Crystals

8 pages, 6979 KiB

Open AccessArticle

Structure and Magnetic Properties of Ce₃(Ni/Al/Ga)₁₁—A New Phase with the La₃Al₁₁ Structure Type

by Oliver Janka^1,2,*,†, Tian Shang^3,4,†, Ryan E. Baumbach^3,5,†, Eric D. Bauer^3,†, Joe D. Thompson^3,† and Susan M. Kauzlarich^1,*,†

¹ Department of Chemistry, University of California, Davis, CA 95616, USA

² Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität, 48149 Münster, Germany

³ Los Alamos National Laboratory, Los Alamos, NM 87545, USA

⁴ Center for Correlated Matter and Department of Physics, Zhejiang University, Hangzhou, 310027 Zhejiang, China

⁵ National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA

^† These authors contributed equally to this work.

Crystals 2015, 5(1), 1-8; https://doi.org/10.3390/cryst5010001 - 29 Dec 2014

Cited by 2 | Viewed by 7074

Abstract

Single crystals of Ce₃(Ni/Al/Ga)₁₁ were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) [...] Read more.

Single crystals of Ce₃(Ni/Al/Ga)₁₁ were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) pm. This is a standardized unit cell of the previously published La₃Al₁₁ structure type. Wavelength dispersive microprobe provides the composition of Ce_3.11(1)Ni_0.03(1)Al_8.95(1)Ga_1.90(1). Single crystal refinement provides the composition Ce₃Ni_0.08Al_9.13Ga_1.78 with substitution of the Ni and Ga on the Al1 and Al4 sites with the Al2 and Al3 solely occupied by Al. Magnetic susceptibility measurements reveal antiferromagnetic ordering with T_N = 4.8 K and there is no evidence for a ferromagnetic ordering that has been reported for Ce₃Al₁₁. The effective magnetic moment was found to be μ_eff = 1.9μ_B/Ce, which is lower than the expected value for trivalent Ce (2.54μ_B/Ce). Full article

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5 pages, 570 KiB

Open AccessCommunication

Synthesis and Molecular Structure of 2-(Diphenylphosphano)phenyl Benzoate Borane Adduct

by Constantin Mamat¹

and Martin Köckerling^2,*

¹ Institut für Radiopharmazie, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden, Germany

² Institut für Chemie, Universität Rostock, Anorganische Festkörperchemie, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany

Crystals 2015, 5(1), 9-13; https://doi.org/10.3390/cryst5010009 - 29 Dec 2014

Cited by 1 | Viewed by 6409

Abstract

The crystal and molecular structure of 2-(diphenylphosphano)phenyl benzoate borane adduct are reported. The title compound crystallizes from a petroleum ether/ethyl acetate mixture in the triclinic space group P with two molecules in the unit cell. The unit cell parameters are: a = 8.67(1) [...] Read more.

The crystal and molecular structure of 2-(diphenylphosphano)phenyl benzoate borane adduct are reported. The title compound crystallizes from a petroleum ether/ethyl acetate mixture in the triclinic space group P with two molecules in the unit cell. The unit cell parameters are: a = 8.67(1) Å, b = 9.202(1) Å, c = 14.224(2) Å; α = 72.600(7)°, β = 73.577(7)°, γ = 84.349(7)° and V = 1039.5(2) Å³. Bond lengths and angles are typical for this phosphane borane adduct. Full article

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31 pages, 6548 KiB

Open AccessArticle

Bloch Modes and Evanescent Modes of Photonic Crystals: Weak Form Solutions Based on Accurate Interface Triangulation

by Matthias Saba^1,* and Gerd E. Schröder-Turk^1,2

¹ Theoretische Physik, Friedrich-Alexander Universität Erlangen-Nürnberg, Staudtstr. 7B, 91058 Erlangen, Germany

² Applied Maths, Research School of Physical Sciences and Engineering, The Australian National University, Canberra 0200 ACT, Australia

Crystals 2015, 5(1), 14-44; https://doi.org/10.3390/cryst5010014 - 5 Jan 2015

Cited by 20 | Viewed by 10848

Abstract

We propose a new approach to calculate the complex photonic band structure, both purely dispersive and evanescent Bloch modes of a finite range, of arbitrary three-dimensional photonic crystals. Our method, based on a well-established plane wave expansion and the weak form solution of [...] Read more.

