<p>Materials with new or improved properties are crucial for technological development. To provide the foundation for future successful products, it is important to prepare and characterise new chemical compounds that could show unusual properties. The properties of magnetic materials are closely related to their crystal, magnetic and electronic structures. This thesis focuses on the novel synthesis and structural characterisation of a number of new ternary or <i>pseudo</i>-ternary silicides and germanides of manganese with iridium, cobalt or palladium. To provide a more complete picture of the complex magnetic properties, crystal and magnetic structure refinements by the Rietveld method of X-ray and neutron powder diffraction data are complemented by single-crystal X-ray diffraction, electron diffraction, magnetisation measurements and Reverse Monte Carlo simulations of magnetic short-range order. The experimental results are corroborated by first-principles electronic structure and total energy calculations. </p><p>A commensurate non-collinear antiferromagnetic structure is found for most compounds of the solid solution Mn₃Ir_1-yCo_ySi_1-xGe_x. The non-collinearity is a result of geometric frustration in a crystal structure with magnetic Mn atoms located on a three-dimensional network of triangles. The close structural similarity to the β-modification of elemental manganese, which does not order magnetically, inspired a closer theoretical comparison of the Mn₃Ir_1-yCo_ySi_1-xGe_x propertieswith β-Mn.</p><p>Magnetic frustration is also observed for Mn₄Ir_7-xMn_xGe₆, and is an important factor underlying the dramatic change from commensurate antiferromagnetic order to spin glass properties induced by a small variation in Mn concentration. Magnetic short-range order with dominant antiferromagnetic correlation is observed for Mn₈Pd₁₅Si₇, and results from a random distribution of Mn atoms in-between the geometrically frustrated magnetic moments on the Mn octahedra. </p><p>An incommensurate cycloidal magnetic structure, observed for IrMnSi, is stabilised by an electronic structure effect, which also accounts for the non-collinearity of the Mn₃IrSi type magnetic structure.</p>

<p>The parasite <i>Echinococcus granulosus</i> causes hydatid disease, a major zoonosis. A fatty-acid-binding protein, EgFABP1, is important for the parasite, as it must acquire almost all its lipids from its environment or the host. The structure of EgFABP1 has been solved and refined to 1.6 Å resolution. The structure reveals that EgFABP1 has the 10-stranded β-barrel fold typical of the family of intracellular lipid-binding proteins. </p><p>Human semicarbazide-sensitive amine oxidase (SSAO; EC 1.4.3.6), also known as vascular adhesion protein-1, is a copper-containing monoamine oxidase that occurs both as a membrane-bound protein and in a soluble form in plasma. SSAO has been implicated in glucose transport in adipocytes, the differentiation of adipose cells and the leukocyte extravasation process. Toxic reaction products have been suggested to cause some of the vascular complications associated with diabetes and SSAO is therefore of pharmaceutical interest.</p><p>The structure of a truncated, soluble form of human SSAO has been determined to 2.5 Å resolution. The structure reveals that a leucine residue located adjacent to the active site could function as a gate controlling its accessibility. An RGD motif is displayed on the surface where it could be involved in integrin binding and possibly play a role in the shedding of SSAO from the membrane. Carbohydrate moieties are observed at five out of six potential N-glycosylation sites. Carbohydrates attached to Asn 232 flank the active site entrance and might influence substrate specificity. The structure also reveals a vicinal disulfide bridge, which we hypothesise could act as a redox switch involved in the protein’s mechanism of action. The structure of a complex of SSAO and the irreversible inhibitor 2-hydrazinopyridine has been solved and refined to 2.9 Å resolution. Both structures together will aid efforts to identify natural substrates, provide valuable information for the design of specific inhibitors and direct further studies. </p>

