Author Archive

Nanocubic silver gives enhanced SERS effect

In this HOT article, Shengchun Yang and co-workers describe the preparation of porous Ag nanocubes by synthesizing Ag3PO4 nanocubes and using them as hard templates. With the addition of strong reducing agents, Ag is reduced in situ to form porous Ag.  The resulting Ag showed good SERS (surface enhanced Raman scattering) properties by detecting nanomolar concentrations of Rhodamine 6G.

Volume shrinkage induced formation of porous Ag sub-microcubes via solid–liquid reaction for SERS

Volume shrinkage induced formation of porous Ag sub-microcubes via solid–liquid reaction for SERS

Find out more by downloading the full paper now:

Volume shrinkage induced formation of porous Ag sub-microcubes via solid–liquid reaction for SERS
Xiao Luo, Shaomin Lian, Liqun Wang, Shengchun Yang, Zhimao Yang, Bingjun Ding and Xiaoping Song
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C3CE27089K

You may also be interested in other publications concerning SERS and noble metals from recent studies by the same author:

A new route for the synthesis of polyhedral gold mesocages and shape effect in single-particle surface-enhanced Raman spectroscopy
Jixiang Fang, Sergei Lebedkin, Shengchun Yang and Horst Hahn
Chem. Commun., 2011, 47, 5157-5159
DOI: 10.1039/C1CC10328H

Interface synthesis of gold mesocrystals with highly roughened surfaces for surface-enhanced Raman spectroscopy
Hongjun You, Yuetian Ji, Liang Wang, Shengchun Yang, Zhimao Yang, Jixiang Fang, Xiaoping Song and Bingjun Ding
J. Mater. Chem., 2012, 22, 1998-2006
DOI: 10.1039/C1JM13211C, Paper

Also, keep up to date and follow us on twitter: @crystengcomm

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Halogen bonding: competitive and directional?

Hydrogen versus halogen bonding in the solid state
Hydrogen versus halogen bonding in the solid state

 

The Gamez group have analyzed halogen–π interactions by a statistical study of the occurrence and directionality of the interactions in the solid-state.  They used structures from the Cambridge Structural Database (CSD) in combination with an analytical procedure developed and used previously by the authors for other important interactions like lone pair–π and anion–π interactions. The results clearly demonstrate that halogen bonding to a phenyl ring are directional, and could compete with hydrogen bonding. Read more about competition and directionality in the solid state for FREE at:

Halogen-phenyl supramolecular interactions in the solid state: hydrogen versus halogen bonding and directionality
Tiddo J. Mooibroek and Patrick Gamez
CrystEngComm, 2013, 15, 1802-1805
DOI: 10.1039/C2CE26853A 

Other related reading from the same group includes:

Anion–arene and lone pair–arene interactions are directional
Tiddo J. Mooibroek and Patrick Gamez
CrystEngComm, 2012, 14, 1027-1030
DOI: 10.1039/C1CE05946G

How directional are D–H phenyl interactions in the solid state (D = C, N, O)?
Tiddo J. Mooibroek and Patrick Gamez
CrystEngComm, 2012, 14, 8462-8467
DOI: 10.1039/C2CE26205C

You may also be interested in: 

Competing hydrogen-bond and halogen-bond donors in crystal engineering
Christer B. Aakeröy,  Sheelu Panikkattu,  Prashant D. Chopade and John Desper
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C2CE26747K 

or also on our blog 

Follow us on Twitter:  @crystengcomm

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Halogen vs. hydrogen bonding

Competing hydrogen-bond and halogen-bond donors in crystal engineering

Competing hydrogen-bond and halogen-bond donors in crystal engineering

In this HOT article by Aakeröy et al, relevant hydrogen-bond and halogen-bond acceptors and donors were selected to study the competition between these two molecular interactions in supramolecular assembly.  Twelve co-crystals were synthesized based on two different azobipyridines as acceptors and six donor molecules possessing both hydrogen-bond and halogen-bond moieties.  The key conclusions which could be drawn from the study were: (i) the hydrogen-bond is the principal driving force in the formation of 3,3′-azabipyridine co-crystals whereas hydrogen and halogen bonds do indeed compete in the formation of the 4,4′-azabipyridine co-crystals; (ii) the iodine donor appears to be a better halogen-bond donor than bromine; and  (iii) the three different hydrogen-bond donors studied (–COOH, –OH and –CN(R)OH) behave similarly.