We propose a new approach to calculate the complex photonic band structure, both purely dispersive and evanescent Bloch modes of a finite range, of arbitrary three-dimensional photonic crystals. Our method, based on a well-established plane wave expansion and the weak form solution of Maxwell’s equations, computes the Fourier components of periodic structures composed of distinct homogeneous material domains from a triangulated mesh representation of the inter-material interfaces; this allows substantially more accurate representations of the geometry of complex photonic crystals than the conventional representation by a cubic voxel grid. Our method works for general two-phase composite materials, consisting of bi-anisotropic materials with tensor-valued dielectric and magnetic permittivities ε and μ and coupling matrices ς. We demonstrate for the Bragg mirror and a simple cubic crystal closely related to the Kelvin foam that relatively small numbers of Fourier components are sufficient to yield good convergence of the eigenvalues, making this method viable, despite its computational complexity. As an application, we use the single gyroid crystal to demonstrate that the consideration of both conventional and evanescent Bloch modes is necessary to predict the key features of the reflectance spectrum by analysis of the band structure, in particular for light incident along the cubic [111] direction. Full article

(This article belongs to the Special Issue Photonic Crystals)

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2 pages, 260 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Crystals in 2014

by Crystals Editorial Office

Crystals Editorial Office, MDPI AG, Klybeckstrasse 64, CH-4057 Basel, Switzerland

Crystals 2015, 5(1), 45-46; https://doi.org/10.3390/cryst5010045 - 8 Jan 2015

Viewed by 3495

Abstract

The editors of Crystals would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2014:[...] Full article

14 pages, 1107 KiB

Open AccessArticle

High-Yield Synthesis of Helical Carbon Nanofibers Using Iron Oxide Fine Powder as a Catalyst

by Yoshiyuki Suda^1,*, Koji Maruyama¹, Tetsuo Iida¹, Hirofumi Takikawa¹, Hitoshi Ue², Kazuki Shimizu³ and Yoshito Umeda⁴

¹ Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan

² Fuji Research Laboratory, Tokai Carbon Co., Ltd., Oyama, Shizuoka 410-1431, Japan

³ Development Department, Shonan Plastic Manufacturing Co., Ltd., Hiratsuka, Kanagawa 254-0807, Japan

⁴ Corporate Research Department, Toho Gas Co., Ltd., Nagoya, Aichi 456-8511, Japan

Crystals 2015, 5(1), 47-60; https://doi.org/10.3390/cryst5010047 - 8 Jan 2015

Cited by 16 | Viewed by 7521

Abstract

Carbon nanocoil (CNC), which is synthesized by a catalytic chemical vapor deposition (CCVD) method, has a coil diameter of 300–900 nm and a length of several tens of μm. Although it is very small, CNC is predicted to have a high mechanical strength [...] Read more.

Carbon nanocoil (CNC), which is synthesized by a catalytic chemical vapor deposition (CCVD) method, has a coil diameter of 300–900 nm and a length of several tens of μm. Although it is very small, CNC is predicted to have a high mechanical strength and hence is expected to have a use in nanodevices such as electromagnetic wave absorbers and field emitters. For nanodevice applications, it is necessary to synthesize CNC in high yield and purity. In this study, we improved the conditions of catalytic layer formation and CCVD. Using optimized CVD conditions, a CNC layer with a thickness of >40 μm was grown from a SnO₂/Fe₂O₃/SnO₂ catalyst on a substrate, and its purity increased to 81% ± 2%. Full article

(This article belongs to the Special Issue Carbon Nanostructures)

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13 pages, 6244 KiB

Open AccessArticle

Band Structure of Photonic Crystals Fabricated by Two-Photon Polymerization

by Mikhail V. Rybin^1,2,*, Ivan I. Shishkin^1,2, Kirill B. Samusev^1,2, Pavel A. Belov¹, Yuri S. Kivshar^1,3, Roman V. Kiyan⁴, Boris N. Chichkov⁴ and Mikhail F. Limonov^1,2

¹ ITMO University, St. Petersburg 197101, Russia

² Ioffe Physical-Technical Institute, St. Petersburg 194021, Russia

³ Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia

⁴ Laser Zentrum Hannover e.V., D-30419 Hannover, Germany

Crystals 2015, 5(1), 61-73; https://doi.org/10.3390/cryst5010061 - 13 Jan 2015

Cited by 33 | Viewed by 11735

Abstract

We study theoretically the band-gap structures of several types of three-dimensional photonic crystals with the fcc lattice symmetry: synthetic opals, inverted yablonovite and woodpile. The samples of inverted yablonovite, inverted yablonovite with a glassy superstructure and woodpile are fabricated by two-photon polymerization through [...] Read more.