Die Suche nach neuen Materialien von technischem Interesse hat in den letzten Jahren neue Antriebe zu der Untersuchung organischer Verbindungen gegeben. Organische Substanzen haben viele Vorteile wie z.B. die Möglichkeit, ihre Eigenschaften durch verschiedene chemische und physikalische Techniken im Herstellung-Prozess für ein bestimmtes Ziel zu modifizieren. Oxadiazolverbindungen sind interessant aufgrund ihrer Nutzung als Material für Licht emittierende Dioden und Scintillatoren. <br /> <br /> Die physikalischen Eigenschaften eines Festkörpers hängen von seiner Struktur ab. Unterschiedliche Strukturen entwickeln unterschiedliche intra- und intermolekülare Wechselwirkungen. Eine ausgezeichnete Weise, um sowohl die intra- als auch die intermolekularen Wechselwirkungen eines bestimmtes Stoffes zu beeinflussen, ohne seine chemischen Charakteristiken zu ändern, ist die Verwendung von hohem Druck. <br /> <br /> Wir haben den Einfluss von hohem Druck und hoher Temperatur auf die super-molekulare Struktur einiger Oxadiazolverbindungen im kristallinem Zustand untersucht. Aus diesen Untersuchungsergebnissen wurde eine Zustandsgleichung für diese Kristalle bestimmt. Überdies wurden die spektroskopischen Eigenschaften dieser Materialien unter hohem Druck charakterisiert. / In recent years the search for new materials of technological interest has given new impulses to the study of organic compounds. Organic substances possess a great number of advantages such as the possibility to adjust their properties for a given purpose by different chemical and physical techniques in the preparation process. Oxadiazole derivatives are interesting due to their use as material for light emitting diodes (LED) as well as scintillators. <br /> <br /> The physical properties of a solid depend on its structure. Different structures induce different intra- and intermolecular interactions. An advantageous method to modify the intra- as well as the intermolecular interactions of a given substance is the application of high pressure. Furthermore, using this method the chemical features of the compound are not influenced.<br /> <br /> We have investigated the influence of high pressure and high temperature on the super-molecular structure of several oxadiazole derivatives in crystalline state. From the results of this investigation an equation of state for these crystals was determined. Furthermore, the spectroscopical features of these materials under high pressure were characterized.

Cellulosabaserade material är världens rikligast förekommande förnyelsebara råvara. Växters cellväggar är naturliga kompositmaterial där den kristallina cellulosan är inbäddad i en väv av hemicellulosa, strukturproteiner och lignin. Xyloglukaner är en viktig hemicellulosagrupp som omger och korslänkar den kristallina cellulosan i cellväggarna. I denna avhandling undersöks undersöks sambanden mellan struktur och funktion hos olika xyloglukan-aktiva enzymer. En modell för effektiv enzymatisk omvandling av biomassa ges av cellulosomen hos den anaeroba prokaryota organismen Clostridium thermocellum. Cellulosomen är ett proteinkomplex med hög molmassa och flera olika enzymaktiviteter, bl.a. det inverterande xyloglukan-endohydrolaset CtXGH74A. Proteinstrukturen för CtXGH74A har lösts i komplex med xyloglukanoligosackarider, som stabliliserar vissa loopar/slingor som är oordnade i apostrukturen. Ytterligare detaljerade kinetiska och produktananalyser har genomförts för att entydigt visa att CtXGH74A är ett endoxyloglukanas vars slutliga nedbrytningsprodukt är Glc4-baserade xyloglukanoligosackarider. Som jämförelse innehåller glykosidhydrolasfamilj 16 (GH16) såväl hydrolytiska endoxyloglukanaser som xyloglukantransglykosylaser (XETs) från växter. För att utreda vad som bestämmer förhållandet mellan transglykosylering och hydrolys i xyloglukanaktiva enzymer från familj GH 16 jämfördes struktur och kinetik hos ett strikt transglykosylas, PttXET16-34 