Read more for FREE at:

Competing hydrogen-bond and halogen-bond donors in crystal engineering
Christer B. Aakeröy ,  Sheelu Panikkattu ,  Prashant D. Chopade and John Desper
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C2CE26747K

This article will be published in a forthcoming themed issue on Halogen bonding, other highlights include:

Iodo-imidazolium salts: halogen bonding in crystals and anion-templated pseudorotaxanes
Antonio Caballero,  Sam Bennett,  Christopher J. Serpell and Paul D. Beer
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C2CE26020D

Halogen bonding at work: recent applications in synthetic chemistry and materials science
Franck Meyer and Philippe Dubois
CrystEngComm, 2013, Advance Article
DOI: 10.1039/C2CE26150B

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Polymorphism co-crystal screening

In their HOT article, Jones and co-workers at the University of Cambridge present a comprehensive crystal form screen for the phenazine:mesaconic acid system, employing a variety of different co-crystallisation methods.
 
Phenazine:mesaconic acid system
Phenazine:mesaconic acid system

The researchers identified and characterised three anhydrous co-crystal polymorphs, one co-crystal hydrate and one DMSO co-crystal solvate, and also highlighted a novel co-crystallisation technique at the interface between two immiscible solutions, yielding a pure phenazine:mesaconic acid co-crystal form.   Traditional solvent-based methods usually used for polymorphism screening were inappropriate for this system due to the large differences in solubility of phenazine and mesaconic acid.

Read more about this study for FREE at:

Screening for polymorphs of cocrystals: a case study
Mark D. Eddleston, Saranja Sivachelvam and William Jones
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE26496J

You may also be interested in other recent work on co-crystals by the Jones group:

Cocrystal dissociation and molecular demixing in the solid state
Mark D. Eddleston, Gareth O. Lloyd and William Jones
Chem. Commun., 2012, 48, 8075-8077
DOI: 10.1039/C2CC33412G, Communication

A hydrogen bonded cocrystal with an unusual interweaving between the adjacent triple-helices
Amit Delori and William Jones
CrystEngComm, 2011, 13, 6315-6318
DOI: 10.1039/C1CE05534H, Communication

Observation of a two-dimensional halogen-bonded cocrystal at sub-monolayer coverage using synchrotron X-ray diffraction
Stuart M. Clarke, Tomislav Frišcic, William Jones, Anasuya Mandal, Chenguang Sun and Julia E. Parker
Chem. Commun., 2011, 47, 2526-2528
DOI: 10.1039/C0CC04400H, Communication

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H-bonds under pressure

Crystal growth of aniline-II at 0.8 GPa

Crystal growth of aniline-II at 0.8 GPa

In an extension to previous work showing that H-bond lengths are pressure sensitive, Parsons and co-workers used the PIXEL method (a computational method for structural prediction) to study the variation in energy of intermolecular interactions with pressure, in two crystalline phases of aniline.  

For aniline II, at a pressure of 7.3 GPa, the pressure-induced shortening of the H-bonds was found to go beyond the Cambridge Structural Database limit with the H-bonds being similar in energy to the CH-π contacts.

This ability to manipulate the hierarchy of intermolecular interactions by high pressure could have potentially important implications in crystal engineering.