We study theoretically the band-gap structures of several types of three-dimensional photonic crystals with the fcc lattice symmetry: synthetic opals, inverted yablonovite and woodpile. The samples of inverted yablonovite, inverted yablonovite with a glassy superstructure and woodpile are fabricated by two-photon polymerization through a direct laser writing technique, which allows the creation of complex three-dimensional photonic crystals with a resolution better than 100 nm. A material is polymerized along the trace of a moving laser focus, thus enabling the fabrication of any desirable three-dimensional structure by direct “recording” into the volume of a photosensitive material. The correspondence of the structures of the fabricated samples to the expected fcc lattices is confirmed by scanning electron microscopy. We discuss theoretically how the complete photonic band-gap is modified by structural and dielectric parameters. We demonstrate that the photonic properties of opal and yablonovite are opposite: the complete photonic band gap appears in the inverted opal, and direct yablonovite is absent in direct opal and inverted yablonovite. Full article

(This article belongs to the Special Issue Photonic Crystals)

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17 pages, 378 KiB

Open AccessReview

Dispersability of Carbon Nanotubes in Biopolymer-Based Fluids

by Franco Tardani and Camillo La Mesa^*

Department of Chemistry, La Sapienza University, Cannizzaro Building, P.le A. Moro 5, I-00185 Rome, Italy

Crystals 2015, 5(1), 74-90; https://doi.org/10.3390/cryst5010074 - 16 Jan 2015

Cited by 5 | Viewed by 6519

Abstract

In this review the dispersability of carbon nanotubes in aqueous solutions containing proteins, or nucleic acids, is discussed. Data reported previously are complemented by unpublished ones. In the mentioned nanotube-based systems several different phases are observed, depending on the type and concentration of [...] Read more.

In this review the dispersability of carbon nanotubes in aqueous solutions containing proteins, or nucleic acids, is discussed. Data reported previously are complemented by unpublished ones. In the mentioned nanotube-based systems several different phases are observed, depending on the type and concentration of biopolymer, as well as the amount of dispersed nanotubes. The phase behavior depends on how much biopolymers are adsorbing, and, naturally, on the molecular details of the adsorbents. Proper modulation of nanotube/biopolymer interactions helps switching between repulsive and attractive regimes. Dispersion or phase separation take place, respectively, and the formation of liquid crystalline phases or gels may prevail with respect to dispersions. We report on systems containing ss-DNA- and lysozyme-stabilized nanotubes, representative of different organization modes. In the former case, ss-DNA rolls around CNTs and ensures complete coverage. Conversely, proteins randomly and non-cooperatively adsorb onto nanotubes. The two functionalization mechanisms are significantly different. A fine-tuning of temperature, added polymer, pH, and/or ionic strength conditions induces the formation of a given supra-molecular organization mode. The biopolymer physico-chemical properties are relevant to induce the formation of different phases made of carbon nanotubes. Full article

(This article belongs to the Special Issue Carbon Nanostructures)

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9 pages, 9653 KiB

Open AccessArticle

Synthesis and Reactivity of Novel Boranes Derived from Bulky Salicylaldimines: The Molecular Structure of a Maltolato Compound

by Jeremy L. Bourque¹, Stephen J. Geier¹, Christopher M. Vogels¹, Andreas Decken² and Stephen A. Westcott^1,*

¹ Department of Chemistry and Biochemistry, Mount Allison University, Sackville NB E4L 1G8, Canada

² Department of Chemistry, University of New Brunswick, Fredericton NB E3B 5A3, Canada

Crystals 2015, 5(1), 91-99; https://doi.org/10.3390/cryst5010091 - 5 Feb 2015

Cited by 1 | Viewed by 5571

Abstract

Reductive amination of salicylaldehyde or 3,5-di-tert-butylsalicylaldehyde and 1-adamantylamine using NaBH₄ gave the corresponding aminoalcohols in high yields. Subsequent addition of one equivalent of H₃B·SMe₂ to the aminoalcohols, with loss of two equivalents of dihydrogen, resulted in the [...] Read more.

