Author Archive

Orientation of halogen bonds has key role in controlling crystal packing

Orientation of halogen bonds has key role in controlling crystal packingBy looking at the structures of halogen-bonded infinite chains with two diiodoperfluoroalkanes and a bent bis(pyrid-4′-yl)oxadiazole, Giuseppe Resnati and colleagues have investigated the influence that halogen bond directionality has on supramolecular design.  The bent geometry of the pyridyl pendant rings in the structures were found to translate into the angle between the formed halogen bonds, taking precedence over parameters that might affect the crystal packing.

Download their HOT CrystEngComm communication today to find out more…

Halogen bond directionality translates tecton geometry into self-assembled architecture geometry
Marco Saccone, Gabriella Cavallo, Pierangelo Metrangolo, Andrea Pace, Ivana Pibiri, Tullio Pilati, Giuseppe Resnati and Giancarlo Terraneo
CrystEngComm, 2013
DOI: 10.1039/C3CE40268A, Communication

This communication is part of a themed issue on Halogen bonding (guest edited by Giuseppe Resnati, Mark Taylor and William Pennington) which is due to go online next week.

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Modelling metastable zone width

Modelling metastable zone widthNoriaki Kubota and colleagues have modelled the effects of sensitivity and resolution of a nucleation detector on metastable zone width. 

The metastable zone width has been somewhat ambiguously defined as “the supercooling at which the first crystals or uncontrolled spontaneous crystallisation is detected when the solution temperature is lowered at a constant rate”. In order to pin down the specifics, a couple of groups have defined the metastable zone width as the supercooling that occurs when the number density of crystals reaches a fixed value – which in effect is determined by the sensitivity of the detection method.

To find out what effect the sensitivity and resolution of a detector has on metastable zone width readings, the team have employed analytical and numerical methods. A deeper understanding of this is neccesary to enable better control of crystallisation processes.

Download the article today to find out more…

Analytical and numerical study of detector sensitivity and resolution effects on metastable zone width
Noriaki Kubota, Masanori Kobari and Izumi Hirasawa
CrystEngComm, 2013, 15, 2091-2098
DOI: 10.1039/C2CE26968F, Paper

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Acid-terminated hybrid POMs

Using linear, rather than cyclic, anhydrides was key to synthesising the carboxylic acid functionalised hybrid polyoxometalates.

Using linear, rather than cyclic, anhydrides was key to synthesising the carboxylic acid functionalised hybrid polyoxometalates

Leroy Cronin and colleagues at the University of Glasgow report a high yield synthesis of carboxylic acid functionalised clusters by reacting Mn-Anderson hybrid polyoxometalates, substituted by an amine group, with anhydride precursors. The terminal acid groups make it possible for the clusters to bind to hydrophilic glass surfaces. Developing understanding of the surface interactions of these hybrids may have potential implications in the development of hybrid based thin films for solar cells.

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Programming the assembly of carboxylic acid-functionalised hybrid polyoxometalates

Marie Hutin, Carine Yvon, Jun Yan, Andrew Macdonell, De-Liang Long and Leroy Cronin
CrystEngComm, 2013
DOI: 10.1039/C3CE26816K, Paper

You may also be interested in the 2012 Dalton Transactions Polyoxometalates themed issue, that was guest edited by De-Liang Long and Leroy Cronin.Dalton Transactions Polyoxometalates themed issue

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Releasing the electronic potential in aluminium nitride

Photo of free-standing AlN wafer

Photo of free-standing AlN wafer

The use of aluminium nitride in solid-state optoelectronic devices has been hindered by high defect levels limiting the output power, efficiency and lifetimes of mid-UV LEDs. Now, there is a possible solution, thanks to the method described in this HOT CrystEngComm paper.

R. Radhakrishnan Sumathi from Ludwig Maximilians University reports a physical vapour transport growth method using silicon carbide as a foreign substrate. The result is a more homogeneous structure than afforded by previous methods with uniform levels of defects and impurities across the wafer.

Read more now…

Bulk AlN single crystal growth on foreign substrate and preparation of free-standing native seeds
R. Radhakrishnan Sumathi
CrystEngComm, 2013
DOI: 10.1039/C2CE26599K

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Role of aspartic acid in regulating the growth of common kidney stones

Yu Huang, S. Roger Qiu and colleagues have used in situ atomic force microscopy to investigate how the growth of calcium oxalate monohydrate is inhibited by 6-residue linear aspartic acid peptides. 