från hybridasp, med ett nära besläktat hydrolytiskt enzym, NXG1 från krasse. I NXG1 identifierades en viktig förlängningsloop, som vid trunkering gav ett muterat enzym med högre transglykosyleringshastighet och minskad hydrolytisk aktivitet. Kinetikstudierna genomfördes med hjälp av nyutvecklade känsliga provmetoder med väldefinerade XGO:er och ett antal kromogena XGO-arylglykosider. En detaljerad förståelse av enzymologin inom GH16 möjliggjorde utvecklingen av en ny kemoenzymatisk metod för biomimetisk fiberytmodifiering med hjälp av PttXET16-34s translgykosyleringsaktivitet. Aminoalditolderivat av xyloglukanoligosackarider användes som nyckelintermediärer för att introducera ny kemisk funktionalitet hos xyloglukan, såsom kromoforer, reaktiva grupper, proteinligander och initiatorer för polymeriseringsreaktioner. Tekniken innebär ett nytt och mångsidigt verktyg för fiberytmodifiering. / Zellulosehaltige Materialien sind die häufigsten erneuerbaren Rohmaterialien auf der Welt. Pflanzenzellwände sind natürliche Kompositmaterialien, sie enthalten kristalline Zellulose, die in einer Matrix aus Hemizellulosen, Proteinen und Lignin eingebettet sind. Xyloglukane sind eine wichtige Gruppe der Hemizellulosen, sie ummanteln und verbinden Zellulose in der pflanzlichen Zellwand. In dieser Abhandlung werden Strukturen von drei Xyloglukanaktiven Enzymen in Beziehung zu ihrer Funktion untersucht. Ein Paradigma für effizienter Nutzung von Biomasse ist das Cellulosom des anaerob lebenden Bakteriums Clostridium thermocellum. Das Cellulosom ist ein hochmolekularer Komplex von Proteinen mit vielen verschiedenen Aktivitäten, darunter ist auch die invertierende Xyloglukan Endohydrolase CtXGH74A. Die Proteinstruktur von CtXGH74A wurde im Komplex mit Xyloglukanoligosacchariden (XGO) gelöst, welche ungeordnete Loops der apo-Struktur stabilisierten. Durch weitere detaillierte Analyse der Kinetik und Reaktionsprodukte konnte schlüssig gezeigt werden, daß CtXGH74A eine Endoglukanase ist, die Glc4-basierte XGO produziert. Im Vergleich dazu enthält die retentierende Glykosidhydrolasefamilie 16 (GH16) sowohl hydrolytische Endoxyloglukanasen als auch Transglykosidasen von Pflanzen. Um zu erklären welche Faktoren das Verhältnis zwischen Transglykosidase und Hydrolase Aktivität bei GH16 Xyloglukanaktiven Enzymen bestimmen wurde eine reine Transglykosidase PttXET16-34 von Hybridaspen mit einem nah verwandten hydrolytischen Enzym NXG1 von Kapuzinerkresse strukturell und kinetisch verglichen. Als Schlüsselstelle wurde eine Verlängerung eines Loops in NXG1 identifiziert, Verkürzung des Loops führte zu einer Mutante mit erhöhter Transglykosylierungsrate bei verminderter hydrolytischer Aktivität. Kinetische Studien wurden erleichtert durch neu entwickelte hochempfindliche Methoden für Aktivitätsmessung, die auf XGO oder chromogene Aryl-XGO als definierte Substrate zurückgreifen. Detailliertes Verständnis von GH16 Enzymologie hat den Weg für die Entwicklung für eine neuartige Methode für biomimetische Oberflächenmodifikation von Zellulosefibern geebnet, dafür wurde die transglykosylierende Aktivität von PttXET16-34 angewendet. Aminoalditol-derivate von XGO wurden als wichtigste Zwischenprodukte angewendet, um neue chemische Funktionalitäten in Xyloglukan einzuführen, darunter waren Chromophore, reaktive Gruppen, Proteinliganden und Initiatoren für Polymerisationsreaktionen. Die modifizierten Xyloglukane wurden an eine Reihe von verschiedenen Zellulosematerialien gebunden und veränderten die Oberflächeneigenschaften dramatisch. Diese Methode ist ein neues wertvolles Werkzeug für Oberflächenmodifikation von Zellulosen. / Cellulosic materials are the most abundant renewable resource in the world; plant cell walls are natural composite materials containing crystalline cellulose embedded in a matrix of hemicelluloses, structural proteins, and lignin. Xyloglucans are an important group of hemicelluloses, which coat and cross-link crystalline cellulose in the plant cell wall. In this thesis, structure-function relationships of a range of xyloglucan-active enzymes