Read more for FREE about the use of high pressure in crystalline solids at:

Destabilisation of hydrogen bonding and the phase stability of aniline at high pressure
Nicholas P. Funnell, Alice Dawson, William G. Marshall and Simon Parsons
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE26403J, Paper

You may also want to check out previous work from Simon Parsons:

Alanine at 13.6 GPa and its pressure-induced amorphisation at 15 GPa
Nicholas P. Funnell, William G. Marshall and Simon Parsons
CrystEngComm, 2011, 13, 5841-5848
DOI: 10.1039/C1CE05487B, Paper

The effect of pressure on the crystal structure of L-alanine
Nicholas P. Funnell, Alice Dawson, Duncan Francis, Alistair R. Lennie, William G. Marshall, Stephen A. Moggach, John E. Warren and Simon Parsons
CrystEngComm, 2010, 12, 2573-2583
DOI: 10.1039/C001296C, Paper

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Photodimerization control in the solid state

In an extension of previous work,  this HOT Article, by Kraig Wheeler and co-workers describes their attempts to control the regio- and stereochemical outcomes of [2+2] photochemical dimerization in the solid state.

In their 2011, CrystEngComm article, the team reported on the development of a sulfonamidecinnamic acid framework which could be likened to the shape of a fish-hook. Upon crystallisation, the structures form supramolecular dimers where the neighbouring C=C double bonds are oriented mutally co-planar. It is this feature that allows UV initiated dimerisation into the corresponding cyclobutane product.

Solid-state photodimerization reactions of racemic and homochiral phenylalanine sulfonamidecinnamic acids

In their latest CrystEngComm, they extend this study by looking at a greater range of frameworks with different R substituents. To see what impact this has on the supramolecular photodimerisation, download the article now for FREE:

Solid-state photodimerization reactions of racemic and homochiral phenylalanine sulfonamidecinnamic acids
Zhiqing Yan, Andrew J. Bolokowicz, Teage K. Collett, Sarah A. Reeb, Joshua D. Wiseman and Kraig A. Wheeler
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE26307F

Also of interest:
Enantiocontrolled solid-state photodimerizations via a chiral sulfonamidecinnamic acid
Kraig A. Wheeler, Joshua D. Wiseman and Rebecca C. Grove
CrystEngComm, 2011, 13, 3134–3137
DOI: 10.1039/C0CE00516A

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From disorder to order: evidence of stable ion clusters

Evidence for an amorphous to crystalline transition
In this HOT Article, Franca Jones suggests the existence of highly disordered clusters that form prior to crystallization of barite and gypsum, based on  Fourier-Transform infra-red (FTIR) spectra of saturated solutions as they crystallize.  Jones reports the  evolution of various mineral phases prior to the appearance of the crystalline mature product and in the case of barite, shows that the FTIR evidence is strongly supported by electron diffraction. The role of water in the process is also investigated… 

Read more for FREE at: 

Infrared investigation of barite and gypsum crystallization: Evidence for an amorphous to crystalline transition
Franca Jones
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE25918D 

Also of interest may be: 

Barium sulfate crystallization dependence on upper rim calix[4]arene functional groups
Andrew Baynton, Mark I. Ogden, Colin L. Raston and Franca Jones
CrystEngComm, 2012, 14, 1057-1062
DOI: 10.1039/C1CE06083J

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Supramolecular engineering via halogen bonding

Applications of halogen bonding

Applications of halogen bonding

l

In this HOT Highlight, Franck Meyer and Philippe Dubois discuss the emergence of halogen bonding over the last decade for crystal engineering of supramolecular complexes. Whilst hydrogen bonding has received a great deal of interest in this respect, very little work has focused on halogen bonding until now. The first applications to highly functional materials are presented. Other recent applications have also included solution phase recognition (catalysis, anion sensing and resolution) and macromolecular organizations (porous, polymeric and hybrid systems). Thus, the potential cooperation between weak
non-covalent bonds opens the door for new applications in materials science and synthetic chemistry.