Analysis of the step speed data showed that the aspartic acid enantiomers block active kink sites through step-pinning.

 
Calcium oxalate monohydrate is the main inorganic component in the most common types of kidney stones, so preventing their formation is of great clinical importance.

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Growth inhibition of calcium oxalate monohydrate crystal by linear aspartic acid enantiomers investigated by in situ atomic force microscopy
Kang R. Cho, E. Alan Salter, James J. De Yoreo, Andrzej Wierzbicki, Selim Elhadj, Yu Huang and S. Roger Qiu
CrystEngComm, 2013
DOI: 10.1039/C2CE25936B, Paper

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Building MOFs with 3-pyridylisonicotinamide ligands

Robert LaDuca, and colleagues at Michigan State University, have hydrothermally synthesised divalent metal coordination polymers featuring the ligand, 3-pyridylisonicotinamide (3-pina).  The 3-pina ligand has a hydrogen bonding donor and acceptor locus at its central amide, making supramolecular structure direction achievable, something that is not possible using the regularly tested ligand, 4,4′-bipyridine.

The 3-pyridylisonicotinamide ligand has a kinked disposition of its nitrogen atoms.

The 3-pyridylisonicotinamide ligand has a kinked disposition of its nitrogen atoms.

The team discuss 3 very diverse structures featuring the 3-pina ligand, showing that the dimensionality in the resulting coordination polymers very much depends on the metal coordination environment and the sulfate binding mode that occurs in each case.

Download the paper now to find out more:

Metal dependent dimensionality in sulfate coordination polymers containing 3-pyridylisonicotinamide
Jacqueline S. Lucas, Jacob W. Uebler and Robert L. LaDuca
CrystEngComm, 2012
DOI: 10.1039/C2CE26333E, Paper

Take a look at some of the teams other recent CrystEngComm articles:

Topological diversity in zinc coordination polymers with 5-substituted isophthalate and bis(4-pyridylmethyl)piperazine ligands
Amy L. Pochodylo and Robert L. LaDuca
CrystEngComm, 2011,13, 2249-2261
DOI: 10.1039/C0CE00715C, Paper

Metal and ligand binding mode dependent topologies in phthalate coordination polymers with bis(4-pyridylformyl)piperazine co-ligands
Curtis Y. Wang, Zachary M. Wilseck, Ronald M. Supkowski and Robert L. LaDuca
CrystEngComm, 2011,13, 1391-1399
DOI: 10.1039/C0CE00632G, Paper

Cadmium bis(4-pyridylformyl)piperazine coordination polymers: layered nets and a novel 3,5-connected binodal lattice
Jacqueline S. Lucas, Amy L. Pochodylo and Robert L. LaDuca
CrystEngComm, 2010,12, 3310-3317
DOI: 10.1039/C0CE00117A, Paper

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The diverse crystal forms of rifaximin

Drugs, as with many molecular compounds, often exist in different crystal forms, and in these different forms they will exhibit different chemical and physical properties.  Different solubilities and dissolution rates result in different absorption rates so the ability to control what form crystals take on, is of key importance throughout many stages of the pharmaceutical industry.

The structure–property relationship of four crystal forms of rifaximin

This HOT paper from Braga, Grepioni et al. looks at the crystal structures of four crystal forms of the synthetic antibiotic rifaximin.  The study increases our understanding of how water molecules interact with rifaximin and/or amongst themselves in the crystal packing as well as providing information on the phase relationship of the hydration-dehydration process.

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The structure–property relationship of four crystal forms of rifaximin
Dario Braga, Fabrizia Grepioni, Laura Chelazzi, Manuela Campana, Donatella Confortini and Giuseppe C. Viscomi
CrystEngComm, 2012
DOI: 10.1039/C2CE25920F, Paper

You might also find our recent themed issue on Crystal engineering and crystallography in the pharmaceutical industry interesting.

Are you following us on Twitter?  @crystengcomm

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Screw growth of crystals can copy nature’s spirals

Screw growth of crystals can copy nature's spiralsNacre, a material found on the outer-coating of pearls, has incredible mechanical strength thanks to its arrangement of parallel laminars of inorganic layers separated by organic layers of macromolecules.

