas

High-Pressure Hydrogen Adsorption on a Porous Electron-Rich Covalent Organonitridic Framework

We report that a porous, electron-rich, covalent, organonitridic framework (PECONF-4) exhibits an unusually high hydrogen uptake at 77 K, relative to its specific surface area. Chahine’s rule, a widely cited heuristic for hydrogen adsorption, sets a maximum adsorptive uptake of 1 wt % hydrogen at 77 K per 500 m^2 of the adsorbent surface area. High-pressure hydrogen adsorption measurements in a Sieverts apparatus showed that PECONF-4 exceeds Chahine’s rule by 50%. The Brunauer–Emmett–Teller (BET) specific surface area of PECONF-4 was measured redundantly with nitrogen, argon, and carbon dioxide and found to be between 569 ± 2 and 676 ± 13 m^2 g^(–1). Furthermore, hydrogen on PECONF-4 has a high heat of adsorption, in excess of 9 kJ mol^(–1)

Simple Systematic Synthesis of Periodic Mesoporous Organosilica Nanoparticles with Adjustable Aspect Ratios

One-dimensional periodic mesoporous organosilica (PMO) nanoparticles with tunable aspect ratios are obtained from a chain-type molecular precursor octaethoxy-1,3,5-trisilapentane. The aspect ratio can be tuned from 2:1 to >20:1 simply by variation in the precursor concentration in acidic aqueous solutions containing constant amounts of triblock copolymer Pluronic P123. The mesochannels are highly ordered and are oriented parallel to the longitudinal axis of the PMO particles. No significant Si–C bond cleavage occurs during the synthesis according to29Si MAS NMR. The materials exhibit surface areas between 181 and 936 m2 g−1

Periodic Mesoporous Organosilica Nanorice

A periodic mesoporous organosilica (PMO) with nanorice morphology was successfully synthesized by a template assisted sol–gel method using a chain-type precursor. The PMO is composed of D and T sites in the ratio 1:2. The obtained mesoporous nanorice has a surface area of 753 m2 g−1, one-dimensional channels, and a narrow pore size distribution centered at 4.3 nm. The nanorice particles have a length of ca. 600 nm and width of ca. 200 nm

A computational framework for complex disease stratification from multiple large-scale datasets.

BACKGROUND: Multilevel data integration is becoming a major area of research in systems biology. Within this area, multi-'omics datasets on complex diseases are becoming more readily available and there is a need to set standards and good practices for integrated analysis of biological, clinical and environmental data. We present a framework to plan and generate single and multi-'omics signatures of disease states. METHODS: The framework is divided into four major steps: dataset subsetting, feature filtering, 'omics-based clustering and biomarker identification. RESULTS: We illustrate the usefulness of this framework by identifying potential patient clusters based on integrated multi-'omics signatures in a publicly available ovarian cystadenocarcinoma dataset. The analysis generated a higher number of stable and clinically relevant clusters than previously reported, and enabled the generation of predictive models of patient outcomes. CONCLUSIONS: This framework will help health researchers plan and perform multi-'omics big data analyses to generate hypotheses and make sense of their rich, diverse and ever growing datasets, to enable implementation of translational P4 medicine

Inorganic Coordination Chemistry

Inorganic Coordination Chemistry, by Kai Landskron of Lehigh University, is an extensive exploration of the chemistry of coordination compounds. This text covers topics from atomic structure and symmetry and group theory, to molecular orbitals, Lewis acid-bases and the hard and soft acid-base concept, and coordination chemistry. In addition, the book examines organometallic chemistry, complexes with metal-metal bonds, and organometallic reactions and catalysis. Inorganic Coordination Chemistry provides a comprehensive overview, and can benefit any student of inorganic chemistry

Activated Carbon Electrodes with Improved Sorption Capacity for Supercapacitive Swing Adsorption of Carbon Dioxide

Global warming due to anthropogenic CO2 emissions argues for the rapid development of efficient carbon capture technologies. Supercapacitive swing adsorption (SSA) is a gas separation technology that relies on the reversible charge and discharge of supercapacitor electrodes to adsorb and desorb CO2 highly selectively and reversibly. However, thus far SSA only showed low sorption capacity of 70 mmol/kg, and slow sorption kinetics. Herein, we show that the sorption capacity can be substantially increased via the use of carbons with a higher specific capacitance. The highest gravimetric sorption capacity was measured with electrodes made from garlic-roots derived activated carbon valuing 273 mmol.kg-1 having a specific capacitance of 257 F.g-1. In addition, the overall adsorption rate and productivity were improved. Cycling the electrodes for over 100 h showed highly reproducible, reversible CO2 adsorption and desorption behavior. A preliminary technoeconomic and sensitivity analysis is provided to demonstrate the potential of SSA for commercial applications

Scaling Supercapacitive Swing Adsorption of CO2 Using Bipolar Electrode Stacks

Supercapacitive Swing Adsorption (SSA) modules with bipolar stacks having 2, 4, 8 and 12 electrode pairs made from BPL 4x6 activated carbon were constructed and tested for carbon dioxide capture applications. Tests were performed with simulated flue gas (15%CO2 /85%N2) at 2, 4, 8 and 12 V, respectively. Reversible adsorption with sorption capacities (~58 mmol·kg-1) and adsorption rates (~38 µmol·kg-1·s-1) were measured for all stacks. The productivity scales with the number cells in the module, and increases from 70 to 390 mmol.h-1m-2. Energy efficiency and the energy consumption improved with increasing number of electrodes from 67% to 84%, and 142 to 60 kJ·mol-1, respectively. Overall, the results show that SSA modules with bipolar electrodes can be scaled without reducing the adsorptive performance, and with improvement of energetic performance

Thermodynamically Controlled High-Pressure High-Temperature Synthesis of Crystalline Fluorinated sp³‑Carbon Networks

We report the feasibility of the thermodynamically controlled synthesis of crystalline sp³-carbon networks. We show that there is a critical pressure below which decomposition of the carbon network is favored and above which the carbon network is stable. Based on advanced, highly accurate quantum mechanical calculations using the all-electron full-potential linearized augmented plane-wave method (FP-LAPW) and the Birch–Murnaghan equation of state, this critical pressure is 26.5 GPa (viz. table of contents graphic). Such pressures are experimentally readily accessible and afford thermodynamic control for suppression of decomposition reactions. The present results further suggest that a general pattern of pressure-directed control exists for many isolobal conversions of sp² to sp³ allotropes, relating not only to fluorocarbon chemistry but also extending to inorganic and solid-state materials science