Reductive amination of salicylaldehyde or 3,5-di-tert-butylsalicylaldehyde and 1-adamantylamine using NaBH₄ gave the corresponding aminoalcohols in high yields. Subsequent addition of one equivalent of H₃B·SMe₂ to the aminoalcohols, with loss of two equivalents of dihydrogen, resulted in the formation of adamantanyl oxazaborinanes (1a,b). The molecular structure of 1b was studied by a single crystal X-ray diffraction study. Crystals were obtained from a saturated Et₂O solution and belong to the triclinic space group Pī with unit cell parameters a = 9.1267(4) Å; b = 11.676(2) Å; c = 12.240(3) Å; α = 66.840(3)°; β = 78.529(3)°; and γ = 67.354(3)°. The molecular structure of the addition product (2a) arising from maltol and 1a was also confirmed by single crystal X-ray diffraction. Crystals were obtained from a saturated 1:2 mixture of toluene/Et₂O and belong to the orthorhombic space group Pna2(1) with unit cell parameters a = 18.519(6) Å; b = 17.315(5) Å; and c = 12.680(4) Å. The asymmetric unit contains two molecules that differ slightly in some of the dihedral angles. Full article

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16 pages, 20350 KiB

Open AccessArticle

Synthesis, Crystal and Molecular Structure Studies and DFT Calculations of Phenyl Quinoline-2-Carboxylate and 2-Methoxyphenyl Quinoline-2-Carboxylate; Two New Quinoline-2 Carboxylic Derivatives

by Edakot Fazal¹, Jerry P. Jasinski^2,*, Brian J. Anderson², Manpreet Kaur³, Subban Nagarajan⁴ and Belgur Satyanarayana Sudha¹

¹ Department of Chemistry, Yuvarajaʼs College, University of Mysore, Mysore-570 005, India

² Department of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA

³ Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India

⁴ Spice and Flavor Science Department, CSIR-Central Food Technological Research institute, Mysore 570005, India

Crystals 2015, 5(1), 100-115; https://doi.org/10.3390/cryst5010100 - 12 Feb 2015

Cited by 7 | Viewed by 7118

Abstract

The crystal and molecular structures of the title compounds, phenyl quinoline-2-carboxylate and 2-methoxyphenyl quinoline-2-carboxylate, two new derivatives of quinolone-2-carboxylic acid, are reported and confirmed by single crystal X-ray diffraction and spectroscopic data. Compound (I), C₁₆H₁₁NO₂, [...] Read more.

The crystal and molecular structures of the title compounds, phenyl quinoline-2-carboxylate and 2-methoxyphenyl quinoline-2-carboxylate, two new derivatives of quinolone-2-carboxylic acid, are reported and confirmed by single crystal X-ray diffraction and spectroscopic data. Compound (I), C₁₆H₁₁NO₂, crystallizes in the monoclinic space group P2₁/c, with 8 molecules in the unit cell. The unit cell parameters are a = 14.7910(3) Å; b = 5.76446(12) Å; c = 28.4012(6) Å; β = 99.043(2)°; V = 2391.45(9) Å³. Compound (II), C₁₇H₁₃NO₅, crystallizes in the monoclinic space group P2₁/n with 4 molecules in the unit cell. The unit cell parameters are a = 9.6095(3) Å; b = 10.8040(3) Å; c = 13.2427(4) Å; β = 102.012(3)°; V = 1344.76(7) Å³. Density functional theory (DFT) geometry optimized molecular orbital calculations were performed and frontier molecular orbitals of each compound are displayed. Correlation between the calculated molecular orbital energies (eV) for the surfaces of the frontier molecular orbitals to the electronic excitation transitions from the absorption spectra of each compound has been proposed. Additionally, similar correlations observed among six closely related compounds examining small structural differences to their frontier molecular orbital surfaces and from their DFT molecular orbital energies, provide further support for the suggested assignments of the title compounds. Full article

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27 pages, 30112 KiB

Open AccessArticle

Controlled Deposition of Tin Oxide and Silver Nanoparticles Using Microcontact Printing

by Joo C. Chan¹, Nicole Hannah-Moore² and Shankar B. Rananavare^2,*

¹ Intel D1C Lithography Engineering, Intel Corporation, Ronler Acres, Hillsboro, OR 97124, USA

² Department of Chemistry, Portland State University, Portland, OR 97207, USA

Crystals 2015, 5(1), 116-142; https://doi.org/10.3390/cryst5010116 - 13 Feb 2015

Cited by 6 | Viewed by 9889

Abstract

This report describes extensive studies of deposition processes involving tin oxide (SnO_x) nanoparticles on smooth glass surfaces. We demonstrate the use of smooth films of these nanoparticles as a platform for spatially-selective electroless deposition of silver by soft lithographic stamping. The [...] Read more.