were examined. A paradigm for efficient enzymatic biomass utilization is the cellulosome of the anaerobic bacterium Clostridium thermocellum. The cellulosome is a high molecular weight complex of proteins with diverse enzyme activities, including the inverting xyloglucan endo-hydrolase CtXGH74A. The protein structure of CtXGH74A was solved in complex with xyloglucan oligosaccharides (XGOs) which stabilized disordered loops of the apo-structure. Further detailed kinetic and product analyses were used to conclusively demonstrate that CtXGH74A is an endo-xyloglucase that produces Glc4-based XGOs as limit digestion products. In comparison, the retaining glycoside hydrolase family 16 (GH16) contains hydrolytic endo-xyloglucanases as well as xyloglucan transglycosylases (XETs) from plants. To elucidate the determinants of the transglycosylase/hydrolysis ratio in GH16 xyloglucan-active enzymes, a strict transglycosylase, PttXET16-34 from hybrid aspen, was compared structurally and kinetically with the closely related hydrolytic enzyme NXG1 from nasturtium. A key loop extension was identified in NXG1, truncation of which yielded a mutant enzyme that exhibited an increased transglycosylase rate and reduced hydrolytic activity. Kinetic studies were facilitated by the development of new, sensitive assays using well-defined XGOs and a series of chromogenic XGO aryl-glycosides. A detailed understanding of GH16 xyloglucan enzymology has paved the way for the development of a novel chemo-enzymatic approach for biomimetic fiber surface modification, in which the transglycosylating activity of PttXET16-34 was employed. Aminoalditol derivates of XGOs were used as key intermediates to incorporate novel chemical functionality into xyloglucan, including chromophores, reactive groups, protein ligands, and initiators for polymerization reactions. The resulting modified xyloglucans were subsequently bound to a range of cellulose materials to radically alter surface properties. As such, the technology provides a novel, versatile toolkit for fiber surface modification. / QC 20100624

The parasite Echinococcus granulosus causes hydatid disease, a major zoonosis. A fatty-acid-binding protein, EgFABP1, is important for the parasite, as it must acquire almost all its lipids from its environment or the host. The structure of EgFABP1 has been solved and refined to 1.6 Å resolution. The structure reveals that EgFABP1 has the 10-stranded β-barrel fold typical of the family of intracellular lipid-binding proteins. Human semicarbazide-sensitive amine oxidase (SSAO; EC 1.4.3.6), also known as vascular adhesion protein-1, is a copper-containing monoamine oxidase that occurs both as a membrane-bound protein and in a soluble form in plasma. SSAO has been implicated in glucose transport in adipocytes, the differentiation of adipose cells and the leukocyte extravasation process. Toxic reaction products have been suggested to cause some of the vascular complications associated with diabetes and SSAO is therefore of pharmaceutical interest. The structure of a truncated, soluble form of human SSAO has been determined to 2.5 Å resolution. The structure reveals that a leucine residue located adjacent to the active site could function as a gate controlling its accessibility. An RGD motif is displayed on the surface where it could be involved in integrin binding and possibly play a role in the shedding of SSAO from the membrane. Carbohydrate moieties are observed at five out of six potential N-glycosylation sites. Carbohydrates attached to Asn 232 flank the active site entrance and might influence substrate specificity. The structure also reveals a vicinal disulfide bridge, which we hypothesise could act as a redox switch involved in the protein’s mechanism of action. The structure of a complex of SSAO and the irreversible inhibitor 2-hydrazinopyridine has been solved and refined to 2.9 Å resolution. Both structures together will aid efforts to identify natural substrates, provide valuable information for the design of specific inhibitors and direct further studies.