Scientists at Zhejiang University, China, have combined calcium phosphate and sodium bis(2-ethylhexyl)sulfosuccinate in the presence of bovine serum albumin to create hybrid crystals with a nacre-like structure. 

The hybrid crystals grew by a classical screw growth mechanism which is similar to the actual biological pathway for nacre formation. Further development of such biomimetic pathways will progress research into new, and perhaps stronger, organic-inorganic composites.

Download the manuscript which will be free to access for 4 weeks.

Lamellar organic–inorganic architecture via classical screw growth
Yan Quan, Halei Zhai, Zhisen Zhang, Xurong Xu and Ruikang Tang
CrystEngComm, 2012
DOI: 10.1039/C2CE25805F, Paper

Are you following us on Twitter?  @crystengcomm

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Chemical Vapour Deposition for engineering oxide nanosystems

Chemical Vapour Deposition-based growth can help tailor the properties of oxide-based nanomaterials.

Chemical Vapour Deposition-based growth can help tailor the properties of oxide-based nanomaterials.

Davide Barreca and colleagues survey the current literature on multi-component oxide nanosystems obtained by Chemical Vapour Deposition (CVD) in their HOT Highlight article.  Three bi-component categories of nanomaterials are discussed in detail; these are metal/oxide, oxide/oxide and carbon/oxide systems.

The metal/oxide materials include zinc oxide-based systems which are some of the most investigated composites obtained by CVD-based methods.  Tin dioxide nanowires covered by iron oxide nanocrystals are an example of the oxide/oxide nanomaterials examined, with CVD techniques being critical for obtaining interconnected magnetite superstructures.  A combined plasma enhanced-CVD and electrodeposition approach to create nanofibers coated with manganese oxide is an example of a carbon/oxides systems.

Future challenges include controlling phenomena occurring at interfaces between the materials but the flexibility of CVD techniques can help with overcoming these to further exploit and develop novel oxide nanosystems.  Download the Highlight today to find out more; it’s free for 4 weeks.

Multi-component oxide nanosystems by Chemical Vapor Deposition and related routes: challenges and perspectives
Daniela Bekermann, Davide Barreca, Alberto Gasparotto and Chiara Maccato
CrystEngComm, 2012
DOI: 10.1039/C2CE25624J, Highlight

Here are some other articles from the team that you might find interesting…

Controlled synthesis and properties of beta-Fe2O3 nanosystems functionalized with Ag or Pt nanoparticles

Giorgio Carraro, Davide Barreca, Elisabetta Comini, Alberto Gasparotto, Chiara Maccato, Cinzia Sada and Giorgio Sberveglieri
CrystEngComm, 2012
DOI: 10.1039/C2CE25956G, Paper

Strongly oriented Co3O4 thin films on MgO(100) and MgAl2O4(100) substrates by PE-CVD

Davide Barreca, Anjana Devi, Roland A. Fischer, Daniela Bekermann, Alberto Gasparotto, Marco Gavagnin, Chiara Maccato, Eugenio Tondello, Elza Bontempi, Laura E. Depero and Cinzia Sada
CrystEngComm, 2011, 13, 3670-3673
DOI: 10.1039/C1CE05280B, Communication

Malonate complexes of dysprosium: synthesis, characterization and application for LI-MOCVD of dysprosium containing thin films
Andrian P. Milanov, Rüdiger W. Seidel, Davide Barreca, Alberto Gasparotto, Manuela Winter, Jürgen Feydt, Stephan Irsen, Hans-Werner Becker and Anjana Devi
Dalton Trans., 2011, 40, 62-78
DOI: 10.1039/C0DT00455C, Paper

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Porous aromatic frameworks

Teng Ben and Shilun Qiu discuss porous aromatic framework network formation and the relationship between secondary building units and function in this hot Highlight article.  The ability to control the pore size in porous aromatic frameworks lends itself to numerous applications, including in molecular separation, catalysis, photoelectric materials, clean energy and carbon dioxide capture and storage.

You can download the full article below, which is free to access for 4 weeks.

Porous aromatic frameworks: Synthesis, structure and functions
Teng Ben and Shilun Qiu
CrystEngComm, 2012
DOI: 10.1039/C2CE25409C, Highlight

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