This report describes extensive studies of deposition processes involving tin oxide (SnO_x) nanoparticles on smooth glass surfaces. We demonstrate the use of smooth films of these nanoparticles as a platform for spatially-selective electroless deposition of silver by soft lithographic stamping. The edge and height roughness of the depositing metallic films are 100 nm and 20 nm, respectively, controlled by the intrinsic size of the nanoparticles. Mixtures of alcohols as capping agents provide further control over the size and shape of nanoparticles clusters. The distribution of cluster heights obtained by atomic force microscopy (AFM) is modeled through a modified heterogeneous nucleation theory as well as Oswald ripening. The thermodynamic modeling of the wetting properties of nanoparticles aggregates provides insight into their mechanism of formation and how their properties might be further exploited in wide-ranging applications. Full article

(This article belongs to the Special Issue Nanostructured Oxide Crystals)

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11 pages, 726 KiB

Open AccessArticle

TEV—A Program for the Determination of the Thermal Expansion Tensor from Diffraction Data

by Thomas Langreiter and Volker Kahlenberg^*

Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, A-6020 Innsbruck, Austria

Crystals 2015, 5(1), 143-153; https://doi.org/10.3390/cryst5010143 - 16 Feb 2015

Cited by 70 | Viewed by 8679

Abstract

TEV (Thermal Expansion Visualizing) is a user-friendly program for the calculation of the thermal expansion tensor α_ij from diffraction data. Unit cell parameters determined from temperature dependent data collections can be provided as input. An intuitive graphical user interface enables fitting of [...] Read more.

TEV (Thermal Expansion Visualizing) is a user-friendly program for the calculation of the thermal expansion tensor α_ij from diffraction data. Unit cell parameters determined from temperature dependent data collections can be provided as input. An intuitive graphical user interface enables fitting of the evolution of individual lattice parameters to polynomials up to fifth order. Alternatively, polynomial representations obtained from other fitting programs or from the literature can be entered. The polynomials and their derivatives are employed for the calculation of the tensor components of α_ij in the infinitesimal limit. The tensor components, eigenvalues, eigenvectors and their angles with the crystallographic axes can be evaluated for individual temperatures or for temperature ranges. Values of the tensor in directions parallel to either [uvw]’s of the crystal lattice or vectors (hkl) of reciprocal space can be calculated. Finally, the 3-D representation surface for the second rank tensor and pre- or user-defined 2-D sections can be plotted and saved in a bitmap format. TEV is written in JAVA. The distribution contains an EXE-file for Windows users and a system independent JAR-file for running the software under Linux and Mac OS X. The program can be downloaded from the following link: http://www.uibk.ac.at/mineralogie/downloads/TEV.html (Institute of Mineralogy and Petrography, University of Innsbruck, Innsbruck, Austria) Full article

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9 pages, 6904 KiB

Open AccessReview

Let’s Talk about MOFs—Topology and Terminology of Metal-Organic Frameworks and Why We Need Them

by Lars Öhrström

Institutionen för Kemi-och Kemiteknik, Chalmers Tekniska Högskola, SE-412 96 Gothenburg, Sweden

Crystals 2015, 5(1), 154-162; https://doi.org/10.3390/cryst5010154 - 16 Feb 2015

Cited by 71 | Viewed by 13769

Abstract

Recent IUPAC (The International Union for Pure and Applied Chemistry) recommendations on the terminology of metal-organic frameworks are reviewed and the background to a proposed topology classification is discussed. The various numerical designators such as point symbols, vertex symbols and transitivity are also [...] Read more.

Recent IUPAC (The International Union for Pure and Applied Chemistry) recommendations on the terminology of metal-organic frameworks are reviewed and the background to a proposed topology classification is discussed. The various numerical designators such as point symbols, vertex symbols and transitivity are also explained and their importance elucidated. Full article

(This article belongs to the Special Issue Metal-Organic Frameworks (MOFs): Energy and Informatics)

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Crystals, Volume 5, Issue 1 (March 2015) – 13 articles , Pages 1-171

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