Materials with new or improved properties are crucial for technological development. To provide the foundation for future successful products, it is important to prepare and characterise new chemical compounds that could show unusual properties. The properties of magnetic materials are closely related to their crystal, magnetic and electronic structures. This thesis focuses on the novel synthesis and structural characterisation of a number of new ternary or pseudo-ternary silicides and germanides of manganese with iridium, cobalt or palladium. To provide a more complete picture of the complex magnetic properties, crystal and magnetic structure refinements by the Rietveld method of X-ray and neutron powder diffraction data are complemented by single-crystal X-ray diffraction, electron diffraction, magnetisation measurements and Reverse Monte Carlo simulations of magnetic short-range order. The experimental results are corroborated by first-principles electronic structure and total energy calculations. A commensurate non-collinear antiferromagnetic structure is found for most compounds of the solid solution Mn3Ir1-yCoySi1-xGex. The non-collinearity is a result of geometric frustration in a crystal structure with magnetic Mn atoms located on a three-dimensional network of triangles. The close structural similarity to the β-modification of elemental manganese, which does not order magnetically, inspired a closer theoretical comparison of the Mn3Ir1-yCoySi1-xGex propertieswith β-Mn. Magnetic frustration is also observed for Mn4Ir7-xMnxGe6, and is an important factor underlying the dramatic change from commensurate antiferromagnetic order to spin glass properties induced by a small variation in Mn concentration. Magnetic short-range order with dominant antiferromagnetic correlation is observed for Mn8Pd15Si7, and results from a random distribution of Mn atoms in-between the geometrically frustrated magnetic moments on the Mn octahedra. An incommensurate cycloidal magnetic structure, observed for IrMnSi, is stabilised by an electronic structure effect, which also accounts for the non-collinearity of the Mn3IrSi type magnetic structure.

Nonlinear optics and ferroelectrics have been recognized for several decades as promising fields with important applications in the area of opto-electronics, photonics, memory devices, etc. High performance electro-optical switching elements for telecommunications and optical information processing are based on the material properties. Hence, there is always a continuous search for new and better materials. In this thesis we have investigated the growth and physical properties of four crystals viz. two NLO and two ferroelectric crystals. This thesis consists of eight chapters. The first chapter gives an overview of historical perspectives of nonlinear optical phenomenon, ferroelectricity and materials developed therein. The second chapter gives a brief description of the underlying theories of crystal growth, nonlinear optics and ferroelectricity. A major portion of this chapter consists of gist of the earlier work carried out on compounds of our interest viz. urea L-malic acid, sodium p-nitrophenolate dihydrate, glycine phosphite and lithium niobate. Synthesis, growth, crystal structure details and some physical properties of these materials are briefed. The third chapter describes the experimental techniques needed to grow as well as characterize these crystals. The experiments are performed on single crystals grown in the laboratory using the solution growth setup and Czochralski crystal puller. These growth units are described in detail. Preliminary characterization techniques like powder Xray diffraction, optical transmission, scanning electron microscopy, Vickers and Knoop hardness are described briefly. Various experimental methods viz. dielectric, polarization reversal, photoacoustic spectroscopy and laser induced damage for characterizing the grown crystals are explained. Urea L-malic acid (ULMA) is a new NLO organic material which is reported to exhibit second harmonic efficiency three times that of the widely used inorganic crystal, KDP. Hence, this material is selected for detailed investigation and the results obtained are discussed in chapter 4. This chapter contains details of single crystal growth and characterization of ULMA. The crystals are grown by slow cooling technique. The complete morphology of the crystal is evaluated using optical goniometry. The grown crystals are characterized for their optical and thermal properties. The defect content in the grown crystal is evaluated by chemical etching. As the surface damage of the crystal by high power lasers limits its performance in NLO applications, a detailed laser induced damage studies are performed on ULMA. Both single shot and multiple shot damage threshold values for 1064 nm and 532 nm laser radiation are determined and