Read more for FREE at:

Halogen bonding at work: recent applications in synthetic chemistry and materials science
Franck Meyer and Philippe Dubois
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE26150B

Also of interest:

Controlled room temperature ROP of L-lactide by ICl3: a simple halogen-bonding catalyst
Olivier Coulembier, Franck Meyer and Philippe Dubois
Polym. Chem., 2010,1, 434-437
DOI: 10.1039/C0PY00013B, Communication

Mesogenic, trimeric, halogen-bonded complexes from alkoxystilbazoles and 1,4-diiodotetrafluorobenzene Duncan W. Bruce, Pierangelo Metrangolo, Franck Meyer, Carsten Präsang, Giuseppe Resnati, Giancarlo Terraneo and Adrian C. Whitwood
New J. Chem., 2008, 32, 477-482
DOI: 10.1039/B709107A, Paper

Solid state synthesis under supramolecular control of a 2D heterotetratopic self-complementary tecton tailored to halogen bonding
Giovanni Marras, Pierangelo Metrangolo, Franck Meyer, Tullio Pilati, Giuseppe Resnati and Ashwani Vij
New J. Chem., 2006, 30, 1397-1402
DOI: 10.1039/B605958A, Paper

Crystal engineering of brominated tectons: N-methyl-3,5-dibromo-pyridinium iodide gives particularly short C–BrI halogen bonding
Thomas A. Logothetis, Franck Meyer, Pierangelo Metrangolo, Tullio Pilati and Giuseppe Resnati
New J. Chem., 2004, 28, 760-763
DOI: 10.1039/B401421A, Paper

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Polymorphism in ionic liquids

Ethambutol dibenzoate trimorphs

Ethambutol dibenzoate trimorphs

Cherukuvada and Nangia report the first example of polymorphism in ionic liquids.  Three polymorphs of ethambutol dibenzoate were crystallized as ionic liquids and characterized.  15N NMR spectroscopy was used to identify the three polymorphs and their stability was investigated with the use of DSC and other experiments.  The polymorphic transformations from forms 1 to 3 were also investigated by PXRD.   Further work on crystallization and characterization will prove useful for new pharmaceutical formulations.

Read more for FREE at:

Polymorphism in an API ionic liquid: ethambutol dibenzoate trimorphs
Suryanarayan Cherukuvada and Ashwini Nangia

CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE25842K

Also of interest:

Polymorphs of 1,1-bis(4-hydroxyphenyl)cyclohexane and multiple Z’ crystal structures by melt and sublimation crystallization
Bipul Sarma, Saikat Roy and Ashwini Nangia
Chem. Commun., 2006, 4918-4920
DOI: 10.1039/B610323E, Communication

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Hydrogels for studying biomineralisation

Hydrogel-based double-diffusion systems for studying biomineralization

Hydrogel-based double-diffusion systems for studying biomineralization

This Highlight presents an overview of hydrogel-based double-diffusion systems to study biomineralization.  The authors describe two types of diffusion systems: static and dynamic.  They evaluated four such systems to design  an optimized system taking into account the type of hydrogel, the boundary conditions and design strategy.

Gels represent a good model to study and understand biomineralization because the mineral deposition that occurs in many mineralization processes  in vivo takes place in gelling environments; however,  they are not often used due to their complexity and poor knowledge of ionic diffusion.

Read more about biomineralisation for FREE at:

Rediscovering hydrogel-based double-diffusion systems for studying biomineralization
Jason R. Dorvee , Adele L. Boskey and Lara A. Estroff
CrystEngComm, 2012, Advance Article
DOI: 10.1039/C2CE25289A

Other articles by Lara A. Estroff and co-workers which may also be of interest are:

Gel incorporation inside of organic single crystals grown in agarose hydrogels
Hanying Li, Yuzo Fujiki, Kazuki Sada and Lara A. Estroff
CrystEngComm, 2011, 13, 1060-1062
DOI: 10.1039/C0CE00118J, Communication

Porous calcite single crystals grown from a hydrogel medium
Hanying Li and Lara A. Estroff
CrystEngComm, 2007, 9, 1153-1155
DOI: 10.1039/B709068D, Communication
From themed issue: CrystEngComm focuses on biomineralisation

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