CrystEngComm Blog

In this CrystEngComm Hot article, Michael Lorenz and colleagues from Universitat Leipzig have made fresnoite thin films, fused on various materials by pulsed laser deposition, for use in photonic applications.

The mineral fresnoite (Ba₂TiSi₂O₈)was discovered in California in 1965, and has become increasingly interesting to chemists because of its luminescence, non-linear optic and ferroelectic properties. In this work the authors examine the understudied films of these minerals, focussing on their growth using pulsed laser deposition, which hasn’t been done before.

Lorenz and coworkers found that the fresnoite films had high photoluminescence intensity, and were able to use a laser to ‘write’ on the films, which induced local crystallisation. They think this will open the door for many applications of their films, including potentially ‘security features against product piracy or individualized branding of products’.

Read the full article for FREE to find out more about writing on the amorphous fresnoite films…

Fresnoite thin films grown by pulsed laser deposition: photoluminescence and laser crystallization
Alexander Müller, Michael Lorenz, Kerstin Brachwitz, Jörg Lenzner, Kai Mittwoch, Wolfgang Skorupa, Marius Grundmann and Thomas Höche
CrystEngComm, 2011, DOI: 10.1039/C1CE05265A

In this CrystEngComm Hot Article, Shaodong Sun et al. prepared polyhedral 50-facet cuprous oxide crystals with high-index planes using a seed-mediated solution phase route.

Cuprous oxide is a p-type semiconductor with potential applications including solar energy conversion, catalysis, gas sensors and lithium-ion batteries.

The authors studied the growth mechanism of the crystals, which will aid the design and synthesis of new polyhedral cuprous oxide architectures.

They also studied the photocatalytic activity of the crystals in the degradation of Methyl Orange dye. The crystals with high-index facets exhibited higher catalytic activity than crystals with low-index facets.

Find out more for FREE until 15th June 2011:

Seed-mediated synthesis of polyhedral 50-facet Cu₂O architectures
Shaodong Sun, Dongchu Deng, Chuncai Kong, Yang Gao, Shengchun Yang, Xiaoping Song, Bingjun Ding and Zhimao Yang
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05243H, Communication

In this HOT article, the Joester group, show for the first time the synthesis and stabilization of amorphous calcium carbonate (ACC) nanoparticles in phosphatidylcholine liposomes (vesicles).  There is exactly one nanoparticle per liposome, and the ACC is stable over time (it does not crystallize for at lease 20 h).

The authors have also observed ACC nanoparticles of up to
200 nm in liposomes extruded through a 1 mm pore size membrane.  Showing no sign of faceting or crystallization, these are the largest ACC nanoparticles stabilized by confinement thus far.

The liposomal encapsulation strategies in combination with in situ imaging, scattering, and spectroscopy will aid in characterizing subsequent phase transformations and polymorph selection in the
nucleation and growth not only of calcium carbonate, but also other (bio)-minerals, pharmaceuticals, and proteins.

Read more for FREE at:
In vitro synthesis and stabilization of amorphous calcium carbonate (ACC) nanoparticles within liposomes
Chantel C. Tester, Ryan E. Brock, Ching-Hsuan Wu, Minna R. Krejci, Steven Weigand and Derk Joester
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05153A

MOF have been much studied due to their potential applications from their excellent physical and chemical properties, however, many are unlikely to realize their potential due to the expense of the starting materials and/or complexity of the synthesis involved.  In this HOT article, Day and co-workers have formed stable cucurbit[5]uril MOF structures as ‘beaded’ rings built on a p-hydroxybenzoic acid template prepared readily by self-assembly as a supramolecular structure that remarkably can be recrystallised from water to form the same stoichiometry and structure as occurs under the initial crystallisation conditions.  Accessible channels have clearly been demonstrated for a group of polar volatile organic molecules with significant absorption selectivity for at least three examples.

Read more about these interesting porous structures for FREE at:

Stable cucurbit[5]uril MOF structures as ‘beaded’ rings built on a p-hydroxybenzoic acid template—a small molecule absorption material
Xing Feng, Kai Chen, Yun-Qian Zhang, Sai-Feng Xue, Qiang-Jiang Zhu, Zhu Tao and Anthony I. Day
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05051F

How does one control and modify the self-assembly process of organic molecules towards a desired solid state? Andreas Lemmerer, Joel Bernstein and Volker Kahlenberg ask themselves this very question in their recent CrystEngComm Hot Article. In their paper the group tell us how they modify the hydrogen bonding in isonicotinic acid hydrazide (isoniazid) in order to control the self-assembly process.

Isoniazid is an active pharmaceutical ingredient that helped cure tuberculosis as part of a triple therapy cocktail. It co-crystallizes with carboxylic acids to form pharmaceutical co-crystals and is also a versatile supramolecular reagent as it has multiple donor and accepting groups to interact with different functional groups. Find out more about this study and Isoniazid in the article – FREE to read until 31 May 2011.

Covalent assistance in supramolecular synthesis: in situ modification and masking of the hydrogen bonding functionality of the supramolecular reagent isoniazid in co-crystals
Andreas Lemmerer, Joel Bernstein and Volker Kahlenberg
CrystEngComm, 2011, Advance Article   DOI: 10.1039/C1CE05152K, Paper