correlated with the mechanical hardness. In addition, the thermal diffusivity and thermal conductivity of ULMA along various crystallographic orientations are evaluated using laser induced photoacoustic spectroscopy and the results are interpreted in terms of crystal bonding environment. Another NLO crystal taken up for study is sodium p-nitrophenolate dihydrate (NPNa 2H2O), a semiorganic material. This crystal is a very efficient NLO material and has the advantages of both organics and inorganics. Earlier investigations on growth of NPNa.2H2O in various solvents have shown methanol as the most suitable solvent for growth. Growth from aqueous solution was discarded as it did not yield crystals which are stable. In the present investigation, stable, NLO active NPNa.2H2O crystals are obtained using aqueous solution itself by varying the crystallization conditions and exploring the suitable temperature range. The details of growth and characterization form the subject of fifth chapter. The grown crystals are characterized using optical transmission, XRD and thermo gravimetric analysis. Later, laser induced damage threshold is evaluated for both 1064 nm and 532 nm laser radiation and compared wit the methanol grown ones. A possible mechanism of damage is given. The sixth and seventh chapters deal with growth and characterization of ferroelectric materials namely glycine phosphite and lithium niobate respectively. Glycine phosphite is a low temperature ferroelectric crystal which is well studied in terms of its dielectric and ferroelectric properties. But very few radiation damage studies are reported. The effect of ionizing radiation on ferroelectrics is of considerable interest as it significantly modifies the physical properties of these materials. In the present investigation, effects of X-ray irradiation (_ = 1.5418 °A) on the lattice parameters, dielectric constant, loss tangent, polarization switching characteristics and domain dynamics of glycine phosphite are investigated. X-ray irradiation is performed in the non-polar phase of the sample. The effect as a function of duration of exposure is studied. X-ray irradiation in GPI has resulted in drastic reduction in _ values and shift in transition temperature towards lower temperatures. X-ray irradiation on polarization switching properties of the crystal are also investigated. The activation energy and threshold field of switching increase with the irradiation time. The behaviour of domain wall mobility is quite different from that exhibited by other well known ferroelectrics. These results are discussed in chapter 6 and a possible explanation for the unusual behaviour of domain wall mobility is given. The defect generated is identified as PO32− radical by electron paramagnetic measurement. Lithium niobate (LiNbO3) is an extensively studied material in terms of its NLO and ferroelectric properties. This material has high piezoelectric coupling coefficients along certain directions which makes it suitable for wide band surface acoustic wave applications. Hence there is a demand for good quality, single domain YZ-LiNbO3 substrates. Chapter 7 describes the growth of Z-pulled congruent LiNbO3 using Czochralski technique. Large single crystals of diameter 30 mm and length 80 mm are grown from congruent composition employing Czochralski technique. The grown crystals are multidomain and hence electric field poling is performed to get single domain crystals. Their subsequent characterization for SAW devices upto 200 MHz was performed and compared with the imported substrate. The general conclusions are given in chapter 8 along with possible future work that could be performed on these crystals.

ΔPhe an analogue of a coded amino acid phenylalanine (Phe) residue but with double bond between Cα and Cβ atoms, is one of the well studied residue among all the dehydro amino acids, as a conformation constraining amino acid. Due to the presence of double bond Cα=Cβ, and consequent conjugation of ΔPhe ring electrons with Cα=Cβ double bond, ΔPhe gains conformation restricting (constraining) characteristics compared to coded amino acid Phe. ΔPhe which assumes an achiral residue has all its atoms restricted to an approximate plane. Apart from the conformation constraining property, the designer friendly ΔPhe residue has its ability to i) engage in side chain aromatic interactions ii) act as nuclei for C-HLO/N-HLπ weak interactions involving the side chain and/ or backbone atoms, and iii) acquire ambidextrous conformation as observed in many model peptides. It is these properties, which makes ΔPhe, a residue of intense research in the field of de novo protein secondary and super secondary design. Analysis of solid state and solution state structures of containing ΔPhe residues suggests that ΔPhe, in general induces β-bend in short peptides and 310-helical conformation in longer peptides (>4).

The new borophosphates described here were synthesized under mild hydrothermal conditions (170 oC or 220 oC). Powder and single crystal X-ray diffraction were employed to determine and refine the crystal structures. DTA-TG methods were used to analyze the thermal stability. High temperature powder X-ray diffraction (HT-XRD) was applied to study the thermal behavior of products and identify the intermediate phase during the decomposition. Chemical analyses were performed to quantitatively determine the chemical composition. Magnetic properties of the compounds were investigated. 19F MAS NMR was used to check the number of fluorine positions in the crystal structure. The following compounds were prepared and characterized: (C2H10N2)[BPO4F2](C6H14N2){Zn[ZnB2P4O15(OH)2]¡P(C6H13N2)Cl} (zndabcocl) (C3H12N2){Mn[B2P3O12(OH)]} (DAP-Mn) and (C4H12N2){Mn[B2P3O12(OH)]} (PIP-Mn) (C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]}(C3H12N2)2{VIII2VIV3B2P8O38H8} (dapvbpo) K3[B5PO10(OH)3](C2H10N2)[BPO4F2] is the first fluorine-substituted borophosphate and the first borophosphate with crystal structure closely related to the pyroxene type structure. Unbranched zweier single chain {[BPO4F2]2?} represents a new type of borophosphate partial structure. zndabcoclrepresents the first organo-templated zincoborophosphate. The structure contains diaza-bicyclo[2.2.2]-octane (DABCO) which acts in its diprotonated form (H2DABCO)2+ as a pure template and in its monoprotonated form (HDABCO)+ as a ligand to Zn-positions at the borders of ribbons to complete structural motif. This compound is also the first example containing a quaternary Zn-tetrahedron (ZnO2NCl), and can formally be described as an adduct of (C6H14N2)Zn[ZnB2P4O15(OH)2] with diaza-bicyclo[2.2.2]octane-hydrochloride. The thermal behavior of zndabcocl has been studied by HT-XRD and DTA-TG in the temperature range 25?600 oC. The new phase occurring during the decomposition has been identified as HT-NH4[ZnBP2O8].DAP-Mnand PIP-Mn contain identical framework interconnections but difference in the shape of resulting channels, which are due to the different shape of organic templates. The crystal structures are built from the same building units: loop-branched single chains are connected via MnO6-octahedra resulting in a 3-D structure with intersecting channel systems running along [100], [011] and [01], respectively. The different shape of the template controls the shape of the channels, especially channels running along [100], resulting in dramatic shape-differences. The linear (H2DAP)2+ ions make the channels more elongated, while the cyclic (H2PIP)2+ ions give rise to more regular shaped channels. The flexibility of frameworks may be due to the more flexible coordination of Mn-atoms (octahedron and square pyramid).(C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]} is a new borophosphate with 3-D framework structure, a large size of 10-ring channel (778 ¡Ñ 867 pm2) is occupied by organic templates. The magnetic susceptibility measurements show it to exhibit antiferromagnetic susceptibility at low temperature (TN ?l 14K).dapvbpois the first mixed-valency vanadium borophosphate with a new structure type. Its structure can be considered as an ?intergrowth? of puckered vanadium(III) borophosphate layer (VIIIBPO-layer) and planar vanadium(IV) phosphate layers (VIVPO-layer) stacked and interconnected alternately along [001], which results in a new and unusual building motif. The corner sharing trimers of vanadium octahedra are observed for the first time in vanadium borophosphates. K3[B5PO10(OH)3] has a double unit cell of a twin crystal structure having the same chemical formula. The double b-axis solves the disorder problem of two oxygen positions coordinated to phosphorous. It represents a much more reasonable structure determination.

No description available.